This file represents the most frequently asked questions as compiled
from user feedback, system demonstrations, and phone conversations regarding
the LDAD EMDS system. Please contact us at 303-497-6053, email
jwake@fsl.noaa.gov, if you have any comments or further questions.
A: LDAD or the Local Data Acquisition and Dissemination System is the component of AWIPS that facilitates the exchange of data between the NWS's Weather Forecast Office and you. The graphical form of LDAD's dissemination capability is the Emergency Management Decision Support (EMDS) system. It is a java applet/application that displays AWIPS weather information in a highly graphical, multi-windowed, multi-modal display that includes images, graphics, text, and sound.
Q: Where do I get the application?
A: You can get the application from your local National Weather Service Forecast Office. You have to register first and then download and install the application. There will also be installation instructions there as well.
A: You must be running a Java-enabled Web browser (Netscape 4.08 or later or Internet Explorer 5.0 or later). The system connects to the WFO's Web Server, and can be started in 2 ways:
Q: The system complains that it cannot find java.
Fix: Make Sure that your PATH variable includes the directory of the Java Development Kit or the Java Runtime Environment that you installed with this application.
Q: The system complains that it cannot find display.Display.
Fix: Make Sure that you have set the CLASSPATH variable to include that directory d:\ldadjavaA
Q: The system will not load new data.
Fix: Exit the system and restart your browser. Clear all the caches in your browser and then restart the program.
Netscape Users:
Go to Edit, select Preferences, and choose Advanced. Then click the Clear Memory Cache and Clear Disk Cache buttons.
Internet Explorer Users:
Go to Tools, select Internet Options, and choose the General tab. Then click the Delete Files... button in the Temporary
Internet Files section.
Q: Who supplies the maps backgrounds and what is the format?
A: The map backgrounds are in an ArcInfo shapefile® format. When you connect to our Web Server using a browser, the required maps are downloaded to your system from the WFO web server. However, if you are connecting via the application, you can set the application to view the WFO's maps, your maps, or a combination of both. All maps at the WFO are compressed and clipped to this locale. If you would like to do the same for your maps, please use the MapClipper program supplied with the system.
Q: What is the source of radar data?
A: The WFO database contains NEXRAD data from one or more local radars.
Q: What is the radar update rate?
A: Every 5 to 6 minutes in precipitation mode, otherwise every 10 to 15 minutes.
Q: How often are observations updated?
A: Observations are updated every 15 minutes, although the display shows an hourly time notation Observations from the various networks can be at different intervals; we bin them in 1 hour files but update your system with the latest information every 15 minutes.
Q: How often are images updated?
A: The Local scale images (LAPS) are updated every hour at roughly 23 minutes past the hour. The National scale analysis (MSAS) are update every hour at roughly 20 minutes past the hour. The Local forecast products (IFPS) are updated whenever your friendly neighborhood forecaster generates an updated gridded forecast. This could be multiple times per hour. All images are valid for the time that is listed on the legend.
Q: So what are LAPS, MSAS, and IFPS?
A:
Q: How often is quality control updated?
A: Quality Control is a 2 step process. The first step, a coarse test of validity is performed every 5 minutes and a more extensive test is performed every hour. The latest of these test is available to you every 15 minutes.
A: Mozilla is an organization that maintains and releases new versions of Netscape and Communicator code. See the Systems Requirements page for more details.
Q: Will we ever see lightning strikes?
A: Lightning data are owned and sold through a private company. This system is extensible; it will load lightning data if you write the Java module and acquire the data. Please contact us if you are interested in doing this and we can provide you with the API for the application.
Q: How fast does my modem need to be?
A: We recommend 28.8 kbps or faster.
Q: I displayed my radar with local temperature; why doesn't all the radar animation show?
A: Whatever animatable product you displayed last will be used to provide the time steps for the animation sequence. Make sure that the one you want to control the animation is the last product you choose onto your display.
Q: What is an animatable product?
A: An animatable product is any image, contour/overlay weather, or radar product. Geographical datasets and Observations are not animatable, so choosing these products at any time will not cause any problems with animation.
Q: What is Probe and how can I use it?
A: Probe is the capability to sample and display weather parameters for any selected geographical object. The object can be a county, city, river basin, etc. In essence, a geographical object is any polygon, line, or point in a Shapefile. (Note: In this version, line analysis is not yet implemented.)
Q: How can I add in my own Shapefiles?
A: First of all, you have to be running as an application (see Question 2, above). Using the EMDS Configurator, you can generate your Geographical menus and tie in your Shape files. Remember to first clip and compress your files and store them in the localConfig directory in your EMDS install directory.
Q: How can I add in my own GIF files?
A: You must be running as an application; see Question 2, above. Use the EMDS Configurator to generate your Image menus under the Geographical menu and tie in your Image files. Remember to store them in the localConfig directory in your EMDS install directory.
Q: I added my GIF files but they are upside down. What happened?
A: The problem is the settings that you used for the lat/lon pairs when you used the EMDS Configurator. You must supply a string containing the image's four corners in the correct order, separated by ampersands:
ULLon&ULLat&URLon&URLat&LRLon&LRLat&LLLon&LLLatWhere UL refers to upper-left, UR upper-right, LL lower-left, and LR lower-right. These corners are used to scale and translate the image to the correct position and area of the screen.
Q: My WFO has provided me with a Local Dialin account. How do I connect to LDAD?
A: First get the following information from the WFO LDAD Administrator: