This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
GEMPAK installation at CCNY: 1) The GEMPAK home directory was moved from /scratch/gempak to /home/gempak in order to clean up the data directory and allow backup of the distribution without having to backup data. 2) NetCDF was installed under /usr/local/netcdf so that decoders for NetCDF data files (profiler, acars, etc) could be built. 3) The GEMPAK distribution was updated to Gempak 5.4 Patch level 15 to include the Y2K patches issued since the November period when CCNY originally downloaded the distribution. 4) The /home/gempak/Gemenviron was updated to reflect the new NAWIPS base directory location. 5) Gempak "dc" decoders were copied from $GEMEXE into the ~ldm/decoders directory. 6) Gempak decoder actions and NWX file entries have been created in the ~ldm/etc/pqact.conf file for realtime data decoding and filing. 7) For users to run GEMPAK, they should "source /home/gempak/Gemenviron" into their csh environment. This will add the $GEMEXE directory to the executable search PATH. To launch Garp, the user should type the command "ntl" to bring up the gui application widget, and then click on the Garp icon. Launching ntl provides a shared color access for the Gempak programs. Ntl should be launched prior to other color intensive applications such as web browsers. If the ntl program reports that not enough colors are available, then fewer colors can be requested, such as 64 satellite colors instead of the default 128, by launching ntl using command line options such as: "ntl -s 64". 8) The nsat_links script was installed in the ~ldm/decoders directory and the LDM user crontab was modified to run the script periodically. The nsat_links script copies satellite AREA files from the /scratch/mcidas directory into the GEMPAK $SAT tree. As requested by Ward Hindman, the nsat_links script will maintain a 24 hour archive of imagery in the $SAT tree for use with Gempak. 9) newlog entried were added to the LDM user crontab to rotate the GEMPAK decoder logs in ~ldm/data/gempak/logs. Steve Chiswell Unidata User Support