Using Zdrcal Results

The Zdrcal ZDR offset estimates are reported in result files *.zdrcal_results.

You can use these files to help maintain an accurate radar system level calibration of differential reflectivity ZDR.

To respond to an alarm about a significant deviation of the ZDR offset observed from the current radar setting, check the Zdrcal result file associated with the warning in the configured Zdrcal result directory.

To find the file, check the warning date and time in the result file name (typically, the file is the most recent one) If more recent result files have been generated, the recommended procedure is to inspect the later evolution of the offset estimate and judge the most likely current and future stable setting.
To view the most likely offset estimate:
1. In most cases, the most recent result file carries the most likely offset estimate. Retrieve the latest Zdrcal result by typing: zdrcal –update
  To specify an earlier result file, type:
  zdrcal –update:XXXyymmddHHMMSS.zdrcal_results
  Zdrcal looks for the most recent *.zdrcal_results file in the directory configured in Zdrcal (See Zdrcal Configuration File).
  When it has retrieved the result information, Zdrcal inspects the result quality, including:
  - Internal consistency of the estimate
  - Consistency of the radar site and data time span with respect to the current site and time
  - Whether the current ZDR offset setting is consistent with the setting used during the data sampling
  - Whether the result deviates from the configured alarm, significantly
2. When prompted, define how the utility should proceed (that is continue the update process, or terminate it).
  
  If you continue the update process, the utility updates the current radar settings in the signal processor, as well as updates the radar setup files to guarantee the continued use of the new setting after restart of IRIS/RDA processes.
You may also want to perform this task to verify the results of running Zdrcal.