BAMEX Radar WSR-88D Supplemental Data (level 2) [MMM]

This datasets contains WSR-88D radar data collected during BAMEX.

To improve the archival of WSR-88D level II data during BAMEX, several WSR-88D sites outside the CRAFT network saved the data directly on local workstation hard drives in addition to Exabyte tapes.

The seven sites were:
KARX La Crosse, WI
KDMX Des Moines, IA
KEAX Kansas City, MO
KFSD Sioux Falls, SD
KMPX Minneapolis, MN
KOAX Omaha, NE
KSGF Springfield, MO.

The workstations were collected by the Mesoscale and Microscale Meteorology Division in Boulder, CO, in July 2003, and data were downloaded to the division data server, bay. After decoding and tarring the individual radar volumes into daily files, they were and recompressed with gzip, and copied to NCAR Mass Storage under the user directory /AHIJEVYC/BAMEX-Archive2. Data have now been moved to their final archive location /JOSS/DATA/RAW/BY_PROJECT/BAMEX/RADAR/WSR-88D in directories by radar site.

An example of a daily tar file is

/JOSS/DATA/RAW/BY_PROJECT/BAMEX/RADAR/WSR-88D/KARX/KARX_2003.0704.tar.gz

where KARX is the 4-letter identifier for the originating WSR-88D site (La Crosse, WI), 2003 is the year, and 0704 is the 4-digit date (July 4th).

Each tar file was compressed with gzip (gzip -d to decompress) and holds all radar volumes for a single date.

The individual radar volumes within the tar files were named

KARX_2003.0704.013845.Archive2

where, once again, KARX is the radar ID, 2003 is the year, 0704 is the date, and 013845 is the UTC time in hhmmss format.

Verbose lists of the tar files' contents for each radar are in KARX_tar_inventory.txt, KDMX_tar_inventory.txt, etc.

COMPRESSION SCHEMES

The workstations ran Unidata's Local Data Manager (LDM) version 5.2 to intercept and archive the radar volumes. The directory structure and file naming convention on the workstations followed this pattern: /home/ldm/data/nexradII/KARX/20030704013845.ldm. This particular file came from KARX (La Crosse, WI) on 4 July, 2003, at 01:38:45 UTC.

When the workstations arrived at MMM, the radar volume data files were still encoded in nexradII format, a compression scheme that required the nexradII decoder. For long-term storage, the compression scheme was changed from nexradII to gzip, a standard on most operating systems. The original nexradII encoded files were tarred into daily files and temporarily stored, but are not archived permanently. As of 2003.0910, the CRAFT FAQ web page stated that the nexradII decoder was available in the CAPS LDM 5.2.1 RPM and under the nexradII link at http://www.caps.ou.edu/rtstats/craftfaq2.html. The decoder was based on the bzip2 compression/decompression and uses the bzip2 libraries. One could not use the bzip2 program by itself to decompress the data without first modifying the data. It was the uncompression piece of the CRAFT project and was supported by CAPS, not Unidata.

There are verbose inventories of the tarfile contents for each radar.

README AUTHOR

David Ahijevych (ahijevyc@ucar.edu)