JPSS1 VIIRS RSB Sensor calibration using monochromator-based and laser-based methods

Transcription

1 JPSS1 VIIRS RSB Sensor calibration using monochromator-based and laser-based methods Jinan Zeng 1, Tom Schwarting 2, Jeff McIntire 2, Jack Ji 2, Hassan Oudrari 2, Jack Xiong 3, and Jim Butler 3 1 Fibertek Incorporation, Dulles Technology Dr., Herndon, VA Science Systems and Applications Incorporation, Lanham, MD Goddard Space Flight Center, NASA, Greenbelt, MD CALCON Logan, UT Aug , 2016

2 Outline 1. Introduction 2. Monochromator-based (SpMA) and laser-based (T-SIRCUS) calibration methods Different approaches to obtain absolute spectral responsivity (ASR) and relative spectral responsivity (RSR) for RSB from M1 to M7 3. Characterization results of J1 VIIRS RSB sensors using two methods I. Detector-to-detector RSR variation at each band II. Spatial dependence of bandwidth, centroid/central wavelength III. Analysis of cross talk influence on band shape using complementary results from two calibration methods 4. Verification of RC2 test results 5. Conclusions

3 General introduction SpMA T-SIRCUS Avg RSR lookup table generation Operation processing using band average: F factor, band-averaged BRDF, Equivalent Black Body Temperature (EBBT), band-averaged detectable radiance, background radiance etc.

4 Comparison of IB RSR between J1 and SNPP Blue SNPP Red JPSS1 1. Large difference of M1-M7 between J1 and SNPP 2. T-SIRCUS spectral range

5 Importance of detector to detector RSR Next scan Track direction Scan direction

6 Detector to detector RSR variations 1. Significant change of spectral radiance IB 2. Operational processing uses band averaging

7 SpMA & T-SIRCUS

8 SpMA Overview Spectral Measurement Assembly: Dual monochromator system using tungsten bulb and ceramic glow bar sources (all the bands from 400 nm to nm) Resolution vs radiance output Reference standard Double Monochromator FPA Slit illumination

9 Traveling SIRCUS Spectral Irradiance and Radiance Calibration Uniform Source + Reference Standard Tunable lasers for VISNIR bands Pulse duration: 5-10 ps Rep rate: MHz OPO Signal nm OPO Signal SHG nm Ti : Sapphire laser nm Linewidth: < 0.01 nm Quasi-CW operation DCM Dye Laser nm R6G Dye Laser nm CW operation Fiber optics Monitor radiometer Flood illumination with single wavelength Integrating sphere VIIRS

10 Absolute spectral response (ASR) and relative spectral response (RSR) using two calibration methods 1. SpMA (spectral resolution: 2 nm, all the bands) Obtain RSR with relative spectral output (RSO) of trap Si detector, and Pyroelectric detector, but additional absolute radiance measurements (RC2) needed to determine ASR RSR(λ) = dn(λ )/RSO(λ) ===>> ASR(λ) Slit illumination rule out cross-talks from other bands 2. T-SIRCUS (spectral resolution: < 0.01 nm, VISNIR of RSB) Obtain ASR with a uniform source by comparing with a transfer radiance meter, and normalize ASR to get RSR ASR(λ) = dn(λ )/L(λ) ===>> RSR(λ) = ASR(λ)/ASR max Flood illumination close to practical operation with cross-talks from other bands T-SIRCUS SpMA Slit image ASR: dn/(w m -2 Sr -1 ) VIIRS VisNIR focal plane

11 J1 VIIRS RSB Sensor Characterization

12 J1 VIIRS Spectral Performance Specification 100% 50% λ lower OOB λ upper OOB Out-of-band (OOB) 1 % Bandpass Extended bandpass (IB) 1 % Out-of-band (OOB)

