Program Setup

Getting Familiarized with All Three Programs.

GetAccess.exe. 7

Managing the database of the realtime and historical web data 7

Setting the Database Connection String: 7

SITE LIST button. 8

PARAMETERS w/data button. 9

GO button. 9

Graph/Table button. 10

Excel Workbook “DBedit.xls”. 13

Excel Workbook “DBretrieve.xls”. 14

Creating Your Own Database… for these data sources. 15

Wunderground. 16

US Geological Survey

California Data Exchange Center

US Conservation Service

US Bureau of Reclamation

US Army Corps of Engineers

California Irrigation and Management Information System

NOAA Radar WSR-88D Imagery

Datatype_ID Table

DB Tables. 28

GetRealtime.exe. 31

Retrieval and computations of realtime web data 31

Setting the Database Connection String: 31

Description of the controls on the GetRealtime form: 32

Adding Sites to the GetRealtime Station List: 35

Computation Examples on the GetRealtime Station List: 37

Computation from Multiple Stations (averaging gages example)

Rainfall-Runoff from Wunderground Gage

Triangular Unit Graph

NEXRAD Radar Point and Area Rainfall

Flow Routing

NEXRAD NVL, NET, N0S, N0V

Radar Image Maximums

NEXRAD Ridge2 Testbed

Snowpack and Melt Simulation

GetGraphs.exe. 44

Displaying the realtime data and web screens 44

Setting the Database Connection String: 44

Right mouse click on a graph or web screen to bring up menu. 45<

Adding Sites to the GetGraphs Setup: 48

Working with Web Screens: 1

GetGraphs Flow Routing

Program Setup

Follow the instructions on the Free Downloads page to download the setup file and run setup.  If you will be using GetGraphs.exe ONLY, then you can skip all the GetRealtime and GetAccess sections and go directly to Working with Web Screens at the end of this document.

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Jump Start Tutorial for GetAccess, GetRealtime, and GetGraphs:

1) Download the setup file 'setupGetRealtime.exe' and run to install the programs GetAccess, GetRealtime, and GetGraphs.  If you do not have Microsoft Access or Microsoft Office installed on your computer then you can download the 'Download MSoA Support' zip file from the Free Downloads page, unzip and click on the file ACCESSRT.MSI to install the Access2003 runtime engine on your computer.

2) Fire up GetAccess and a list of example stations should be displayed. If the list appears then GetAccess connection string is correct for this example and you can close GetAccess. If a connection error occurs then click the 'Connection' button and set the connection string to where the example 'GetAccessHDB.mdb' file is located (C:\Program Files\GetRealtime\GetAccess\GetAccessHDB.mdb). Then click the 'SITE LIST' button to display the example stations.

3) Fire up GetRealtime. Set the 'Days' to 7. Click 'Start Realtime Retrieval' button. This will retrieve the past 7 days of daily and hourly values for the 107 stations on the station list and write them to the GetAccess database. If you had to change the GetAccess databse connection string in step 2 above, then before retrieving click the 'Select Station from List' button then click the 'Connection' button and set the connection string to what you set in step 2 and be sure to click the 'Save' button after changing the connection string.

4) After retrieving the 107 example stations data for the past week in step 3 we can view the data. Fire up GetGraphs and severl graphs of rainfall data should be displayed as well as a web page in the upper right. Some of these example stations and web pages may no longer be available. Click on any graph to continue viewing more data graphs. If you had to change the connection string in steps 2 and 3 above then you will have to change GetGraphs connection also. To change the connection string, close GetGraphs, open Windows Explorer, find the GetGraphs installed direcory (C:\Program Files\GetRealtime\GetGraphs). Double click on the file 'GetGraphs_setup.txt'. This will open the Notepad editor and you can change the connection string to that of steps 2 and 3 above. Windows Explorer can also be used to edit the setup files in steps 2 and 3 and may be preferred by most users.

5) That's it. After following the steps above you now have a good idea of what the rest of this help page is talking about.

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Getting Started Video:

Getting Familiarized with All Three Programs

The user should become familiar with each program.  For help see the programs section below for Program Use.  The following sections are as follows:

1) GetAccess.exe program use.

2) Creating your own database.

3) GetRealtime.exe program use.

4) Creating your own station list.

5) GetGraphs.exe program use.

6) Creating your own graph and web site list.

One should become familiar with the 3 programs in steps 1, 3, and 5 above followed then with steps 2, 4, and 6.  After following the examples for creating your own database, station list, and graph list then you will be ready to implement your own sites.

The hourly and daily data in the MS Access database should be updated for the past 7 days using GetRealTime.exe after reading GetRealtime section on how to do that.

Program Use

GetAccess.exe

(Managing the database of the real-time and historical web data)

Setting the Database Connection String:

If GetAccess.exe cannot make a connection to the Access database the following message will appear.  Set the connection string to the GetAccessHDB.mdb database using the Connection button.

The connection string should look similar to this depending on the path where GetRealtime.exe files were installed:

Driver={Microsoft Access Driver (*.mdb)};DBQ=

C:\Program Files\GetRealtime\GetAccess\GetAccessHDB.mdb;Uid=Admin;Pwd=Me;

The Connection button can also be used to compact the database and make a backup.

The before and after database compacting file size will be displayed.  The backup database file is named GetAccessHDB_backup.mdb.

Once connected, the example sites that are already in the GetAccess.mdb database can be displayed with the SITE LIST button.  The real-time data should be updated for the past 7 days using GetRealTime.exe so that the following examples can be followed.  You will need to get familiar with the programs using the provided examples because you will want to replace the example data with your own data (See Creating Your Own Database section below).

Notice also that an SQL statement is also displayed that was used to get the data from the database, in this case:

SELECT DISTINCT site_id, station_id, site_name, state, reach_id FROM rsite ORDER BY site_id;

Some users may wish to use SQL statements to interact with the database by checking the SQL checkbox and entering an SQL statement and then pressing the GO button.  Normally, all the queries needed are provided through the buttons, but SQL can be handy when deleting data from the database where the data can be SELECTed and then the SQL statement edited to DELETE or UPDATE data instead of SELECT data and removing the ORDER BY.  WARNING!!!!! DO NOT TRY THIS UNTIL VERY FAMILIAR WITH THE DATABASE AND HAVE MADE DATABASE BACKUPS!!!

To display retrieved data, select the time step Hour, select a station from the SITE LIST, and press the PARAMETERS w/data button.  The parameters available for the default date range of the past 7 days and the selected Hour time step will be displayed.

Select the parameter to display by clicking on the parameter row, in this case only one parameter is available for this time step and date range.  Press the GO button and the values in the database table rhour for datatype_site_id, date_time, value, and source are displayed

Notice again the SQL statement used for the database query.

To view the data as a graph or table press the Graph/Table button and the following form will be displayed:

Select GRAPH to view data as a graph.

Use the mouse Right Click button for the graph menu.

Select VIEW and checkbox Table to view data in an hourly table format.

Select SAVE or PRINT to save or print.

Sometimes bad or missing data will be retrieved and you may wish to edit it.  If several values are missing or bad, then UPDATE database with Excel can be selected to use the abilities of Excel to quickly fix or fill in missing or bad data, if you have Excel installed.

The provided Excel Workbook “DBedit.xls” will open and the data values automatically loaded into it.  After editing the data, select the revised data range and press the Update Selection to write the data to the database.  Since you have changed the hourly values you may wish to edit the daily value.  You can use the Excel auto sum (or average) of selected values displayed at the bottom of the Excel screen to obtain the new daily value.  When finished, close the Excel workbook and do not save the data, or you may save it with a different name if you wish.

Another Excel workbook that is provided that can be used as a stand alone for accessing the database directly is “DBretrieve.xls” with which you can both retrieve and edit the database values:

The connection string cell may need updating to something similar to:

Driver={Microsoft Access Driver (*.mdb)};DBQ=

C:\Program Files\GetRealtime\GetAccess\GetAccessHDB.mdb;Uid=Admin;Pwd=Me;

To test the connection, press the id list button and a list of all the data sites and parameters will be displayed.

You might find this workbook helpful if you need to create a workbook for processing the real-time data further, such as Crop water use for several crops from ET.

You may also be interested in the simple VBA code behind the Retrieve Data button and the Update Selection button.  You can view the VBA code in Excel by using the Excel menu Tools/Macro/Visual Basic Editor.  It may be desirable to change your current Excel workbook by adding similar code.  If you are not familiar with Excel buttons and VBA code then a little Googleing of Excel on the web should get you started.

Creating Your Own Database… for your own data sites

Once you have become familiar with GetRealtime.exe, GetGraphs.exe, and GetAccess.exe with the example stations provided, you will then want to delete all the example data in the database and add your stations of interest.  Don’t delete the data in the table ExampleRsite because you may need to refer to it when adding info to your table Rsite for each type of data you decide you want to add. 

1)      Open GetAccess.exe.  We will be working with the GetAccessHDB.mdb file located in the GetRealtime directory that was used for the examples, so make sure you have a backup copy using Windows Explorer.

2)      We will proceed to delete all the data in the tables EXCEPT FOR THE TABLE EXAMPLERSITE.  You can copy and paste rows from ExampleRsite table to your new Rsite table and edit the appropriate fields if needed.

3)      For all the other tables follow this example for deleting all the data in Ryear.  Check the SQL checkbox and enter the SQL statement “DELETE * FROM ryear” and press GO.

Continue deleting data in all the database tables EXCEPT ExampleRsite.

