Blackbody Calibration

DOC NOAA NESDIS


Blackbody Calibration



	Correction for GOES Imager Midnight Blackbody Calibration Error
	Description of Problem
	Calibration Correction
	Correction Algorithm
	Slide 5
	Scence Temperature Errors Predicted from Slope Errors vs Time
	Observed Scene Temperature Errors vs Time
	Observed vs Predicted Errors
	Slopes vs Time
	Uncorrected Slopes vs Time
	Corrected Slopes vs Times
	Parallel Test of Midnight Blackkbody Correction (MBCC)
	Slide 13
	Slide 14
	Conclusion

Parallel Test of Midnight Blackbody Correction (MBCC)

Parallel (to operations) test of MBCC occurred Jan. 13-16, 2003, with data from GOES-10 Imager.
Parallel (MBCC) GOES-10 GVAR stream was distributed via the GOES-9 transponder.
Opn’l & parallel data were collected and compared at SSEC Data Center (U. Wisconsin)
The following two figures show their results for Jan. 14 & 15
- The MBCC was effective from 0600 to 1000 UTC in Imager channels 2 (SW—3.8 :m), 3 (WV—6.7 :m), and 4 (LW—10.7 :m). (Local midnight for GOES-10 is at 0900 UTC.) At those times, the MBCC increased the scene temperatures, as expected.
- An unexpected “correction,” having opposite sign, was also made between 1000 and 1300 UTC in channels 3 and 4. This “correction” is not valid and occurred because of an algorithm error. The error has since been corrected. In the future, this invalid “correction” will not be made. (This catch illustrates the benefits of parallel testing. We are greatly indebted to our colleagues at U. Wisconsin.)

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