Precipitation Radar

PR Calibration
The PR instrument requires little day to day commanding. External calibrations will be performed approximately every two months, and internal calibration once a week, respectively. Nominally, the external calibration will be performed in the limited scan mode, which will use 7 of the 103 beams and disregard the remaining. The calibration must be performed when TRMM passes over an ARC located in Japan. The NASDA/EOC will define the time and the center beam number at which this calibration must be performed. An internal calibration will be performed in the area where RF radiation of PR is prohibited.

External calibration - calibration using active radar calibrator (ARC) on ground
- check overall PR performance

CRL Kansai Advanced Research Center Performing experiment
Calibration of PR transmitters・・・it compares ARC received power computed from PR transmit power with real observed values (blue line).
Calibration of PR receivers・・・it compares PR received power with computed value from ARC transmit power (Red line).

they agree within dB

Internal calibration - internal calibration loop of PR
- calibration of receivers (compute the relation between received power and output count values)
A calibration table is made by using 32 steps of the attenuator
−performed everyday
−used for algorithm 1B21 (count value is converted into dBm.)
 
  1. Algorithms ・・ PR Algorithm Flow / Example of PR Output Product
  2. Standard Products ・・ Samples
  3. PR Calibration and Validation ・・ Calibration / Validation Result