NPP Visible Infrared Imaging Radiometer Suite (VIIRS) test program at the instrument and observatory level is complete and has provided an extensive amount of high quality data to enable the assessment of sensor performance

Butler, Jim

Chang, Vincent

Gleason, Jim

Lee, Shih Yan

Xiong, Jack

NASA Technical Reports Server

An Overview of NPP VIIRS Pre-launch and 
On-orbit Calibration and Characterization
Jim Butler, Jim Gleason, Jack Xiong
NASA, GSFC
and
Vincent Chang, Shih Yan Lee, Ning Lei, Jeff McIntire, Hassan Oudrari, 
Tom Schwarting, Junqiang Sun, and Aisheng Wu
NASA’s NPP Instrument Calibration Support Team/Element
CALCON 2011, August 29 – September 1, 2011 (Logan, Utah)
https://ntrs.nasa.gov/search.jsp?R=20110022516 2019-08-30T18:06:06+00:00Z
• VIIRS Instrument
• Pre-launch Calibration and Test Data Analysis
• Post-launch Activities
• Summary
Outline
NPP VIIRS pre-launch calibration and characterization effort included 
contributions from NASA calibration team, Aerospace, MIT/LL, UW, 
Raytheon, and NGC; VIIRS post-launch calibration and characterization 
will be performed by the SDR team managed by NOAA STAR with 
contributions from different groups.  
This presentation focuses on activities supported by the NASA’s team
Visible Infrared Imaging Radiometer Suite
Description
• Purpose: Global observations of land, ocean, & atmosphere parameters at 
high temporal resolution (~ daily)
• Predecessor Instruments: AVHRR, OLS, SeaWiFS, MODIS
• Approach: Multi-spectral scanning radiometer (22 bands between 0.4 µm 
and 12 µm), 12-bit quantization
• Swath Width: 3000 km
Status
• Successfully completed 
comprehensive TV performance 
testing at instrument and s/c 
levels
• Performance is nominal 
• NPP PSR completed (Aug 17-18)
• Ready for October 25, 2011 launch
VIIRS Bands and Products
VIIRS Band Spectral Range (um) Nadir HSR (m) MODIS Band(s) Range HSR
DNB 0.500 - 0.900
M1 0.402 - 0.422 750 8 0.405 - 0.420 1000
M2 0.436 - 0.454 750 9 0.438 - 0.448 1000
M3 0.478 - 0.498 750 3           10 0.459 - 0.479                0.483 - 0.493
500 
1000
M4 0.545 - 0.565 750 4 or 12 0.545 - 0.565           0.546 - 0.556
500 
1000
I1 0.600 - 0.680 375 1 0.620 - 0.670 250
M5 0.662 - 0.682 750 13  or 14 0.662 - 0.672              0.673 - 0.683
1000 
1000
M6 0.739 - 0.754 750 15 0.743 - 0.753 1000
I2 0.846 - 0.885 375 2 0.841 - 0.876 250
M7 0.846 - 0.885 750 16  or 2
0.862 - 0.877          
0.841 - 0.876
1000   
250
M8 1.230 - 1.250 750 5 SAME 500
M9 1.371 - 1.386 750 26 1.360 - 1.390 1000
I3 1.580 - 1.640 375 6 1.628 - 1.652 500
M10 1.580 - 1.640 750 6 1.628 - 1.652 500
M11 2.225 - 2.275 750 7 2.105 - 2.155 500
I4 3.550 - 3.930 375 20 3.660 - 3.840 1000
M12 3.660 - 3.840 750 20 SAME 1000
M13 3.973 - 4.128 750 21 or 22 3.929 - 3.989                  3.929 - 3.989
1000 
1000
M14 8.400 - 8.700 750 29 SAME 1000
M15 10.263 - 11.263 750 31 10.780 - 11.280 1000
I5 10.500 - 12.400 375 31 or 32 10.780 - 11.280   11.770 - 12.270
1000 
1000
M16 11.538 - 12.488 750 32 11.770 - 12.270 1000
 
