Java-IRAS Notes (as of 10-22-04) --------------- Java-IRAS is a Java based application for displaying WSR-88D level II data from files. Although currently under development, enough functionality exists for general analysis purposes. This release of the software is "as-is" and no warantee is provided. This document describes what is needed to run Java-IRAS and some basic information on how to use it. Installation ------------ Java-IRAS has been developed using Java release 1.3 from Sun Microsystems. One can get the latest Java run-time software from Sun's web site. The Java-IRAS software is distributed in Java archive format. The ".jar" file can be installed using the "jar" command as follows: % jar xvf where is the name of the Java archive file. One should install the software in a directory pointed to by the CLASSPATH environment variable. Starting Java-IRAS ------------------ To run Java-IRAS enter the following: % java Iras After a few seconds, a window should appear with a number of selections and a blank display region. Various application output is written to standard output. This provides some feedback as to what is going on and also is used for debugging purposes. One can generally ignore this information but useful information is displayed in any event. USING JAVA-IRAS --------------- Most Java-IRAS functions are controlled from the menu bar at the top of the window. Only a handfull of items are displayed to the right of the data display region. These selections control the elevation cut (PPI view) or level (CAPPI view). File Menu Item -------------- Since the purpose of Java-IRAS is to display WSR-88D level II data one should open a file using the Open" selection in the File menu. A standard File Dialog is used for selecting the level II file. Once a valid level II file is selected, the entire file is read and a set of internal lookup tables are created for quick access to various radial data. Once this process is completed, a set of elevation buttons are created and displayed to the left of the display region. A button is created for each nominal elevation in the file. NOTE: No validation is performed on the data file to ensure that it is in level II format. It is the users responsibility to select a valid data file. To close the Java-IRAS application select the "Exit" button from the File menu. Color Menu Item --------------- The Color menu will eventually contain selections to control the color tables used to display the radar data. Currently it only contains a single toggle ttem, "Use Default Color Tables". This item controls whether the standard WSR-88D color tables/data ranges are used to display radar data. By default it is set. If unset, then the user can change the data/color assignments by changing the data ranges for each moment. The data ranges can be changed in the Control Properties dialog (activated from the Control menu). Control Menu Item ----------------- The Control menu contains selection which affect how radar data are displayed in the data display region. The Display Magnification radio buttons control the zoom factor used when displaying data. By default no magnification is used (1:1). Data are displayed out to 460 km in all directions. When using the higher zoom factors you would typically want to recenter the window over the item of interest first. The Display Units selections control the units used when displaying range and velocity values. By default kilometers is selected. The Loop selection causes all of the images in the image buffer to be displayed one after the other. The rate that they are displayed can be controlled with the loop interval selection in the Control Properties dialog. Before an image is displayed, it is created and stored in the image buffer. When a new image is created, a copy of the old image is retained in the image buffer. Up to 20 images are retained at a time. If the zoom factor, the cut (PPI) or level (CAPPI) is changed, then the image buffer is cleared. The intent of the image buffer is to allow one to animate images of the same properties over multiple volumes. The Auto Update selection controls whether the data display is updated when a new file is detected in the data directory. Typically, one would first display a data file before selecting this item. This will define the directory to scan for new files in. By default, the display is updated only when the currently active cut in the new file is available. However, to update the display whenever a new cut is available in the new file, select the Update Volme selection in the Control Properties dialog. The Properties selection activates the Control Properties dialog. From this dialog one can define the radar coordinate, loop rate, and auto update mode. Analysis Menu Item ------------------ The Analysis menu contains various data analysis function. Currently, it contains a single selection, RHI. The RHI item activates the RHI display window. The a reconstructed RHI is displayed along the closest radial to the last selected point in the PPI or CAPPI display region. The window is updated whenever a new point is selected. Moments Menu Item ----------------- The Moments menu contains selections to control the moment being displayed in the data display region and the range of values that are displayed. The choices are: Reflectivity (default), Velocity, and Spectrum Width. The Properties selection displays the Moments Properties dialog from which the min and max data ranges for each moment can be set. Overlay Menu Item ----------------- The Overlay menu contains selections to control what types of non-radar data are displayed over the radar data in the data display region. Currently two types of overlay data are supported: Grid and Maps. The Grid item controls whether a polar grid is displayed