CAMEX-4 Mobile X-band Polarimetric Weather Radar Table of Contents
Introduction The Convection And Moisture EXperiment (CAMEX) is a series of field research investigations sponsored by the Earth Science Enterprise of the National Aeronautics and Space Administration (NASA). The fourth field campaign in the CAMEX series (CAMEX-4) ran from 16 August to 25 September, 2001 and was based out of Jacksonville Naval Air Station, Florida. CAMEX-4 focused on the study of tropical cyclone (hurricane) development, tracking, intensification, and landfalling impacts using NASA-funded aircraft and surface remote sensing instrumentation. Mobile X-band Polarimetric Weather Radar on Wheels (X-POW) is an X-band Doppler scanning radar operating at 9.3 GHz. with horizontal and vertical polarization. Used for detection and detailing surface rainfall rate and precipitation classification fields, 3D precipitation microphysical retrievals including water/frozen hydrometeor contents and drop size distribution profiles, X-POW was located in the Florida Keys during the CAMEX-4 field experiment. The table below shows the X-POW radar specifications:
This information is for running on UNIX/LINUX machines. Windows documentation is not provided. Supplied with the documentation is a file named xpow.tar. This tar file contains a data extraction program, instructions and a sample dataset. The program should be used on data from other days to allow the user to manipulate it into a more useable form. Once this file is 'untarred', there will be created a directory named XPOW_READ. In this directory are the following directory and files:
The XPOW_README.TXT is shown below: This is the README.TXT file for XPOW Version 1.02 ************************************************************************* This file contains information on how to run the C program XPOW, that reads the XPOW data. ************************************************************************* ftp://ghrc.nsstc.nasa.gov/pub/doc/camex4/c4gxpow/XPOW_README.TXT This program has been tested on HP and SGI UNIX and LINUX platforms. You do not need any setup or installation to run it. The main programs are called XPOW_PPI.C (for reading sector scans), XPOW_PPI2.C (for reading full 360 deg PPI scans), and XPOW_RHI.C (for reading RHI scans). These are the programs you need to modify to adjust to the specifics of your application.Before run the program it is important to create five list files that contain the data you would like to read. The data we read are: Horizontal polarization reflectivity (listfile with extention .zh), vertical polarization reflectivity (extention .zv), differential phase shift (expention phd), spectral width (extention sw), and radial velocity (extention vel). Be aware the path of the data (it is hardcoded in the programs).Enjoy! ----------------------------------------------------------------------- In the second paragraph above, the instructions require the user to create listfiles. These are already created for use with this example program, and is included with the documentation and software. When using 'real' instead of the data that comes with XPOW.TAR, you need to do that yourself. Here is code that will do that. NOTE: THE CODE BELOW IS NOT SUPPLIED IN THE FILE NAMED XPOW.TAR.: ***************************************************** # script "xpowlist" ls -1 ppi2*.ncp >> list_ppi2_ncp ls -1 ppi_*.ncp >> list_ppi_ncp ls -1 rhi*.ncp >> list_rhi_ncp *************************************************** To prepare the data files for processing, run the above script, and then follow the instructions in paragraph one in the README.TXT file shown above. If you are running the example file, you'll be able to compare your output to the output file supplied separately with this documentation. (That file is called example_output.dat). Create an output file ('make', then 'freq >output'). Here are the first ten lines of output from the example_output.datfile.
These software and documentation files can be downloaded here: Data Format XPOW data are 'tarred' into daily data files of the form:
where c4xpow represents CAMEX4 and the xpow instrument, yyyy.ddd is the four digit year and day of year. When untarred, these data should be put into the /XPOW_READ/Data directory. Once there, run the xpowlist script shown above to create the listfiles. Note, these listfiles have to be in the /Data directory. At this point, run 'make' and 'freq > [output filename]' and the data is ready for use in radar presentation programs. Note: It is assumed that the user is familiar with radar presentation programs, and as such, they are not provided here. Contact InformationThe data producer is:
or, as an alternative:
To order these data or for further information, please contact:
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