DELETE * FROM ryear;

DELETE * FROM rmonth;

DELETE * FROM rday;

DELETE * FROM rhour;

DELETE * FROM runit;

DELETE * FROM rdaymax;

DELETE * FROM rdaymin;

DELETE * FROM runitshift;

DELETE * FROM rupdate;

DELETE * FROM rsite;

4)      You now need to locate the data you want to retrieve on the web to make sure it exists.  Each supported web source has its own Station IDs and Parameter Codes.  Once you determine the data exist you will also know the parameter code needed to retrieve it.  Here are the methods for finding the needed Station ID and Parameter Code for each supported data source:

Wunderground weather data:  http://www.wunderground.com

Using your web browser, enter the web link.  On the left hand side of the Wunderground web page locate the WunderMap.  Click on the WunderMap and you will be able to locate weather stations of interest to you.  Hint:  Click on Terrain and turn off NEXRAD radar to speed things up.  You may need to zoom in or out to move around the country and find a weather station.  Once you locate the weather station, click on its symbol.

In this example, the clicked on Wunderground station shows it to be Station ID KLAS.  Click on the KLAS link in the balloon and the station data for the current day will be displayed.  To determine the Parameter Codes available at this station, locate the Comma Delimeted File link at the bottom of the values table.  Click on it and you will see the available Parameter Codes:

TimePST,TemperatureF,Dew PointF,Humidity,Sea Level PressureIn,VisibilityMPH,Wind Direction,Wind SpeedMPH,Gust SpeedMPH,PrecipitationIn,Events,Conditions
12:56 AM,51.1,25.0,36,30.10,10.0,SSW,4.6,-,N/A,,Clear
1:56 AM,50.0,24.1,36,30.11,10.0,South,3.5,-,N/A,,Clear
2:56 AM,50.0,24.1,36,30.10,10.0,SSW,6.9,-,N/A,,Clear

To retrieve rainfall for this example, the Station ID is KLAS and Parameter Code is PrecipitationIn.  Note that Wunderground stations with Station ID’s of 4 characters like KLAS are airports and have different Parameter Codes than other stations.

US Geological Survey stream flow and water quality data:  http://waterdata.usgs.gov/nwis/rt

Using your web browser, enter the web link.  Click on the state where the station is located.  Near the top of the screen locate the Predefined Displays.  Using the drop down list select  either Stream flow Table, Precip Table, Reservoir Table, or Water Quality Table.  Hit the Go button to get the list of available Stations.  Click on the desired Station ID number to get a list of the available Parameter Codes.

The available real-time Parameter Codes for Station ID 094196781 on Flamingo Wash are 65, 60, and 45

California Data Exchange Center stream flow, reservoir, snowpack, and meteorological:  http://cdec.water.ca.gov/cgi-progs/staSearch

Using your web browser, enter the web link.  Locate the desired Station by checking River Basin and selecting the basin of interest, in this case American R:

From the list of available Station IDs select FOL for Folsom Dam and you will get a list of available parameter names and time steps.  The available hourly time step parameters are:

But this still doesn’t get us the Parameter Codes.

This link will give you a list of Parameter Codes:  http://cdec.water.ca.gov/misc/senslist.html

The numeric Sensor No is the Parameter Code we are after:

For our example of Folsom Dam reservoir elevation, the Station ID is FOL and the Parameter Code is 6.

US Conservation Service SNOTEL snowpack, and meteorological:

http://www3.wcc.nrcs.usda.gov/nwcc/sitelist.jsp

Using your web browser, enter the web link for a list of available Station ID’s.  The numeric Site ID is the value we are after.  For Happy Jack, AZ the Site ID is 969.

Click on the AZ Site Name Happy Jack to get a table of available data:

Click on Hourly – Last 7 Days to find the Parameter Codes:

The available SNOTEL Parameter Codes are Snow Water Equivalent, Snow Depth, Precipitation, and Temp.  So for the station Happy Jack’s water content, the Station ID is 969 and the Parameter Code is Snow Water Equivalent.

US Bureau of Reclamation reservoir, stream flow, evapotranspiration and meteorological:   There are two USBR regions providing real-time data, Great Plains Region and Pacific Northwest Region. 

Starting with the Great Plains Region’s Hydromet:

http://www.usbr.gov/gp/hydromet/station_list_by_state.cfm

Using your web browser, enter the web link for a list of states covered.  Choose a state from the second list, Real-Time values (one value every 15, 30, or 60 minutes).  For this example North Dakota is chosen.

The available stations and Parameter Codes are listed for North Dakota:

For Jamestown Reservoir, the Parameter Code for Reservoir Elevation is FB, but we still need the Station ID.  Click on the Jamestown Reservoir link to find the Station ID:

In this example, the Station ID for Jamestown Reservoir is JAMR.

The USBR provides both 15-minute and 60-minute time steps.  Some values are only available as 60-minutes.  Using your web browser retrieve the data and see which time step you want and then the Parameter Code you will use is 15-FB or 60-FB for reservoir elevation.

The Pacific Northwest Region Hydromet and Agrimet:

http://www.usbr.gov/pn/hydromet/decod_params.html

Both the Station ID and available Parameter Codes are listed... but it’s a long list.  For air temperature at station Afton Wyoming, the Station ID is AFTY and Parameter Code is OB.  You may wish to look around on the USBR Hydromet and Agrimet web pages for easier ways to find stations.  Try retrieving the data to determine the time steps available.

The USBR provides both 15-minute and 60-minute time steps.  Some values are only available as 60-minutes.  Retrieve the data and see which time step you want and then the Parameter Code you will use is 15-OB or 60-OB.

US Army Corps of Engineers reservoirs, canals, streams and weather data:   http://www2.mvr.usace.army.mil/WaterControl/new/layout.cfm

Find your station of interest and display the data in order to determine the station ID code and parameter name:

Forthis example you would select Station ID from your web browsers URL web page address. The Station ID is highlighted above and is 'CCLK2'. The parameter code is highlighted at the top of the data fields table and is 'Stage' and is case sensitive. You will use these two codes in the GetRealtime_setup.txt and your GetAccess HDB rsite table:

 GetRealtime_setup.txt:  (Add COE- to Station ID)

GetAccess HDB rsite table:  (But not here, just CCLK2)

California Irrigation and Management Information System evapotranspiration and meteorological:   http://wwwcimis.water.ca.gov/cimis/infoStnMap.jsp

Find Station ID 80 in the San Joaquin area and click on it:

We have the Station ID 80.  The Parameter Codes are on the following table:

ETo for the station Fresno has a Station ID of 80 and a Parameter Code of 6.

NOAA NEXRAD WSR-88D class radar imagery--These images are provided free on the web and are updated about every 5 minutes:   http://radar.weather.gov/

The radar imagery provides for computation of area average rainfall amounts for any area in the USA.  This is a new addition and is described at the bottom of this page.

Your Personal Weather Station or Other Text Files--Text files from your weather station can be added to the Access Database.  The text file must have a date and time and value columns and can be either Space, Comma, SemiColon, or Tab delimited. Below is an example of a Davis weather station day file:

If your date format begins with the day like dd/mm/yy as above then you will need to add a date format to the GetRealtime_setup.txt file base1 field like this: (If your date does not begin with dd and uses '/' and is in column 1 then nothing is needed.)

The Station_ID cell contains 'FILE-n' where n is the data column to write to the database. The Date is column 1, Time is column 2, and so the first data column would be 3... etc. The number and content of the header lines is not used and can be what ever or none at all as long as the first non space character is not numeric.

The GetAccess HDB database table 'riste' below has the text file name in the 'parameter_code' and the 'station_id' is just 'FILE':

Cumulus from Sandaysoft documentation says it's monthly log file (Aug09log.txt) gets updated about every 10-minutes:

 http://wiki.sandaysoft.com/a/Monthly_log_files

So GetRealtime should be able to read their (;) or (,) delimited file as well... but remember the format is 'dd-mm-yy' or 'dd/mm/yy' and has to be added to the GetRealtime_setup.txt because of this screwy dating convention... just like Davis.

EasyWeather.dat file:

The EasyWeather data file has it's date in the 3rd column so the base1 cell in GetRealtime_setup.txt would look like this:  yyyy-mm-dd, 3

You may find that many of your weather data types are not listed below on the table of datatype_id's. You can select any datatype_id that suits your averaging/cumulation/total needs and then change the unit_name to what ever you would like.  You may need more than one site_id if you still need more datatype_id's or want to use the same datatype_id more than once.

END OF SOURCES

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5)      You are now ready to add your new station name and data type to the table Rsite, but first you will need to determine the new station’s Site_id and Datatype_id.  These 2 values will then be used to create a unique Datatype_Site_ID that is stored with each retrieved value.

Site_Id's= 0^00 where 0=area or reach, 00=count in reach.  Site_Id's are 0 to 999.

Datatype_id 1= flow, cfs

Datatype_id 10= rainfall, inches, etc,… (See table of Datatype_id’s below)

Datatype_Site_ID (DSID) = 00^000 where 00=datatype_id and 000=Site_id.

Valid DSID’s are integers in the range -32,768 to 32,767

Example: DSID 10212 = rainfall, area 2, 12th station

Example: DSID 1212 = flow, area 2, 12th station

Example: DSID -1212 = Computed flow, area 2, 12th station

Use negative DSID's for values that are computed by GetRealtime.exe to keep them separated from the web source reported values and also to note it has been computed.

You might use another method for creating the Site_id and associated unique DSID but remember the valid DSID integer range -32,768 to 32,767.

Datatype_id’s are associated with formatting and averaging methods.  If  more than 32 (64 if negatives)datatypes are needed, then you can break up your station into 2 or more site_id's.

If you are retrieving metric values or converting English to Metric then it’s ok to change the unit_names to metric and for that matter even the datatype_name.  Just remember that datatype_id's have certain rounding and averaging methods.  Bearing this in mind, you could make your own data table with completely new parameters and units.  If anyone would like to share their alternative datatype_id table just add it to the comments button below or email me it and I will add it here. 

                        Table of datatype_id’s

USGS rounding means:

 0

 0.001 - 0.099

 0.01 - 0.99

 1.0 - 9.9

 10 - 999

 1010-999990

6)      Using GetAccess.exe, open the empty database file GetAccessHDB.mdb that has all the data in each table deleted.

7)      As an example we will add the Wunderground example above for Station ID = KLAS and Parameter Code = Dew PointF.  The Dew PointF associated datatype_id = 16.  Our first site_id will be area 1, station 1 or site_id = 101.  Our unique datatype_site_id = 16101.

8)      We are ready to update the table rsite with our new station data.  Click DB Tables.

Select rsite, and then check the Allow Edit check box click GO.  The blue * indicates the row is available for adding new data by typing in fields on that row.

.

Fill the fields as this example then click on the blue * and the data will be stored and a new edit line * added: (use alt-248 on num pad for ° degree symbol)

Let’s add the USGS station example for flow.  Site_id will be area 1, station 2 or 102.  Datatype_id for flow = 1.  The unique datatype_site_id is then 1102.  To add this data we can type at the blue * or we can copy a row from the ExampleRsite table using the Edit Menu button or right click on the selected and the Edit Menu will open.  For now just type in the new site data:

We now have 2 sites with the needed Station ID and Parameter Code for retrieving real-time data using GetRealtime.exe.  GetRealtime.exe stations list now needs revised with just these two new sites before data can be retrieved and stored.  Refer to the GetRealtime section below Adding sites to the GetRealtime station list.

Program Use

GetRealtime.exe

(retrieval and computations of real-time web data)

The hourly and daily data should be updated for the past 7 days using GetRealTime.exe so that the examples can be seen once you read this section on how to that.

Setting the Database Connection String:

If GetRealtime.exe cannot make a connection to the Access database the following message will appear.  Set the connection string to the GetAccessHDB.mdb database using the Connection button on the Select Station form (control button 6 below).

The connection string should look similar to this depending on the path where GetRealtime.exe was installed:

Driver={Microsoft Access Driver (*.mdb)};DBQ=

C:\Program Files\GetRealtime\GetAccessHDB.mdb;Uid=Admin;Pwd=Me;

Description of the controls on the GetRealtime form:

1)      Days—Number of days to retrieve.  1 day means yesterday and today.  The unit values are retrieved and averaged for hourly and daily values.  One daily value for yesterday will be available for storage.

2)      Missing Values Allowed in Day—Percentage of missing unit values allowed in a day before a daily average will not be computed.

3)      Bad Value Check—Percent change in the unit values from one time step to the next before the value is raised as a possible error.  If in batch mode, the value will be listed in the GetRealtime_errorlog.txt file.  If in interactive mode, a message box will appear for how to handle it.

4)      DSID for 1 Station—DatatypeSite_ID, typically not used but can be entered for 1 station retrieval.  Selecting just the 1 station from the station list is easier.

5)      Station Name or range—Displays the selected station or range of stations from the station list if only 1 station or a range of stations is wanted.

6)      Select Station From List button—Displays the station list if only one station is to be retrieved.  For editing the station list see GetRealtime.exe Setup Section above.

7)      Write Dailys—Daily average computed from the retrieved unit values will be stored in the database.

8)      Write Hourly Avg—Hourly average computed from the retrieved unit values will be stored in the database.  The hourly value time stamp will be for the end of the averaging period.  For instance, six 10-minute unit values with the last value reported as 10:04 am will have the hourly time stamp of 10:00 am.

9)      Write Daily MaxMin—Daily Max and Mins of the retrieved unit values will be stored in the database.

10)    Write Unit Values—Retrieved units value will be stored in the database.

Time steps for the unit values retrieved vary:

Wunderground unit time step can range from1-minute, 5-minute, on up to 3 or 4 hour time steps.  5 and 10-minute time steps are the most common.  Airports at Wunderground usually have 30-minute and 1-hour time steps.

The USGS data are typically in 15-minute time steps, but can vary during events.

CalDEC data time steps are 60-minutes.

USCS Snotel data time steps  are 60-minutes.

USBR data can be requested as either 15-minute or 60-minute.  Most USBR meteorological data time steps are available only as 60-minute.

CIMS data time steps are 60-minutes.

11)    Write Unit Shifts—Each shift value and the equation number used will be stored in the database for checking and debugging computation equations if any.

12)    Overwrite Source 5—Each daily, hourly, unit value has a Source field value stored. 1=Wunderground, 2=USGS, 3=CalDEC, 4=USCS Snotel, 5=WRITE PROTECT, 6=USBR, 7=COE, 8=CIMIS.  The database field Source if set to 5 by editing of the database will protect the value from being over written.

13)    Bad Value Check—Check for possible bad values as defined by the Bad Value Check percentage change.

14)    Reset Error Log File—Erase the file GetRealtime_errorlog.txt file located in the application path.

15)    Scheduled Batch—GetRealtime.exe can be run in the background at user defined intervals.  The Wunderground stations will always be retrieved at the interval set.  The other sources only update their data each hour so GetRealtime.exe will only query their stations at half hour intervals.  The first time GetRealtime.exe is run in batch mode all stations will be retrieved for the number of days set.  After the first time, only values for the current day will be retrieved.

Getrealtime.exe can also be ran in Batch Mode from a Desktop shortcut with the shortcut properties Target set as “…\GetRealtime.exe batch”.  Also GetRealtime.exe can be run from the Windows Control Panel’s Scheduled Tasks in the same manner, be sure to include “batch”.

16)    Start Realtime Retrieval button—Start retrieving data.  If the 1 station retrieval box is not checked, then all of the stations on the station list will be retrieved.

17)  Historical button—Retrieve unit values or daily values based on a user set date range instead of the number of days to retrieve.  The periods for the availability of historical unit values can vary for each source and each station.  The Historical Button can be toggled on and off by repeated pressing.

It's important that the MS Access HDB database be routinely 'Compacted and Repaired' to speed up downloads. The size of the MS Access database doesnt seem to matter as much as how often data is being updated. I retrieve about 100 stations every 1/2 hour with 5 minute unit values (Nexrad). I find the down load time will double in about 2 to 3 days so I 'Compact and Repair' using the GetAccess.exe 'Connection' button every day or two... so be smart like me. Look at your 'GetRealtime_errlog.txt' file to see how your download times vary over time.

My MS Access database is 200 MB's with about one years worth of data. Wikipedia says MS Access can handle 1 to 2 GB's. We shall see. One option to reduce the database size is save the database file every year and then delete all the unit values and keep going so historical unit values would be availble if ever really wanted in seperate files. 

Adding Sites to the GetRealtime Station List:

After you have deleted the example data from all the data base tables, then you need to delete all the sites on the GetRealtime station list as follows:

1)      Make a backup copy of the file GetRealtime_setup.txt for later reference, you will need it for reference!

2)      Open GetRealtime.exe and click on the Select Station from List button:

Click the Edit List button.  Right mouse click on the left column and the edit menu will appear.  Click Delete Record and the selected row will be deleted.  Continue row by row deleting all the records.  The last row can not be deleted, edit the last row then right mouse click the left column and Add New Record.  Edit the fields like this and click on Save:

Optionally, the setup file GetRealtime_setup.txt in the GetRealtime directory can be edited using Notepad provided with Windows in Start/All Programs/Accessories.

The stations on the list are now ready to be retrieved.

Make sure the DSID for 1 Station check box is not checked.  Click the Start Realtime Retrieval to test the changes to the station list and Access database changes.

The daily average values for yesterday were successfully computed and displayed indicating our changes to the GetRealtime Station List and the Access database were successfully made. Woohoo!!!

If not, recheck the values in the database table Rsite and retry.  If still unsuccessful check the values on the Station List.  The datatype_site_id must match in both the rsite table and station list and the parameter_code and station_id in table Rsite must be valid for that web source.

Change the Days text box to 7 days and repeat the retrieval so GetGraphs can graph the new data.  The final step is to edit the GetGraphs setup to display our 2 new sites.  If you open GetGraphs now you will see only the Web pages will have data.

See Adding Sites to the GetGraphs Setup below.

Computation Examples on the GetRealtime Station List:

The GetRealtime Station List has fields for adding up to 5 sets formula expressions, shifts, and bases.  The base of the equation is a value or expression that is evaluated to determine which formula expression will be used.  The shift is available to make changing the equation simpler by including the variable Shift in the equation.

The P1, P2, P3… variables represent the retrieved parameters in the order they were entered in the GetAccess database table Rsite Parameter Code field.

The variable D represents the DateTime value retrieved with the parameters.

The function Julian (D) returns the julian integer day of the year.

Example of converting Gage Height to Elevation:

05054000; -3710; Elevation; Red River Of The North at Fargo; 0; 0; P1+861.8

Notice the Datatype_Site_ID -3710 is a negative integer to keep calculated values separate from reported values and to point out it was computed.

In the above example the Base1=0 will convert any Gage Height below 0 as 0.

The Shift1=0 is not used.

The Formula1 P1+861.8 adds 861.8 to the retrieved Gage Height and is stored in the database.  The Gage Height retrieved is discarded.

Example of converting Temperature C to Temperature F:

09380000; -7510; Temperature; Colorado R at Lees Ferry; 0; 0; 32+P1*9/5

Base1=0 will convert any retrieved Temp C below 0 to 0 F.  Probably not a good example but ok for this stations water temperature.

Shift1 not used.

Formula1 32+P1*9/5 converts the retrieved Temp C to  Temp F.

Example of converting Temperature C to Temperature F with Shift:

05054000; -7710; Temperature; Red River Of The North at Fargo; -20; 0.5; 32+P1*9/5+shift

Base1=0 will convert any retrieved Temp C below -20 to 0 F.

