1. 24/10/2006Dr. J.J. Remedios, GIST 2006 1 GERB Spectral Calibration Nick Nelms 1*, Oliver Blake 1, Jacqui Russell 2, John Remedios 1, 1 SRC, Physics and Astronomy, University of Leicester, U.K. 2 Imperial College, U.K. * Now at ESTEC, Netherlands, U.K. http://www.leos.le.ac.uk/

2. 24/10/2006Dr. J.J. Remedios, GIST 2006 2 Leicester Spectral Calibration Facility

3. 24/10/2006Dr. J.J. Remedios, GIST 2006 3 LSCF Operations 1.Reference detectors (Si detector and pyranometer) calibrated at NPL. 2.Use 9 GERB pixels to map entire beam shape as reference detector is much larger than a GERB pixel. 3.N.B. Beam shape is a function of wavelength. 4.Move 8 GERB pixels at a time into a given position in the beam (32 measurements to cover array). 5.Data recorded in LSCF, analysed at Imperial College 6.Difficulties: Source variability in the shortwave. Low signals in the longwave and hence takes a long time to do measurements. 7.Reference detector calibrations ideally need to be re-done. 8.GERB4 FM calibrations nearly completed (this week). Flight spare next.

4. 24/10/2006Dr. J.J. Remedios, GIST 2006 4 Results I Data recorded by Oliver Blake, LU Plots by Jacqui Rusell, Imperial College

5. 24/10/2006Dr. J.J. Remedios, GIST 2006 5 Results II Data recorded by Oliver Blake, LU Plots by Jacqui Rusell, Imperial College

6. 24/10/2006Dr. J.J. Remedios, GIST 2006 6 Results III Data recorded by Oliver Blake, LU Plots by Jacqui Rusell, Imperial College

7. 24/10/2006Dr. J.J. Remedios, GIST 2006 7 Schedule (October 19 th )

8. 24/10/2006Dr. J.J. Remedios, GIST 2006 8 Conclusions and Future outlook Current calibration methodology successful in terms of mapping out pixel response of GERB linear array. Shortwave measurements limited to 0.33 microns because of source strength decrease towards 0.3 microns Infra-red signal-to-noise challenging. More limited pixel variability information may be the result. Will extend measurements to 20 microns. Future outlook 1.Linearity tests. The delivery of GERB 4 FM FPA. 2.Window transmission responses. 3.Reference detector overlap measurements. 4.Humidity tests 5.Two more GERB focal plane calibrations.