Dual gain band
Name of Product Group Type 
Imagery * Imagery EDR 
Precipitable Water Atmosphere EDR 
Suspended Matter Atmosphere EDR 
Aerosol Optical Thickness Aerosol EDR 
Aerosol Particle Size Aerosol EDR 
Cloud Base Height Cloud EDR 
Cloud Cover/Layers Cloud EDR 
Cloud Effective Particle Size Cloud EDR 
Cloud Optical Thickness/Transmittance Cloud EDR 
Cloud Top Height Cloud EDR 
Cloud Top Pressure Cloud EDR 
Cloud Top Temperature Cloud EDR 
Active Fires  Land Application 
Albedo (Surface) Land EDR 
Land Surface Temperature Land EDR 
Soil Moisture Land EDR 
Surface Type Land EDR 
Vegetation Index Land EDR 
Sea Surface Temperature * Ocean EDR 
Ocean Color and Chlorophyll Ocean EDR 
Net Heat Flux Ocean EDR 
Sea Ice Characterization Snow and Ice EDR 
Ice Surface Temperature Snow and Ice EDR 
Snow Cover and Depth Snow and Ice EDR 
 
VIIRS 22 Bands:
16 M-Band, 5 I-Band and 1 DNB
VIIRS 24 EDRs
Land, Ocean, Cloud, Snow
* Product is a Key Performance Parameter (KPP)Similar MODIS bands
Pre-launch Calibration and Characterization
• NPP VIIRS (F1) testing program has completed all planned testing 
phases
– Ambient Testing: 06/20/07 – 11/30/07
– Sensor TVAC Testing: 05/03/09 – 08/23/09
– Spacecraft TVAC Testing: 03/10/11 – 04/25/11
• NPP VIIRS pre-launch testing has provided necessary test data to 
calibrate and characterize sensor performance, and to establish a 
baseline for sensor on-orbit operations
– Radiometric: gains, dynamic range, gain transition, linearity, SNR/NEdT, 
uniformity, uncertainty, polarization sensitivity, RVS, …
– Spectral: RSR or SRF (in-band and out-of-band), spectral band-to-band 
crosstalk, …
– Spatial: LSF/MTF, FOV, BBR, …
Pre-launch Calibration and Characterization
• NASA team has performed extensive test data analyses for VIIRS F1 
performance evaluation and requirement verification
– Participated key technical meetings, reviews, working group activities
– Supported on-site test data analysis during sensor and spacecraft TVAC 
calibration and characterization
– Produced 296 data analysis reports and 191 technical memos:
– EDU Test: 42 reports and 88 memos
– F1 Sensor-level Test: 217 reports and 96 memos
– F1 Spacecraft-level Test: 37 reports and 7 memos
• All performance waivers have been evaluated by NGST and reviewed 
by NASA team
– Most waivers have small to negligible EDR performance impacts
– Algorithm revisions and/or changes to Cal/Val tasks were added to support 
waivers
VIIRS F1 Performance Summary
• Radiometric
– VIIRS meets all Requirements for Signal to Noise Ratio, Dynamic Range, Gain 
Transitions, Linearity, Uncertainty, Stability and Polarization
– Minor Variances for: M1, I2 and M8 not reaching specified maximum radiance, but no 
impact is expected from these non-compliances; detector uniformity with potential for 
striping (plan for post-launch fix, if needed)
• Spectral
– Spectral Band Center, Spectral Bandwidth, Extended Bandwidth: Minor non-compliances 
are well characterized, no impact is expected.
– Integrated Out-of-Band and Optical Crosstalk between VisNIR bands is extensively 
analyzed, and a mitigation plan is in place. On-orbit cal/val activities will assess efficiency 
of this mitigation plan.
• Spatial
− IFOV, DFOV, HSR and BBR: Overall, performance meets Spec, with some detectors 
marginally out-of-Spec, but no impact is expected.
− Band-to-Band Registration: Meet requirements, except for few detector pairs. On-orbit 
jitter might degrade BBR performance, but impact on product quality should be small.
Other VIIRS F1 TV Issues 
and Concerns
8
Issue Description Results and Impact
Spikes Large sample spikes in the sensor signal observed for 