Shift1=0.5

Formula1 32+P1*9/5+shift converts the retrieved Temp C to  Temp F and increases the value by 0.5 degrees F.

Example of converting Temperature & Dissolved Oxygen to Percent Saturation:

14211010; -13910; Dissolved Oxygen; Clackamas River near Oregon City, Or; 0; 1.015; 100*P2/(shift*(14.55-0.3940*P1+0.00718*P1^2-0.0000611*P1^3))

Base1=0 will convert any P1=TempC retrieved value below 0C  to 0% saturation.

Shift=1.015 is the adjustment for station elevation and is computed as Shift= 0.0000364*ELV+0.000000000563*ELV^2

Formula1=100*P2/(shift*(14.55-0.3940*P1+0.00718*P1^2-0.0000611*P1^3))

Where P1 and P2 represent the Parameter Codes in order in the database Rsite table of:

10,300 where P1=10= water temperature °C and P2=300=D.O. mg/l.

The dissolved oxygen saturation formula example above is a curve fit to USGS Weiss table at 760 mmHg or sea level.

Example of converting Gage Height to Flow:

09419800; -1013; Flow; Las Vegas Wash above Lake Mead;

3.9; .05; 401.8*(P1+shift-3.9)^1.502; D<cdate("2008-11-26"); int(100*(.05+(.10-.05)*(cdate("2008-11-26")-int(D))/(cdate("2008-11-26")-cdate("2008-11-01")))+.5)/100; 401.8*(P1+shift-3.9)^1.502; 4.7; 0.10-0.10*(P1-4.7)/(4.8-4.7); 401.8*(P1+shift-3.9)^1.502; 4.8; +0.00; 602.2*(P1+shift-3.9)^1.502

This conversion uses 4 sets of bases, shifts, and formulas.  Beginning with set 4:

Set 4=  4.8; +0.00; 602.2*(P1+shift-3.9)^1.502

Base4=4.8, should the Gage Height P1 be greater than 4.8 ft the associated shift and formula will be used.

Set 3=  4.7; 0.10-0.10*(P1-4.7)/(4.8-4.7); 401.8*(P1+shift-3.9)^1.502;

Base3=4.7 feet.  Should P1 gage height be >=4.7 ft and <4.8 ft the associated shift and formula will be used.

Shift3= 0.10-0.10*(P1-4.7)/(4.8-4.7) is shifting with stage where the shift will evaluate to 0.10 ft at P1=4.7 ft to 0 ft at P1=4.8 ft.

Formula3=401.8*(P1+shift-3.9)^1.502

Set 2= D<cdate("2008-11-26"); int(100*(.05+(.10-.05)*(cdate("2008-11-26")-int(D))/(cdate("2008-11-26")-cdate("2008-11-01")))+.5)/100; 401.8*(P1+shift-3.9)^1.502;

Base2= D<cdate("2008-11-26").  Should P1 gage height be <4.7 ft and then Base 2 is evaluated.  If the retrieved DateTime<2008-11-26 00:00 AM then the associated shift and formula will be used.

Shift2=  int(100*(.05+(.10-.05)*(cdate("2008-11-26")-int(D))/(cdate("2008-11-26")-cdate("2008-11-01")))+.5)/100 is shifting with time where the shift will evaluate to 0.10 ft on D=Nov 1 decrease to 0.05 ft on D= Nov 26.

Formula2=401.8*(P1+shift-3.9)^1.502

Set1=  3.9; .05; 401.8*(P1+shift-3.9)^1.502;

Base1=3.9 should the Gage Height P1 be less than 4.7 ft and D is greater than Nov 26 then the associated shift and formula will be used.  If the Gage Height P1 is less than 3.9 ft then the computed flow will be 0 cfs.

Shift1= .05

Formula1= 401.8*(P1+shift-3.9)^1.502

Note:  Turn ON the “Write Unit Shifts” on the GetRealtime retrieval to see what shifts are being computed and what formula is being used in the computation.

Example of converting Gate Opening to Flow:

09429000; -1310; Flow; Palo Verde Canal near Blythe, Ca; 81.0; 0.00; 3.17*70*(P1+shift-40.15)^1.5; P2>81; -0.00; 3.17*70*(P1+shift-P2)^1.5; P1>(P3+77); 0; 0.6214*70*P3*(64.32*(P1+shift-P2))^.51

This computation uses 3 sets of bases, shifts, and formulas depending on the flow type as submerged flow, submerged weir, free flowing weir.  Beginning with set 3:

Set 3= P1>(P3+77); 0; 0.6214*70*P3*(64.32*(P1+shift-P2))^.51

Base3= P1>(P3+77) where P1=upstream GH, P3=gate opening.  If Base3 evaluates true, then submerged orifice flow will be used.

Shift3=0

Formula3=0.6214*70*P3*(64.32*(P1+shift-P2))^.51 submerged flow equation.

Set2= P2>81; -0.00; 3.17*70*(P1+shift-P2)^1.5;

Base2= P2>81 where P2=downstream GH and 81 is the elev of the bottom of the gate for submerged weir flow.

Shift2=-0.00.

Formula2=3.17*70*(P1+shift-P2)^1.5 where P1= upstream GH and P2 = downstream GH.

Set1= 81.0; 0.00; 3.17*70*(P1+shift-40.15)^1.5

Base1=81.0 or if P1>81.0 then use free weir flow formula1 else zero flow.

Shift1= 0.00

Formula1= 3.17*70*(P1+shift-40.15)^1.5 where P1=upstream GH.

Example of Computing Evapotranspiration Reference ET with out Solar:

Computation of reference ET is done internally by GetRealtime using methods recommended by the ASCE standard Penman Monteith at an hourly time step.  Both the tall (alfalfa) and short (grass) computations can be made.  If you are interested in the ASCE methods, the following url will get you started:

http://www.kimberly.uidaho.edu/water/asceewri/ASCE_Standardized_Ref_ET_Eqn_Phoenix2000.pdf

The solar radiation used in the PM equations is computed internally using regressions of hourly Solar Radiation versus Temperature, Humidity, Zenith Angle, and Elevation in different regions of California.  The hourly regressions for a year have R^2 of 0.92 and a standard error of 160 Langley’s/day for the hourly time step.

MOVRC1; -27407; ET Grass; Bishop, Ca Wunderground; 0; 37.384,-118.422,-120,4183,0.75; P4

Base1=0 is not used.

Shift1= 37.384,-118.422,-120,4183,0.75 is made up of 5 parameters separated with a comma that describe the site and are:

1)      Site Latitude=37.384

2)      Site Longitude=-118.422 and is negative for longitude west.

3)      Standard Time Meridian=-120 and is negative for longitude west.  Pacific Time=-120, Mountain Time=-105, Central Time=-90, Eastern Time=-75.

4)      Site Elevation in feet= 4183 feet.

5)      Windspeed adjustment=0.75.  Windspeed used in the PM computations are to be at the 2 meter height.  Standard weather stations make their Windspeed measurements at the 10 meter height so the adjustment for 10 to 2 meter is 0.75.  Wunderground weather stations at airports and Madis stations should use the 0.75 adjustment.  An airport has a Station_ID beginning with K and is 4 letters long.  Madis stations begin with the letter M….  All other stations should use the windspeed adjustment = 1.  The difference between using 1 or 0.75 will normally result in about a 5% difference in ET.

Formula1= P4.  The Parameter_Codes in the database table Rsite is entered in this order:

TemperatureF,Humidity,WindSpeedMPH,ETshort

ETshort is used to compute a grass ETo, ETtall is used to compute an alfalfa ETo.

Example of Computing Evapotranspiration Reference ET with Solar Radiation:

If the weather station reports reliable solar radiation then the reference ET computation can be improved on low solar radiation days by using the reported solar radiation as follows:

MOVRC1; 27407; ET Grass; Bishop, Ca Wunderground; 0; 37.384,-118.422,-120

,4183,0.75; P5 

…note positive DSID of 27407 to distinguish if from the computation at this site with out solar radiation above.

The Shift1 and Base1 are same as above without solar radiation example.

Formula1= P5 (different than P4).  The Parameter_Codes in the database table Rsite is entered in this order:

TemperatureF,Humidity,WindSpeedMPH,SolarRadiationWatts/m^2,ETshort

Example of Computing Solar Radiation (for Longwave Radiation see SnowMelt below):

Solar radiation is computed internally using regressions of hourly Solar Radiation versus Temperature, Humidity, Zenith Angle, and Elevation in different regions of California.  The hourly regressions for a year have R^2 of 0.92 and a standard error of 160 Langley’s/day for the hourly time step.

KCAHELEN4; -29408; Solar Radiation; Helendale, Ca Wunderground; 0; 34.775,-117.330,-120,2470; P3

Base1=0 is not used.

Shift1=34.775,-117.330,-120,2470 is made up of 4 parameters separated with a comma that describe the site and are:

1)      Site Latitude=34.775.

2)      Site Longitude=-117.330 and is negative for longitude west.

3)      Standard Time Meridian=-120 and is negative for longitude west.  Pacific Time=-120, Mountain Time=-105, Central Time=-90, Eastern Time=-75.

4)      Site Elevation in feet= 2470 feet.

Formula1=P3.

The Parameter_Codes in the database table Rsite is entered in this order:

TemperatureF,Humidity,Solar

Computation of Wind Direction:

Wind direction is retrieved as either text directions such as NNW or in degrees such as 270.  Both are converted internally to a value between 0 to 4 step 0.25 where 0 and 4 both equal direction North, 1=East, 2=South, 3=West, 0.25=NNE, 0.5=NE, 0.75=ENE etc.

