STAR Calibration Support for GOES Post Launch Test (PLT) X. Wu & F. Yu NOAA/NESDIS/STAR/SPB & NOAA

PLT Overview GOES PLT is similar to POES OV in many ways –Longer, more complicated spacecraft maneuver Engineering Test –Functionality of component and system (instrument) Science Test –Products generation from instrument measurements Radiance quality can be part of either, but has been primarily part of the Science Test.

PLT History (Science Test) GOES-8 (1994): –1 st of its kind – learn to make the best use of the data –Radiance is validated (quite substantially), but little beyond GOES-9 (1995): –Still not formal, if any. GOES-10 (1997): –Solar panel deployment led to yaw flip –Science Test in April 1998 to make sure it’s compatible with GOES-8/9 1 st 1-min rapid scan. Goes-11/12 (2000/2001): –Formal and routine GOES-13 (2006) –Significant change in hardware; more sophisticated Science Test

PLT Structure Engineering test has always been led by NASA Science Test was earlier led by CIMSS and later co-led with OPDB or CIRA. Calibration support –STAR personnel detailed at SOCC With contractor support at SOCC –Engineering Test Oversee the Implementation of “CPIDS” (examples). Supply certain tests (example) –Science Test Diagnose and correct for operational and calibration anomalies (examples)

Calibration Database Before/During PLT Specify and verify –Coefficients and limits –Changes (e.g., BB dwell) –Generate some, e.g., band correction, scan mirror emissivity OGE Compatibility Test –Unlike POES, GVAR is not Level 1b (in its traditional definition) –Need to test calibration and geo-location

Test Description for PLT TEST NUMBER:IC115 TEST NAME:Benefits of Imager Extended Blackbody Dwell TEST ENGINEER:Angel Butts TEST TYPE:Characterization TEST DURATION:N/A SPECIFICATION REFERENCES: GOES-NOPQ CCR 4233 Rev. (8/22/00): Increase SN08 Imager Black Body Dwell Time. GOES-NOPQ CCR 4233 Rev. B (2/27/01): Imager Blackbody Dwell Modifications and Miscellaneous Cleanup of the GOES NOPQ Imager and Sounder ICDs. OBJECTIVES: To quantify the reduction in the variability in the means of the blackbody counts, the calibration slopes, and the frame-mean striping resulting from the increase in blackbody dwell time from 0.2s to 2.0s. DESCRIPTION 1.Data collected during 24 hours of successive blackbody events will be processed in parallel in two MSPS’s. At each blackbody event, each MSPS routinely computes the means and standard deviations (in units of 10-bit digital counts) of the sequence of blackbody samples in each IR channel. In these computations, at each event one MSPS will use only the first 1000 blackbody samples, while the second MSPS will use the entire nominally 10,000 samples. We will use the means and standard deviations of the blackbody count levels, routinely produced by the MSPSs, to compute the standard errors of the means for each channel for each blackbody event. The standard errors from the two MSPSs will be compared. (If the distribution of blackbody data were close to normal, their ratio would be approximately  10.) Also, the standard deviations (in counts) will be converted, through the calibration, to units of temperature and compared with the noises computed from thermal/vacuum tests and the noises computed in PLT # IS004--Imager IR Channel Noise Equivalent Temperature Differences. The S.D.s from the 1000 and the 10,000 samples should be nearly the same, both of them should be about the same as the S.D.s from the other tests, and all of them should meet spec.

Calibration Support During/After PLT Operational anomalies – confirm and diagnose –GOES-13 Sounder visible channel boost –GOES-14: cal/nav coeff., buffer overflow, Imager Ch6 det ID Calibration Anomalies – things were more or less complicated –Scan mirror emissivity –Midnight Blackbody Calibration Correction –Imager visible channel normalization –Radiance validation – accuracy & precision; GEO-GEO & GEO- LEO; vis & IR, imgr & sndr –Co-registration –Stray light –Sounder striping

Preliminary

Issues Need data during PLT –Both in real time and archived –Better for GOES-14, but far from ideal Even available, GVAR is not Level 1b –Often a limiting factor for detailed investigations Need more dedication