few bands during operational mode, only on A-side 
(Redundant) Electronics
No impact. This issue was never observed on Primary Electronics (B-
Side). A plan to correct for this issue is in place. 
Vignetting Observed at FU1 TV Cold functional plateau, but goes 
away when sensor temperature warms up closer to TV 
Cold performance. Vignetting was not noticeable at any 
Performance plateau (Cold, Nominal, Hot).
No impact. Issue is not expected for on-orbit sensortemperatures. 
Program has provided STOP model #6 that includes vignetting compoent. 
This model can be used on orbit for any anomaly simulation and 
mitigation/correction approach if needed. 
Gain bit crosstalk effect Some bands calibration results are showing dependency 
on other bands gain status (High Gain vs Low Gain).
Small impact. This error will be considered in the final calibration error 
budget and impact assessments.
M1 and M11 tail and side 
lobe artifacts
LSF measurements have revealed side lobe features for 
M11 and M1. M11 side lobe might be attributed to field 
stop reflections, and M1 side lobe might  be contributed 
to optical crosstalk. 
Small impact. Need further modeling, to determine impact since on orbit 
illumination will have broad spectrum. It is not known how this side lobe is 
going to be varying on orbit (Ghosting shift if coming from mechanical 
part).
Gain transition noise Increase of radiance non linearity and noise for dual gain 
bands at approximately 10% below Lmax.
No impact. Analysis done and have shown low impact on some EDRs. On-
orbit scenes will be analyzed for impact assessment.
Valuable lessons for future JPSS and DWSS VIIRS Design and Test
VIIRS Polarization Performance
• The polarization testing  
was based on the SIS100 and a 
polarizer sheet.
• A series tests led to high 
quality polarization 
measurements with good 
repeatability.
• The derived polarization 
factors satisfy design 
specifications for sensitivity 
and uncertainty.
• The derived polarization 
factors vary strongly with 
detector and the variability 
depends on the scan angle.  
Good 
Repeatability
VIIRS Response Vs. Scan (RVS)
Pre-Launch Performance
F i t t i n g  U n c e r t ( % )
0 . 0 0
0 . 0 2
0 . 0 4
0 . 0 6
0 . 0 8
0 . 1 0
0 . 1 2
M 1 2 M 1 3 M 1 4 M 1 5 M 1 6 A M 1 6 B I 4 I 5
M9 was impacted by water vapor
RSB Uncertainty : 
Spec = 0.3%
TEB Uncertainty : 
Spec = 0.2%
M9
0.00
0.10
0.20
0.30
0.40
0.50
M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M11 I1 I2 I3
Fitting Uncer (%)
VIIRS F1 TV RSRs (SpMA)
SpMA RSRs vs SIRCUS RSRs
(VisNIR bands only)
SNR and NEdT Performance
13
M3H
M4H
M5H M6
M8 M9
M10
I1
M11
I2
I3
M2H
M1L
M1H
M2L M3L
M4L
M5L
M7H
M7L
M12
M13
M14 M15 M16A M16B
I4
I5
VIIRS Reflective Bands
VIIRS Emissive Bands
On-orbit Calibration and Characterization
• VIIRS post-launch calibration and characterization will be performed 
by the SDR team managed by NOAA STAR with contributions from
– NOAA, NASA, Aerospace, Raytheon, UW, MIT/LL, and NGC
• Calibration strategies and activities have been developed via an 
intensive government-contractor team collaboration, heavily based 
on MODIS lessons and experience; 54 tasks in 6 categories
– Functional Performance and Format Evaluation (FPF 1-7)
– Calibration System Evaluation (CSE 1-6)
– Image Quality Evaluation (IMG 1-4)
– Radiometric Evaluation (RAD 1-25)
– Geometric Evaluation (GEO 1-7)
– Performance and Telemetry Trending (PTT 1-5)
• NASA team will support all phases of NPP VIIRS post-launch 
calibration and characterization
– EOC, ICV, and LTM
L + 50 days
Early Orbit Checkout 
(EOC) Phase
Intensive Calibration 
& Validation (ICV) Phase
Pre-Launch 
Phase
La
un
ch
 