Hourly averages and daily averages are computed from the retrieved vectors and weighted with the Wind Speed if available as:

Avg Wind Direction = ATAN2(sum cos*speed, sum sin*speed)

Computation from Database Values (version 2.2.2):

Computations from database values retrieved and stored can be performed in real-time by using the Station ID = COMPUTE-Unit, COMPUTE-Hour, or COMPUTE-Day. For example, to average 3 Wunderground rainfall stations the GetRealtime_setup.txt line could read:

COMPUTE-Hour; 10035; Rainfall; Average Las Vegas Rainfall; 0; 0; (P1+P2+P3)/3

Remember to place the COMPUTE setup line BELOW the stations you will be computing values from.

Hour was used here because Wunderground stations rarely have the same time steps in the unit values table. The GetAccess Rsite table could look like this where the Station_ID = COMPUTE and the Parameter_Code would have the Datatype_Site_Id's to be the P1, P2, and P3 values in your computation, 10030,10031,10032.

Also, for HDB computation for Solar, Long Radiation, and Evapotranspiration that require special internal GetRealtime subroutines here is an example GetReatime_setup.txt for them:

Look at the GetAccess table 'exampleRsite' for examples of setups for these computations from the database.

Likewise, to compute runoff from rainfall use Station_ID= COMPUTE-Unit like this:

COMPUTE-Unit; 30755; Runoff; Prairie Creek, Dallas, Tx; 0; 2,2.5,0.15,0.2,9.03; P1

The database table RSITE would have the Parameter_Code= 10753 and Station_Id= COMPUTE.

Program Use

GetGraphs.exe

(displaying the real-time data and web screens)

Setting the Database Connection String:

If GetGraphs.exe cannot make a connection to the Access database the following message will appear:

Notepad will automatically be loaded with the setup file GetGraphs_setup.txt.

The Database Connection String should look similar to this depending on the path where GetAccessHDB.mdb file was installed:

Driver={Microsoft Access Driver (*.mdb)};DBQ=

C:\Program Files\GetRealtime\GetAccessHDB.mdb;Uid=Admin;Pwd=Me;

After connecting and loading the real-time data and web screens, then left mouse click on any of the graphs to page through the 15 pages in the provided setup.  Right mouse click on a graph or web screen to bring up a menu for changing the appearance and setting properties of the graphs.

Most of the menu choices will be self evident. Watch Levels and Setup are described below.

The Watch Level example was used to set the Humidity, % Saturation levels that should they be exceeded in the past 24 hours the graph title will start blinking.

The setup menu is used to add and delete pages, graphs, and web screens.

The Datatype_Site_ID for a graph can be scrolled though for any of the data in the GetAccess database.  The Datatype_Site_ID should be left blank when adding a web screen.  A DSID of -1 will be added automatically if blank and a web screen address is assumed for the Station Name.

Changes made to the setup will not be made permanent until Save all to GetGraphs_setup.txt is selected or prompted when quitting.  To quit, simply close the current page screen.

Adding Sites to the GetGraphs Setup:

If  you have deleted and added the two new data sites to the GetAccess data base and GetRealtime Station List then you are ready to delete all the example graphs and web screens in the GetGraphs setup file GetGraphs_setup.txt.  Make a copy of the GetGraphs_setup.txt file for reference if needed later.

Use the right mouse click on a screen to bring up a menu and select Setup, then select Delete Current Page and click Ok.

Continue deleting all pages.

Then use the Setup menu Add to Current Page to add the two new sites that were added to the GetAccess database and GetRealtime Station List examples above.

Use the Setup menu Save all to GetGraphs_setup.txt to save the setup for the 2 new sites.

Now that you are familiar with the steps involved in adding new sites the 3 programs GetAcess, GetRealtime, and GetGraphs you may repeat the process with your sites of interest.

Working with Web Screens:

Web Screens are added using the Setup Menu shown above.  The Datatype_Site_ID and Parameter Name should be left blank and the Web Screen URL address entered in the Station Name text box. 

Web Screen Example:

http://waterdata.usgs.gov/nwis/rt

Enter the above example URL into your web browser and this screen is will appear:

The above URL or the same URL taken from the web browser address box could be used in the GetGraphs Setup Menu Station Name text box.

If just the US map picture is wanted, then the scroll bars in the GetGraphs display can be used to center the US map…. Or a better method is to get the URL of just the US Map gif by right mouse clicking the US map in your web browser.  A menu will appear and the Properties can be selected to display the URL Address of just the US map gif:

The gif URL is: http://waterdata.usgs.gov/nwisweb/icons/waterwatch/images/real/us/real.gif

Web Screens can also be files on disk such as pictures or text where the URL is the filename such as C:\mydata\myfile.jpg or C:\mydata\myfile.txt.

When working with web screens it is best NOT to turn on the Setup check box "Allow navigation for this site" if not needed. If it is on then you will need to use the right mouse click menu to turn the page of your web screen. You may also note some web content reacts differently to mouse clicks. When using the right mouse click be sure to take note if it appears. It is sometimes hard to notice in full screen mode.

If you want your web screens to be refreshed at regular intervals like ever 5 or 10 minutes you must have GetRealtime.exe running as a scheduled task downloading at least 1 data site such as a Wunderground temperture. You do not need to include the real-time data graph. Also, Auto Paging must be turned on.

Update 5/6/09—Getrealtime.exe version 1.0.3 has een updated to compute real-time rainfall-runoff from the Wunderground or the other supported rainfall real-time sources.  Below is an example of editing the HDB database table Rsite using GetAccess.exe.  The datatype_id for runoff is 30.

GetRealtime.exe uses the SCS triangular unit hydrograph. Rainfall loss methods are initial loss, constant loss, and percent of basin impervious. The Getrealtime.exe setup file is edited using GetReatime.exe as shown below and as follows

Base1=0.

Shift 1 contains 5 parameters separated by commas, in this case 1, 0.25, 0.13, 5, 99.3.

These values are as follows:

1.0 is the basin Lag time in hours.

0.25 is the Initial Loss in inches. (Note: 

0.13 is the Constant Loss in inches/hour.

5 is the Percent of Basin Impervious.

99.3 is the Basin Area in square miles.  

(Optionally, the SCS triangler unit graph recession ratio may be added and defaults to 1.67 if not included.)

(Also, the rate factor at which the initial loss recovers may be added and defaults to 0.2 if not included.)

Note: For SCS Curve Number equivelants try 0.2 constant loss and vary the intial loss using GetMapArea.

Formula1 contains the resulting runoff as P1.

If there is no rainfall the Initial Loss will begin being reset at the rate of 0.2*Constant Loss. In this case the Initial Loss will have returned to it's initial value of 0.25 after 9.6 hours.

If there is rainfall the computed and stored runoff will be carried out to the peak discharge. GetGraphs.exe can then display the predicted future runoff hydrograph up to the peak flow that the rainfall up to the last retrieval has produced.  If the computed peak flow will be occurring on a future day like tomorrow because of a large lag time, then that future peak value will be shown as the midnight value of the current day. This way GetGraphs.exe will be able to at least plot what the future peak will be.

For basins having significant indirect runoff and need better definition of the recession then you may optionally add 2 additional coefficients to describe the recession in addition to Tp/Tr ratio (1.67). Here is an example of a GetRealtime setup data line for an extended recession.

NEXRAD-DAX; 30425; Runoff; Big Cr nr Groveland, Ca W/adj Rain; 0; 8,0.55,0.10,1.0,16.3,1.67,0.2,0.3,3; P1

Where:

8=basin lag time, hours

0.55=initial abstraction, inches

0.10=constant loss rate, inches/hour

1.0=percent inpervious, %

16.3=basin area, sq.miles

------optional Tr/Tp and recession values-----

1.67=Tr/Tp

0.2=initial loss recovery rate factor. Recovery rate will be 0.2 * contstant loss rate

0.3=fraction of rain excess applied to recession and removed from peak

3=factor used to multiply Tr by

------- 2nd Optional Seepage factors for a base flow (NOT SHOWN)-----

0.2=fraction of rain excess applied to recession and removed from peak

10=factor used to multiply Tr by

As shown in the figure below, version 2.0.1 now has the optional recession Tp located at the same time of the peak triangle. I made this method up and I think it works great... besides I could not figure out what a gamma function is.  The optional recession can allow the recession to receed for days if needed.

You may wish to use the free GetMapArea (More Stuff) to quickly evaluate the effects of  lag, losses, and percent impervious, especially if  your rainfall gage has a recording streamflow gage for calibration of the rainfall record.  Calibrating actual runoff is most educational ... just find a USGS streamflow gage and use Wunderground's Wundermap to see if a rain gage is available for honing your runoff skills using GetMapArea's storm file and hydrograph  reading abilities. 

Again another set of 2 optional seepage factors may be entered to simulate a long receeding base flow. Adding either of these 2 optional flows, interflow and base flow, will create the same runoff volume as would be computed without them. The future extended days recessions will be truncated when written to the HDB database. This means if you want to keep a running base flow going you need to set the retrival 'Days' to cover your recession period. You may wish to create a seperate folder to run another copy of GetRealtime.exe from for this purpose.

Video how to for determining triangular unit graph coefficients:

Simulate SCS Curve Number Loss and add coefficients to Setup file and Database :

Note: For SCS Curve Number equivelants try 0.2 constant loss and vary the intial loss using GetMapArea.