13 Comparison of RSR and Bandpass Filter Performance ASR = T HAM x T dichoic x T filter x Response

14 Comparison of RSR and Bandpass Filter Performance

15 Detector to Detector RSR Variation

16 Detector to Detector RSR Variation

17 Average RSR of T-SIRCUS & SpMA

18 Average RSR of T-SIRCUS & SpMA

19 Average RSR of T-SIRCUS & SpMA

20 Comparison of J1 VIIRS RSB Sensor performance Track direction Track direction

21 Comparison of J1 VIIRS RSB Sensor performance Track direction Track direction

22 Comparison of J1 VIIRS RSB Sensor performance Track direction Track direction

23 Comparison of RSR OOB of T-SIRCUS & SpMA OOB, % J1 Spec J1 Measure S-NPP Measure J1 SpMA J1 SIRCUS M1 1 % 0.35 % 2.19 % 0.15 % 0.33 % M2 1 % 0.52 % 0.93 % 0.28 % 0.51 % M3 0.7 % 0.43 % 1.15 % 0.19 % 0.38 % M4 0.7 % 0.37 % 3.65 % 0.2 % 0.31 % M5 0.7 % 0.37 % 2.70 % 0.23 % 0.36 % M6 0.8 % 0.4 % 1.64 % 0.19 % 0.33 % M7 0.7 % 0.16 % 0.62 % 0.07 % 0.1 % SpMA: Slit illumination T-SIRCUS: Flood illumination

24 OOB feature verification using SpMA and T-SIRCUS Leakage? SpMA Merged T-SIRCUS and SpMA RSR (V2) M1 M3 M6 M7

25 M4 RSR with cross-talks from other bands by T-SIRCUS M4 M2 M1 M3 M5 M6 M7

26 M1 RSR with OOB features from SpMA Leakage V1 (SpMA) Cross-talk from M1 to M4

27 M2 RSR with OOB features from SpMA Leakage Cross-talk from M2 to M4

28 M3 RSR with OOB features from SpMA OOB M3 Cross-talk from M3 to M4

29 RSR OOB for M5, M6, and M7 from SpMA

30 Application of J1 VIIRS RSB RSR

31 Verification of calibration coefficients from RC2 test RC-2, Reflective Band Radiometric Response and Sensitivity Multiple lamp sources Flood illumination using broadband light source SIS100 VIIRS Attenuator (0.57) M6 linear response L=C 0 +C 1 xdn 1 +C 2 xdn 1 2 TxL=C 0 +C 1 xdn 2 +C 2 xdn 2 2 T=(C 0 +C 1 xdn 2 +C 2 xdn 22 )/(C 0 +C 1 xdn 1 +C 2 xdn 12 ) =(h 0 +DN 2 +h 2 xdn 22 )/(h 0 +DN 1 +h 2 xdn 12 ) where h 0 =C 0 /C 1, h 2 =C 2 /C 1 Best fit without validation

32 Spectral Profile of Input Radiance Spectral radiance W/m2/Sr/um

33 Spectral Profile of Input Radiance DN= L(λ) x ASR(λ) x d λ L = C 1 x DN or (C 0 +C 1 xdn+c 2 xdn 2 )

34 Result of DN and radiance for flat spectral radiance input using the linear coefficient, C 1 x10-3 DN= L(λ) x ASR(λ) x d λ x10-3 L = C 1 x DN

35 Comparison of gain coefficient C1 and DN for flat spectral radiance input

36 Result of DN and radiance for solar radiance Input using the linear coefficient, C 1 x10-3 DN= L(λ) x ASR(λ) x d λ x10-3 L = C 1 x DN

37 Result of DN and radiance for flat spectral radiance input using all the coefficients x10-3 DN= L(λ) x ASR(λ) x d λ x10-3 L =C 0 +C 1 xdn+c 2 xdn 2

38 Result of DN and radiance for solar radiance Input using all the coefficients x10-3 DN= L(λ) x ASR(λ) x d λ x10-3 L =C 0 +C 1 xdn+c 2 xdn 2

39 Conclusions 1. Verification of spectral shape of RSR 2. Detector to detector RSR variation investigated (< ± 10 %) 3. Comparison of Avg RSR results from SpMA and T-SIRCUS (< ± 5 %) 4. Cross-talk study using RSR OOB from SpMA and T-SIRCUS 5. Validation of RC2 results using ASR (< ± 1 %) Future work: o Validation of RC2 results with accurate lamp radiance spectra using ASR of T-SIRCUS o Scene dependant calibration

40 Acknowledgements Chris Moeller CIMSS, Univ. Wisconsin, 1225 West Dayton Street, Madison, WI Joel McCorkel Goddard Space Flight Center, NASA, Greenbelt, MD David Moyer The Aerospace Corporation, El Segundo, CA 90245