Long Term Monitoring
(LTM) Phase
L + 180 days
Sensor
Characterization
Performance & 
Telemetry Trending
Baseline
SDR Cal/Val
Plan Development
SDR Algorithm
Initialization &
Update Capability
Cal/Val Tool
Development
Functional
Checkout
Data
Inventory
RDR/SDR
Verification
Radiance
Match-Ups
Geolocation
Performance &
Telemetry
Trending
SDR Algorithm
Tuning
SDR 
Parameter
& LUT Updates
Radiance
Match-Ups
Geolocation
Performance &
Telemetry
Trending
SDR 
Parameter
& LUT Updates
VIIRS Cal/Val Activities by Phases
• On-board Calibrators 
– SD and SDSM
– BB
• Lunar Observations: whenever a -55⁰ phase Moon is visible to VIIRS 
(assuming 10/25/11 launch, first opportunity will be day L+71)
• S/C maneuvers
– All planned VIIRS maneuvers have been approved by NPP Project
– Lunar rolls for degradation trending and reflective solar bands stability 
monitoring
– Pitch-up deep space view for thermal emissive bands response vs. scan angle 
(RVS)
– Yaws for SD and SD stability monitor attenuation screen characterization
On-orbit Calibration and Characterization
Tools have been developed and tested to support NPP VIIRS on-orbit 
Cal/Val planning, data analysis, and performance monitoring
On-orbit Calibration and Characterization
MODIS Instrument Temperatures
Blackbody Warm-up and Cool-down
T-MODIS
Wavelength dependent SD degradation
T-MODIS
On-orbit Degradation
A-MODIS
On-orbit Lunar Calibration
Summary
• NPP VIIRS test program at the instrument and observatory level is 
complete and has provided an extensive amount of high quality data 
to enable the assessment of sensor performance
– VIIRS performance exceeds requirements with only a few non-compliances
– Non-compliances have been reviewed and impacts have been assessed.
• On-orbit calibration and characterization plan
– In Integrated Government Team (IGT) has developed a comprehensive cal/val
plan for SDR products to ensure high quality measurements.
– Task leads and support were identified to develop and verify approx. fifty (50) 
on-orbit cal/val tools. We expect full readiness to support NPP Launch.
• Launch readiness testing/rehearsal
– VIIRS cal/val team performed 2 rehearsals to exercise on-orbit cal/val tools 
and processes (July 18-22, August 22-27, 2011).
– Both rehearsal phases were successful, and issues identified are being 
addressed to make sure all components critical to VIIRS cal/val are ready and 
fully verified.
Backup
19
VIIRS F1 Performance Status
Based on sensor level TV testing
Performance Requirement Verification Expected Risk to EDRs
SNR All RSB bands meet SNR specifications with margin Low
M1 and I2 slightly not compliant Low
M8 not compliant Low
Gain Transition Only M1 is not compliant. Margin is about -10% of Lmax. Low
Linearity All RSB bands meet Linearity specification with margin Low
Uniformity 1 NeDL requirement not met for some cases Medium
Uncertainty All bands are meeting specification Low
Stability All RSB bands meet Stability requirements with margin Low
Dynamic Range
Reflective Solar Band (RSB) Performance
Performance Requirement Verification Expected Risk to EDRs
NEdT All TEB bands meet NeDT specifications with margin Low
Dynamic Range All TEB bands compliant for Lmax. Low
Gain Transition Only M13 is slightly not compliant. Low
Linearity All TEB bands meet Linearity specification with margin Low
Uniformity All TEB bands meeting uniformity requirement (1NeDL) Low
Absolute Calibration All TEB bands are meeting specification with margins Low
Stability All TEB bands meet Stability requirements with margin Low
Thermal Emissive Band (TEB) Performance
Performance Requirement Verification Expected Risk to 
Scan DFOV is compliant for majority of M-bands and I-bands. Low
Track IFOV is compliant for all M-Bands and I-bands, Except M12 Det #1. Low
Scan MTF is compliant for majority of M-bands Low
Track MTF is compliant for all M-Bands. Low
Scan HSR is compliant for majority of I-bands Low
Track HSR iscompliant for all I-bands Low
Band to Band Registration (BBR) BBR is compliant for all band pairs, except few cases Low
Pointing Stability Pointing stability is compliant, except daily stability in track direction Low
Spatial Performance
Line Spread Function (LSF)
Performance Requirement Verification Expected Risk to EDRs
Spectral Band Center Only M4 and M16 are slightly not meeting specification Low
Spectral Bandwidth Only M2, M8 and M14 slightly not compliant.
M16A Detectors #5-7 also slightly not compliant
Low
Extended Bandwidth Only I5 is slightly not compliant for the upper 1% limit Low
Integrated Out-Of-Band Many bands are not compliant. However, OOB is well 
characterized
Medium-High
Band to Band Crosstalk Many bands are not compliant. However, crosstalk 
characterization will support on-orbit mitigation.
Medium-High
Spectral RSR Performance
• VIIRS F1 test program is complete and has 
provided good test data to assess sensor 
performance.
• Sensor performance exceeds 
requirements in most cases, and non 
compliances were addressed in waiver 
packages and impact assessments
• NASA performance assessments are 
beginning of life (BOL). Modeling of EOL 
performances are available in Raytheon 
Performance Verification Reports (PVRs). 
• Government team finalized VIIRS F1 
Performance assessments to generate on-
orbit LUTs for SDR algorithm


An Overview of NPP VIIRS Pre-Launch and On-Orbit Calibration and Characterization

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