Update 5/17/09—  Getrealtime version 1.1.0 has updated GetGraphs.exe to include hydrograph routing and combining of flow graphs.  The routing is perfomed using Tatum’s Travel Time or Lag.  (GetGraphs 1.2.0 now also includes Modified Puls routing, see below.)  Two displayed graphs can be routed and combined and also may be combined with database flow data as follows:

Right mouse click the existing graph that you wish to use for displaying the routed graph.  From the menu select “Set Routing”.  To route a graph that is already displayed before the current graph, fill out the text fields as shown below:

Graph1 to be routed is on the current Page 2 and is Graph number 1.  The Tatum Travel Time is 2.5 hours.  Press Ok and the current graph will show the routed hydrograph of Graph1, Page 2.  Remember that the graph to be routed must be located  before the current graph.  Graphs are numbered from left to right starting with 1.  If you select Graph 6 as the graph to contain the resulting routing, then only graphs 1 through 5 can be used for routing or any graph on earlier pages.

To combine 2 graphs, follow this example:

The above example will route Graph 1 with a lag time of 2.5 hours and then combine with Graph 3 that is not routed (zero lag time).

To route a graph and combine with a station flow in the database follow this example:

The above example will route Graph 1 with lag time of 2.5 hours and then combined with database flow values for station Datatype Site ID (DSID) = 1211.  The station data is not routed.  GetRealtime.exe will now route and store the flows in the HDB Access database (See bottom of this web page).

Update 5/26/09—Getrealtime version 1.2.0 has updated GetGraphs.exe to include hydrograph routing using the Modified Puls method.  Below is a Tab delimited ModPul file example that was cut and pasted into Notepad from Excel.  The ModPul file may also be comma delimted or fixed width of 9 spaces.  The data lines consist of one title line, the next is the number of lines of Elev, Flow (cfs), and Stoarge (acre-feet).  (Elev is not used.)  The Notepad file is saved as a text file with any file extention.  My example is the text file Dallas.rat.

 

The Modified Puls routing is selected as described above for Tatum’s method, only the Lag is set to zero and the ModPul rating filename is entered as shown below:

 

See the More Stuff page to download ChannelStorage.exe to automate the creation of the trapezoid channel ModPul rating file used by GetGraphs.exe and GetMapArea.exe.

 

 

Update 6/9/09—Getrealtime.exe version 1.3.2 has been updated with computation of average area rainfall amounts using NOAA's WSR-88D radar imagery .  These images are provided free on the web and are updated about every 5 minutes.  The NCR files have been relocated. You will need the latest version of GetRealtime.exe 1.3.2. as of 6/9/09.  You may down load just the GetRealtime.exe here and replace the old version in your C:\Program Files\GetRealtime directory.  Requires display with 32-bit colors.

 

 

So what you may say?!!  Well, listen up and learn…

 

Traditional area average rainfall is obtained by rainfall gages located in or near the area of interest and averaging the rain gage amounts using many methods.  If you’re lucky you might find a rain gage nearby or you would have to install and maintain a network or rain gages yourself.   The tools presented here will allow you to create point rainfall rates ANYWHERE in the USA and greatly improve area averaged amounts and best of all IT’S FREE!!!

 

What use can I make of this you may ask?!! 

 

1)—Getrealtime can convert the average area rainfall to runoff and route and combine with other areas to generate a flow record at any point in the USA in real time (uh, maybe).

 

2)—If you’re an agricultural irrigation district and dress like one or even a small farmer that don't, then you can outline your district boundary and compute the 5-minute, hourly, and daily averaged rainfall on your district and adjust your water order accordingly in real time with out the cost of maintaining a network of rain gages.  Combine this with Getrealtime’s Penman-Monteith standard evapotranspiration computation and you are in like Flint.

 

3)—How about Local, County, and Federal fire fighters wanting to maintain a record of recent rainfall of small to large regions for estimating fire hazard potential in real time.

 

4)—Or anyone wanting to maintain a real time rainfall record for anywhere in the USA for what ever reason.

 

To do this you will need 2 new text files for your area of interest, a boundary file and a point file.  The steps for generating these 2 files are outlined here:

 

www.GetMyRealtime.com/GetNexradHelp.aspx

 

You will have to download and install GetNexrad.exe separately from your GetRealtime download.

 

As noted the file naming convention used by GetRealtime is crucial.  These two file names consist of the file type, radar site id, and datatype_site_id.  For example the radar site id is ESX and the DSID is 10215.  The radar site id is displayed on the radar image screen in the center of the radar site navigation arrows.

 

Boundary File Name Example:  NexradBoundaryESX10215.txt

 

Point File Name Example:  NexradPointESX10215.txt

 

These 2 files are placed in your Getrealtime file directory.

 

Once you have generated these two files then you have to add site information to the GetAccess HDB database and to the GetRealtime setup file.

 

Here is an example of the data required in the GetAccess HDB table Rsite for both runoff (30) and rainfall (10):

 

 

The new crucial information is in fields Parameter_Code and Station_ID.  The Parameter code is the type of radar image being used, either 1-Hour Total code=N1P, Base Reflectivity code=N0R or Composite Reflectivity code=NCR.  NCR seems to be updated more consistently during storm events than N0R but I may be wrong.  1-Hour Total seems preferable anyway.  And N0R is spelled with a zero.  I'm beginning to like the N0R more and more.  I have only been at this for a week.

 

The N1P 1-Hour Total radar images ARE NO LONGER treated differently than N0R and NCR rates. If the GetAccess HDB database has accumulated more than 1 hour of unit values then the interval rainfall amount is computed as RadarNow-(RadarLag1-UnitValueLag60&Interval) else it is simply RadarNow/(60/interval).  I may be on a fool's errand trying to sample an irregular radar time series at a regular interval with lag.  We shall see.  Note: Getrealtime.exe 1.3.9 updated 12/18/09 now treats the N1P rainfall 1-Hour Total just like the N0R and NCR in/hr. It seems to make more sense, but tends to lag the rainfall over the hour.

 

Although Storm Total NTP images would avoid potential error in lag of the 1-Hour Total, their resolution seems to be too grossly graduated at the lower values to be much use for farmers and fire hazards in the West and for runoff from small basins, but I may be wrong again. I will add Storm Total soon for those living in swamps and other backwaters so check back often.

 

I have updated Getrealtime to let users put there own DBZs to rainfall rates in the setup SHIFT cell like this:

 

NEXRAD-AMX; 10915; Rainfall; Ft Lauderdale N0r; 0;  0.00, 0.00,.02,.04,.09,.21,1,2,4

 (dont forget that 0 goes in the BASE cell or other limiting value and the first dbz=10 to change)

 

Note that not all the upper rates are needed if not revised. I have updated GetNerad.exe to allow users to change the rainfall rates in the same manner by including the optional file 'Dbz2Rainrate.txt' that has just the one line that looks likes this:

  0.00, 0.00,.02,.04,.09,.21,1,2,4

 

More help examples are available at http://getmyrealtime.com/RainfallComparisons.aspx and http://getmyrealtime.com/SierraSnowfallComparisons.aspx.

  

 

 

The Station_ID in this example is NEXRAD-ESX which tells Getrealtime to use the ESX site radar for imagery acquisition.

 

You might notice that new datatype_id that must be used for Runoff computation is 30 and the datatype_id for rainfall is still the old 10.

 

Here is an example of the data required in the Getrealtime setup file GetRealtime_setup.txt for both runoff (30) and rainfall (10):

 

 

Notice first that the Rainfall for a station is retrieved before the runoff can be computed and so is placed before it in the setup file.  Again the Station_ID in our example is NEXRAD-ESX.

 

Or... version 2.0.1 can now use Station_ID= COMPUTE-Unit like this:

COMPUTE-Unit; 30755; Runoff; Prairie Creek, Dallas, Tx; 0; 2,2.5,0.15,0.2,9.03; P1

 

The HDB database table RSITE would have the Parameter_Code= 10753 and Station_Id= COMPUTE.

 

If your site of interest is too near the radar site and causes false background readings then you can put a lower bound on the radar rainfall values being recorded by entering a shift1 and formula like this:

 

 

Something ***NEW 7/4/2009*** on the GetRealtime menu at start up is the check box on the right for ‘Get Past Radars’.

 

 

If the ‘Get Past Radars’ box is checked at start up then images available for the past 4 hours will be retrieved and processed (24 images in clear mode, 48 rain mode). Otherwise GetRealtime only retrieve the latest image at the time intervals you desire. This means GetRealtime must be run in Batch Mode as described above at a regular interval of 5 or 10 minutes. The easiest batch mode method is to check the checkbox ‘Scheduled Batch’ and GetRealtime will go to sleep between retrievals.  If the batch interval is set to 5 minutes or more and the 'Get Past Radars' is checked then up to all 4 hours of past radars will be retrieved. 

 

If there is rainfall the computed and stored runoff will be carried out to the peak discharge. GetGraphs.exe can then display the predicted future runoff hydrograph up to the peak flow that the rainfall up to the last retrieval has produced.

 

 

Does This Radar Stuff Really Work???

 

 Let's compare with an actual point rainfall gage. (This better pan out well is all I know)

 

Example of how to create a Boundary File and a Point file for a 1-Point Wunderground weather station comparison. As above, create a boundary file for a very small area around the weather station location. Only the column of X,Y pairs matters. From here knowing the center coordinates hand edit the XY boundary by hand similar to this (any size is ok):

 

Edit boundary for a better square Area1 X,Y Coordinates (pix)

322, 188

322, 190

324, 190

324, 188

322, 188

Xmin 322, Ymin 188, Xmax 324, Ymax 190

Centroid= 323, 189

 

Now you can use Notepad to create this simple Point file:

 

323,189,323,189

1

 

That's it, just 2 lines. The reason for creating a larger area boundary file is so you can see it on the computer screen and can click on the color within it. The Point file does all the work.

 

The utility program LatLongPixels has been added to more accurately determine the point file value needed given the points Lat/Long values. Wundergrounds weather stations all have their Lat/Longs on their station location screen on the right side of their current daily history pages (the pages with the 'comma delimited download' option. You may download this utility here.