after new radar data are displayed in the data display region. By default, the Grid item is set. The Map item controls whether maps are displayed over the radar data. The map file and properties must be defined in the Map Properties dialog. Also, the radar coordinate must be first set in the Control Properties dialog. Otherwise, no map will be displayed (or displayed improperly). The Properties selection acivates the Overlay Properties dialog. From this dialog you can define the polar grid and map properties. Display a PPI ------------- To display a PPI for any one of the nominal elevation angles select the desired elevation button. These buttons are displayed ONLY after a valid level II data file has been opened. The buttons reflect the elevation cuts available in the VCP associated with the open file. Display a CAPPI --------------- To display a CAPPI for a selected height (AGL), set the height to the right of the display region (make sure to press the enter key after the height data as been entered) and set the CAPPI radio button. If the CAPPI radio button is already set, the new CAPPI is generated after the new height has been entered. Mouse Buttons ------------- The three mouse buttons have special meaning when pressed while the cursor is in the display region. The right mouse button is used to locate the cursor, with respect to the radar. This information is displayed at the bottom of the display region. If the RHI window is open, then a new RHI is constructed for the radial closest to the selected location. The center mouse button is used to relocate the display region center to the selected point. This is usefull when one wants to position a particular echo in the middle of the display region. This is very important when using higher zoom levels. The right mouse button resets the window center so that the radar is displayed at the display region center. Final Comments -------------- Work is continuing to add additional features to Java-IRAS. Updates will be made available whenever new features have been added. Comments on how to improve this software are welcome. Since this work is being done on my free time, the scope of what can be done will be limited by my schedule. I hope to continue supporting this effort indefinitely and hope that you find it usefull. If you have any questions or comments you can send them to me at: David.Priegnitz@nssl.noaa.gov Bug Fixes --------- 04/24/02 - Corrected a problem with the VCP label and cut buttons not getting updated in auto-update mode when the VCP changes. This condition was not handled in the original design. 10/14/02 - If an elevation cut was not available then the lowest cut was being displayed. Normally one wouldn't ever run into this situation as the level II file is normally complete. In this case, special processing was being done by the ORPG to dealias velocities and then write them back to the level II record. Under certain conditions, the elevation cut would not get processed by the ORPG so the resultant level II file (generated by a different utility) was missing the cut. 07/12/04 - The code has been updated to remove VCP dependencies. VCP information is no longer hard-coded so that if/when new VCPs are added to the WSR-88D Java-IRAS will be able to process them without any code changes. This problem came to light during a recent change where two new VCPs were added and the data could not be displayed using this tool. 07/13/04 - I found a bug in the CAPPI code which caused a problem with split cuts. Basically, CAPPIs in previous versions were not being generated correctly. This problem has been fixed in this version. 10/22/04 - A number of enhancements have been made to the software in this version. 1) Java-IRAS now supports Universal Format radar data files. The File menu has been updated to include selections for Universal Format and Level 2 file types. The Moments menu has been enhanced to dynamically build the moments list for all moments defined in the selected file. The elevation cut list is built with all elevation cuts defined for the active moment. NOTE: Every attempt was made to associate mnemonics to moment type. However, since specific mnemonic definitions are arbitrary, the color table that is associated with a given mnemonic may not be what the user desires. The current associations between mnemonic and type are as follows: reflectivity - CZ, DZ, Z1, S1 velocity - VF, VE, VR, VT, VP, V1 spectrum width - SW, W1 Any moment not in this list will be displayed using the velocity color scale. 2) For NEXRAD Level 2 data, Java-IRAS previously assumed that reflectivity bins were spaced 1 km apart and Doppler bins 0.25 km apart. Java-IRAS now determines the spacing from the "Surveillance Range Sample Interval" and "Doppler Range Sample Interval" elements in the radial header. The main result in this change is that echoes will be closer to the radar than previously displayed (data indicates bin spacing slightly less than 1 km for reflectivity and slightly less than 0.25 km for velocity and spectrum width). 3) Direct bin interrogation has been added in this version. If you press the left mouse button inside the PPI/CAPPI window the moment value is also displayed along with the location. NOTE: This only works properly for PPI displays. 4) A problem was fixed in the CAPPI display code which erroneously displayed data from the highest cut in regions closest to the radar. This version cuts off data where the highest elevation plus one half beam with crosses the specified height. 5) The RHI function has been updated. In previous versions, when the RHI window was closed it could not be reopened. This has been fixed. Also, the RHI window updates automatically when a new moment is selected so one no longer has to try to reselect the RHI radial.