 

I am using these 2 file examples for the Miami AMX radar to compare with the Wunderground weather station KFLCORAL5 west of Fort Lauderdale, Florida. Why this paticular station? Because it was somewhat near a highway intersection for locating on the radar image and appears to be well maintained. How would I know? Because I can read maps and also wind speed is a dead give away. The least amount of calm is golden. But most of all, you want some rain to be recorded when it is raining, duh. And the last thing, but minor, is time step. I really like 10-minute and 5 minute time steps that appear regular but it's not critical.  Wunderground stations can be jewels or really bad losers so check them out. I will try to post some data on this Nexrad vs Wunderground example soon... if it works out favorably, otherwise I'm burying it. ;-)

 

For the results of these rainfall comparisons go here.

For an example of how to automate GetRealtime Nexrad radar-runoff and the results of these rainfall-runoff comparisons go here.

 

 

GetRealtime 1.5 updated 1/2/2010 will now route and combine runoff and flow hydrograph values in the GetAccess database. To do this start with GetAccess.exe, select DB Tables, Rsite, and add a new line like this:

 

 

The new parameters are Parameter_code and Station_id.

 

Rsite table setup in GetAccessHDB.mdb Access database:

DSID=1xxx

DataType_ID=1

Datatype_name=flow,....

Parameter_code=FlamingoRoutingFile.txt <<< your routing control file name

Station_id=ROUTE

 

Now set up GetRealtime.exe's GetRealtime_setup.txt file like this:

 

Station_ID; DatatypeSiteID; Parameter; Site_Name;

ROUTE; 1214; Flow; Routed Flamingo Wash at Nellis Blvd Flows

 

Place the routing below any of the retievals or runoff computations in the setup that will be routed.

 

Now all we need is to create the routing control file. The control file consists of the 5 commands:

 

GET (gets flow values from GetAccess HDB database)

COMBINE (adds the current two hydrographs)

SUBTRACT  0 or 1 (subtracts the current two hydrographs, a 1 value reverses order)

ROUTE (routes the current hydrograph using Tatum, Modpul, or Muskingum)

END (end and write current hydrograph to HDB database)

 

As an example text file named FlamingoRoutingFile.txt:

 

Your Title Line Here is a must.

GET 4 30752 Upper sub Praire Cr (30752 is the DatatypeSite_ID for Sub Praire Cr)

GET 4 30753 Lower sub Praire Cr (4 indiates unit values, 3=hour, 2=day)

COMBINE

ROUTE Tatum 2.5   travel time in hours

GET 4 1754 Trib sub dallas river

COMBINE

ROUTE Muskingum 2 0.25   lag in hours and X=.25 in who knows.

GET 4 1758 Little sub trib

COMBINE

GET 4 1757 Left fork sub trib

COMBINE

ROUTE Modpul Flamingo.Rat    you can put comments at the end of each line

END

(Any notes after the END command will be ignored)

 

 

Note that after the initial two GET's, there after every GET a COMBINE must follow.

 

Try out some routings by getting a USGS retrieval and on this one station try gettting, combining and routing.

 

If your basin has more than one main channel, then you will need to write a seperate control file for it and save each channel in the HDB database before combining with the last control file. Remember to try using my ChannelStorage.exe available here to create the Modified Puls rating.

 

 

GetRealtime 1.5.1 updated 3/18/2010  now supports NEXRAD Radar images for NVL (vertical integrated liquid), NET (echo tops), N0S (storm relative velocity) and N0V (base velolcity) as well as the N0R, NCR, and NTP rainfall conversions for the scientifacally minded. Although a screen area averaged NVL and NET make little sense, the maximum value on the radar screen can be used as an early warning for hail storms and other exciting things. To determine the maximum value on the the Nexrad radar image a new Datatype_ID has been added and is 32 to indicate a radar image maximum is wanted. See list of Datatype_ID's above. Remember valid SDID integers are -32,768 to 32,767 so your Site_ID is limited to 1 to 767 instead of 1 to 999.

 

Use GetAccess to set the HDB rsite table as follows:

Now add the site to GetRealtime_setup.txt using either Notepad or GetRealtime.exe itself like this:

 

Now we need a Boundary file to determine what points will be checked on the radar image. The boundary needs to cover the 143 mile radius around the radar site and so using Notepad the Boundary file will be a rectangle like this named NexradBoundaryAMX32001.txt:

 

Miami AMX Full Radar Area

10,15

10,534

589,534

589,15

10,15

Xmin 10, Ymin 15, Xmax 589, Ymax 534

Centroid= 299,274

  

Note that Ymin and Ymax can be shrunk at higher latitudes and you can trim some fat off the rectangle by adding 0.292 and 0.708 of the height and width for an octogon like this:

 

Miami Full Radar Octogonal Area

10,167

10,383

179,534

420,534

589,383

589,167

420,15

179,15

10,167

Xmin 10, Ymin 15, Xmax 589, Ymax 534

Centroid= 299,274

  

Lastly all that is needed is the Point file.  The Point file is created using GetNexrad.exe. Fire up GetNexrad.exe and select 'Create Point File' and select the Boundary file name located in the GetRealtime folder above like this:

Select 'Create File' and answer 'NO' when prompted 'Do you want to create a single point file?'.

  

The 580 x 450 boundary will contain 261,000 points in the point file. Luckily the pixel size for the radar NET and NVL data points is about 5 pixels by 5 pixels for the 2.5 x 2.5 mile coverage so only every 4th pixel needs to be checked reducing the actual work to 16,312 pixels... child's play. On the other hand if you want the maximum for a NCR image all 261,000 pixels will be checked... ouch!

  

The maximum N0S and N0V velocitys are checked every other pixel or about 1 mile apart. The storm relative velocity maximum difference is calculated as the differnce between non-zero values of oppisite signs (-inbound and +outbound velocitys) and can exceed the max 50 knotts and 99 knotts. Nearly all N0S images plain maximum velocity are near the maximum value of 50 knotts and so is of little use hence the difference calculation. Green next to Red, means your dead... or its birds and bats and business as usual... boy those guys at headquarters keep us hoppin..

 

We are all set to automate GetRealtime in batch mode as discussed above. You may wish to save radar gif images with maximum values above a certain value by checking the Save Radar box and be alerted by a beep by checking the Beep box. I normally run GetRealtime in batch mode like this:

  

The 'Delete Temporary Files' when checked will delete temporary internet files and history that Interet Explorer saves in it's temporary files location, BUT NOT any gif image files you wanted saved in the normal download location. Normally it is best to check this box.

 

The 'Other Program Friendly' when checked will pause to allow for other programs execution if needed with a smidgeon of reduced download speed.

 

The 'Use other nexrad server' when not checked will first try to use:

  http://radar.weather.gov

then if no connection...

  http://www.srh.noaa.gov

If checked the reverse order is performed. Infrequently at times one server will have the requested gif images and the other will not.

 

If a Gif file download is timed out, GetRealtime will try to down load the gif again before moving on.

 

  

Below is an Echo Tops NET radar image as shown by GetNexrad and the octogonal area maximum value 15 is shown in the window caption as well as the point I clicked on:

 

Here is an N0S max velocity diff exaample:

 

 

Radar gif images may be saved to file when values exceed the value entered in the 'Base' field as shown below and will over ride the value entered on the GetRealtime main screen when 'Save Radar' is checked. If the base value is below 0.01 it will be used to remove rainfall values that are caused by ground clutter as described above.

 

If you would like to save all the 32 datatype radar images at a site based on the first of a series being saved then enter '0' as 'base1' for the subsequent like this:

 

Note: NET and NVL have been discontinued.... "As part of troubleshooting some RIDGE delivery problems, we discontinued these two products as part of troubleshooting. The products will restart when RIDGE2, version2 is deployed. This is not likely until after the start of 2012." ~NWS ROC~ ...but are currently available on the Ridge2 Testbed below.

 

 

RIDGE 2 TESTBED

 

GetRealtime.exe has been updated to read the new 1000x1000 pixel PNG files available on the Ridige 2 Testbed. The new higher resolution DBZ product N0Q has 0.5 dbz resolution compared to the old 5 dbz resolution and should be your base reflectivity product of choice.

  

  

Your old boundary files can be upgraded to the new Ridge2 world files using GetNexrad.exe and is as simple as choosing the short range or long range N0Q product.

 

With the new N0Q 0.5 dbz resolution, the new file "Level2RGB.txt" allows on the fly choice of rainrate type conversion such as Convective 0, CoolWest 1, CoolEast 2, Tropical 3 and Semi-Tropical 4. To tell GetRealtime which rainrate conversion type to use simply put a 0, 1, 2, 3, or 4 in the GetRealtime setup file Base1 setup cell or leave blank for Convective.

 

In the GetAccess Database the new Parameter Code is the product code with "-Ridge2" attached like N0Q-Ridge2.

 

Remember Ridge2 is a Testbed and may change so if problems occur check back for updates to GetRealtime.exe.

 

For much more info on the Ridge2 products, see the GetNexrad Help web page.

 

 

Shifting Retrieved Times to Your Time Zone

  

Update 10/19/2011 allows GetRealtime retrievals to be adjust for any time value or time zone. The GetAccess 'rsite' table now has a field 'time_shift' which you can enter the hour shift. To adjust a Wunderground station in Florida (ET) to your home in California (PT) then you could enter a -3 for the 3 hour time zone difference in table rsite field 11 ('time_shift'). This makes comparing Nexrad radar stored in your time zone easier.  If you add this field 11 to your database table 'rsite' it is a double precision floating point.

  

 

 

  

Snowpack and Snow Melt (new with V2.2.1)

 

(Update 12/3/2011)

GetRealtime.exe 2.2.1 has been updated to compute a continous year around simulation of a point snowpack accumulation and melt. The melt (output as a rainfall parameter) can be input to Getrealtime's rainfall-runoff for a real-time continous simualation through out the year.  And yes, the snowmelt calculation will give the correct precip even in July... in Death Valley.

 

GetRealtime has adapted the methods of the physically based point snow surface hourly model ESCIMO (Energy balance Snow Cover Integrated MOdel) (Strasser et al., 2002) for hourly, 5-minute, or daily time steps for simulation of the energy balance, the water equivalent and melt rates of a snow cover. ESCIMO uses a 1-D, one-layer process model which assumes the snow cover to be a single and homogeneous pack, and which solves the energy and mass balance equations for the snow surface by applying simple parameterizations of the relevant processes... like I would know.... it's just science.

  

Example GetAccess 'rsite' table for snowpack:

 

The station_id SNOWMELT parameter_codes order must be strictly followed but the site_id part of these datatype_site_id's are up to you. I would assume you would want to use a Wunderground gage for these first five inputs but compute the output for another site_id meaning the last four datatype_id 's 10, 23, 11, and 31 can belong to your real point of interest. This example computes the snowpack for the Wundergage site but with Nexrad Radar precip so has a different input precip site_id.

 

In the station_id SNOWMELT output precip datatype_id code is 10 for rainfall, which I named rain/melt here and has the parameter_codes:

 

17411,18411,28411,29411,-29411,10400,-23411,-11411,-31411

Temp. 17

.....,Humidity 18

...........,Windspeed 28

.................,SolarRadiation 29

.......................,LongRadiation -29

..............................,Precip Input 10  (the output Rain/Melt is this whole rsite record)

....................................,Output SnowWaterContent -23

...........................................,Output SnowAge -11

..................................................,Output Albedo -31

 

Albedo output has been added because the starting value really cannot be calculated from just Snow Age because of it's variable recession coefficent history. And as it turns out, it seems pretty important so needs looked after.

  

 Example GetRealtime_setup.txt: 

Station_ID = Snowmelt-hour or Snowmelt-unit (yes, 5-minute snowmelt!)

 

The shift1 cell is used if you would like to adust the 6 input parameters above and the 7th adjustment is for Albedo decay rate (<1 to slow down ripening but this decay factor * (-0.12 or -0.05 ) only applies if snow age is greater than 7 days). You may leave shift1 blank or just add up through your parameter of interest. For example to add 3.5 degrees F to the Wunderground input only for a different elevation of interest, then only the first +3.5 is needed. I'm really not sure how one would adjust say Solar radiation for north or south exposure but you can change the multiplicitive factor 1 here following the strict parameter order above like +3.5, 1, 1, 0.8, 1, 2.1, 1.

 

On 2nd thought, if you change any of the first 3 (Temp, Humidity, Wind) for use at your real site of interest, then you will need to recompute Solar and Longwave Radiation, which can be done, but I need to make a Tempature change as painless as possible. Based on my regression formula at this elevation, a 3.5 F Temperature change would cause a 3.4% change in Longwave Radiation over the year or about 1% for each degree F.  This probably means that a 1000 ft elevation lapse rate of -3.5 F change should be nothing to worry about for radiation. I already have found the Longwave Radiation factor needs to be less than 0.5 in the Sierras to keep the current snowpack from completely melting.  (not to worry, see graph below)

 

Changing the input Precip is ok, ie., 2.0 for 2.0 times the N0Q radar precip at your site or drainage area of interest.  And if you add a '0' after the Albedo factor then the computation steps will be printed to the file 'SNOWMELT.txt' which you can paste/open with  Excel to read.  After the novelty wares off, remember to delete the 0.

 

Input Example GetRealtime_setup.txt:

KTRK; 17411; Temperature; Truckee, Ca Airport

KTRK; 18411; Humidity; Truckee, Ca Airport

KTRK; 28411; Wind Speed; Truckee, Ca Airport

KTRK; 29411; Solar Radiation; Truckee, Ca Airport; 0; 39.320,-120.140,-120,5900; P3 (*computed*)

KTRK; -29411; Long Radiation; Truckee, Ca Airport; 0; -4.55 (*computed -4.55F temp adj optional*)

KTRK; 10411; Precip; Truckee, Ca Airport

(Output)

SNOWMELT-hour; -10411,-23411; Precip,swc; Truckee, Ca Airport; 0; +0,1,1,1,1,1,1;

(note snow age datatype_id 11 and albedo 31 are also input/outputs as is snow water content 23 for start up.)

 

One thing to note is that unlike I would have thought, it is not sunshine that melts shiny new snow so much as the longwave infrared temperature of the clouds and humidity and what ever else is up there... those heat  fluxes... beyond the horizon of perception.  Ok, that is alot of scientific propaganda, everyone knows snow melts in the day. ;-)

  

The following comparison shows the snow water content computed hourly from two different Wundergages for Caples Lake at 8000 ft eleveation. Complete T, H, Wind, Solar, and Longwave was computed for both Wundergages.  The other adjustment factors were: -T..., 1,1,0.8,L,1.17,0.5

 

Dutch Flat, Ca: 3700 ft and 53 miles due north of Caples Lake, T adj= -10.4F , L adj= .45

Bear Valley, Ca: 7200 ft and 17 miles due south of Caples Lake, T adj= -2.7F, L adj= .35

 

  

  

  

It seems you should always adjust the Longwave Radiation factor or even the Solar factor. For example, with no record of snow water content but a web cam view of Fargo, I adjusted the Longwave factor to 0.7 to match the days on the web cam I saw snow on the ground before it melted in November 2011. Another factor that might have also helped in the Sierra's would be to try the Albedo decay factor. Or all of them. Google each input parameter's effect on snow melt and you will probably find a study that may give you something to go by... or trial an error it like me.

 

You have to be a little adjustable with this snow melt science I quess. Boy I wish I had paid more attention in school about this heat transfer stuff.... but hey, I live in the desert.  That is no excuse... the desert mountains are ripe with snow to come melting down on you sooner or later. The Virgin River floods of Utah in 2010 are a good example of the largest floods in the desert being from rain on snow.  So keep your lamps trimmed and burning. Use Nexrad and my snow melt to escape the diluvian to come. ;-)

  

Using Unit Values:

SNOWMELT-unit

 

When using Nexrad Radar 5-minute values only the period for actual precipiation events is needed. You do not need to keep the radar record going all the time. When the Nexrad 5-minute values are present the weather gage input Temp, Humidity, Wind, Solar, and Longwave are used at 5 minute time steps and output will be 5 minute time steps. When Nexrad 5-minute values are missing, zero precip is assumed and the output unit value time step will be the irratic time steps of the Wunderground gage inputs. Add a zero to the 8th shift1 cell factors as descriped above to see the full computations output for how this works.

 

Using Day Values:

SNOWMELT-day

 

Daily's seem to work also. You may want to investigate any changes to factor adjusments that would be needed if any.

  

Parameter values and constants used (updated 12-3-2011):

Parameter/constant  Symbol  Value  Unit

Soil heat flux B 2.0 Wm−2

Minimum albedo amin 0.50

Maximum albedo (amin+aadd) 0.90

Recession factor (T > 273.16 K) k -0.12  (32.0 F)

Recession factor (T < 273.16 K) k -0.05

Threshold snowfall for albedo reset 0.5 mm running sum for a day (0.02")

Threshold temperature for precipitation phase detection Tw 275.16 K (35.6 F)

Emissivity of snow 0.99

Specific heat of snow (at 0 C) css 2.10×103 J kg−1 K−1

Specific heat of water (at 5 C) csw 4.20×103 J kg−1 K−1

Melting heat of ice ci 3.337×105 J kg−1

Sublimation/resublimation heat of snow (at –5 C) ls 2.8355×106 J kg−1

Stefan-Boltzmann constant 5.67×10−8 Wm−2 K−4

and... just so you know I know, 1W/m-2 =2.065 Langleys/day... geez I hope.

 

Also see my ongoing snowfall study at:

Nexrad Snowfall Comparisons in western central Sierras, CA

 

 

 

That is all....

And again, it's important that the MS Access HDB database be routinely 'Compacted and Repaired' to speed up downloads. The size of the MS Access database doesnt seem to matter as much as how often data is being updated. I retrieve about 100 stations every 1/2 hour with 5 minute unit values (Nexrad). I find the down load time will double in about 2 to 3 days so I 'Compact and Repair' using the GetAccess.exe 'Connection' button every day or two... so be smart like me. Look at your 'GetRealtime_errlog.txt' file to see how your download times vary over time.

 

My MS Access database is 200 MB's with about one years worth of data. Wikipedia says MS Access 2003 can handle 2 GB's or 10 more years. We shall see. MS Access 2010 still uses our 2003 file format.  One option to reduce the database size is save the database file every year and then delete all the unit values and keep going so historical unit values would be availble if ever really wanted in seperate files. (as if Windows will never die, remember DOS)

 

And my term 'HDB' stands for something I aquired from a bygone era, Hydrologic Data Base. I should use the MS Access file name MDB... which stands for... MYHydrologic Data Base... or something.

 

Good luck … and with any luck…

Rainy days are here again!!!

END

 

 

Some additional page links about ET and Nexrad Radar help and comparisons:

List of How To Videos on Youtube
Help Page for GetNexrad.exe
Nexrad Rainfall to Tipping Bucket Comparison
ET and Radar Rainfall along the Lower Colorado River, AZ-CA
Nexrad Rainfall-Runoff Comparison Las Vegas Valley, NV
Nexrad Rainfall-Runoff Comparison San Jouqin Valley, CA
Nexrad Rainfall-Runoff Comparisons in northwestern Arizona
Nexrad Snowfall Comparisons in western central Sierras, CA


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