# Presentation: 718295

## VIIRS Status to Joint MODIS/VIIRS Science Team

- B. Guenther
- NPOESS SDR (L1) Branch Head
- NPOESS Data Products Division (NDPD)_[bruce.guenther@noaa.gov](mailto:bruce.guenther@noaa.gov)_
- 301 713-4802 or 240 393-1186

- Use For Government Evaluation Purposes only

## Presentation Outline

**VIIRS Management Strategies**
- NDPD organization
- Structure and Schedule of CV Program
**VIIRS Sensor performance Comparisons to MODIS**
- Murphy/Godden Charts
- Still under study for F1 Program
- MODIS – VIIRS overlaps in approaches
**VIIRS Anticipated Caveats**
- EDU Items
- F1 Items

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## VIIRS Management Strategy

- Division Organization
- and
- Structure and Schedule for Calibration and Validation

- Use For Government Evaluation Purposes only

## NPOESS Data Products Division

- VIIRS Lead
- Frank DeLuccia

- CrIS/ATMS
- Gail Bingham

- OMPS Lead
- Scot Janz

- MIS Lead
- Dave Kunkee

**Chief**
**K. St.Germain**
**Deputy (Vacant)**

**NPOESS Data Products Division**

**May 2008**

**Sr. Engineer**
**N. Baker**

**Sr. Advisor - Science**
**R. Murphy (1/2)**

**Sr. Advisor - Operations**
**C. Hoffman**

**Environmental Data Products:**
**C. Hoffman**
**Deputy **
**Vacant**
- Surface & Met : B. Reed
- Atmosphere: H. Kilcoyne
- Cal/Val Planning:  (Vacant)

**Business Support:**
**Godin (IPA)**** **
- GovtTransfers & MOUs (25)
- Contracts COR (6)
- Godin (IPA),  C. Hoffman, B. Guenther (IPA), V. Grano,
- Contract Assoc* J.  Moore
- Docs and Reporting Vacant

**Infrastructure:**
**Capt. V. Gonzalez**
- Interfaces and Design: J. Zajic
- Alg Code and Config: R. Cember, P. Xu
- Tool Development: M. Denning, J. Henson, S. Thomas

**NGST Compliance and Risk Team:**
- V. Grano
- Risk & Coordination: G. Trumbower
- Technical Support: West Coast Aerospace

-  (4) VIIRS
- Sensor Projects

- (15) VIIRS
- Product Projects

- (5) CrIMMS
- Product Projects

- (2)OMPS
- Product Projects

- (1) MIS
- Product Projects

-  (3) CrIMMS
- Sensor Projects

-  (2)OMPS
- Sensor Projects

-  (9) MIS
- Sensor Projects
- (Payloads)

**Sensor Data Products:**
**B. Guenther (IPA)**
**Deputy (Vacant)**

**Admin Support**
**S. Snead**

- B. Thomas
- (Ground)

- M. Ripley,
- T. Johnson
- (Ground)

**NOAA Corp 04**
**J. Adler (On Assignment)**

- (2) X-Cutting Cal/Val Projects

- (2) Projects

- G. Mineart
- (SE)

- G. Mineart
- (SE)

- User Liasons
- (SE)

- IMs
- (Payloads)

**Key interfaces with other divisions are identified by dashed boxes**

- M. Stokes
- Program Control

- GFE:
- SEM, CERES, ATMS
- TSIS (TBD)

## Phases of Cal/ValEvolution of Expertise

| Pre-Launch | RDR Development and Verification | SDR Development and Verification | EDR Development and Verification |
| --- | --- | --- | --- |
| Early Orbit Check-out | RDR On-Orbit Verification | SDR Verification, Tuning, and Initial Validation  | EDR Verification and Initial Validation |
| ICV | Establish Sensor Stability | SDR Validation | EDR Validation |
| LTM | Sensor Long-Term Monitoring | SDR Detailed Validation and Maintenance | EDR Detailed Validation,correc-tion, improvement |

- Phases of Cal/ValEvolution of Expertise

**Sensor Engineers               Users/Scientists**

**Expertise shifts from Contractor Sensor Engineers to Government Customers and Users over time and product chain.**

**TIME**

**PRODUCT**
** ****CHAIN**

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## IPO NPOESS Data Products DivisionCal/Val Discipline Leadership

- IPO NPOESS Data Products DivisionCal/Val Discipline Leadership

**IPO cal/val funded activity for cal/val being led by user community experts**
**NASA, NOAA & DoD communities represented **
- SDR
- VIIRS – Bruce Guenther, IPO
- CRIMMS - Gail Bingham, USU/SDL
- OMPS Sounding Products – Scott Janz, GSFC
- EDR
- VIIRS Atmosphere: David Starr, GSFC
- VIIRS Land: Jeff Privette, NCDC
- VIIRS Ocean: Bob Arnone, NRL
- VIIRS Imagery/Cloud Mask: Tom Kopp, Aerospace, AFWA
**Cal/Val Leads recruit their own teams **
**Cal/Val Leads are developing plans**
**Key near term events**
**Discipline Cal/Val Workshops mostly earlier this year**
**Cal/Val Peer Review (next week)**
**Foster development of Customer/User endorsed Cal/Val Program.**

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## Cal/Val OverviewPlan Development Schedule

- DRAFT

- Cal/Val OverviewPlan Development Schedule

- Major roles for NG in Calibration Core Team, Government oversight, Supplemented by other user and customer agencies

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## Highlights ofVIIRS Senior Science Review Team Report

- Meetings Dates: 27-28 Feb Report Date: 18 March

- Use For Government Evaluation Purposes only

## Overall Comments and Recommendations

**VIIRS appears to an effective sensor**
- Offers much to be excited about even as measured against the performance of MODIS, other heritage sensors.
- SST and Imagery likely within specification on FU1
**Priorities**
- Deliver FU1 on schedule (as close as possible) is HIGH PRIORITY
- Fix unresolved FU1 problems on FU2
- Limit specification compliance concerns to Fields of View within 45 degrees of nadir; edge of scan performance should not drive schedule or cost
- The improved IFA should be inserted into the first flight unit if the schedule opportunity arises - if risk assessment reasonable and experienced staff available

**Senior Science Review (Menzel, Salomonson and Kopp)**

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## Recommendations on FU1 Testing (1 of 2)

| Topic
[not priority ordered] | 
Current Program Status |  |
| --- | --- | --- |
| Polarization Knowledge

Detector specific characterization knowledge is needed to enable image de-striping | In baseline testing program

New testing strategy under development, modeling will be assigned to IPO NRL optics expert for detailed prediction capability |  |
| In-Lab Water Vapor Measurement

1.38 μm band characterization tests require reliable measurement of water vapor amount in lab for correction of test data | Not in baseline testing program,
In Consolidated Customer Consensus

Improvements in measurement strategy (2nd humidity sensor) and implementation included on 19 March recommendations to the Program for added testing |  |
| SWIR Bands Response Uniformity 

Large non-compliance (detector to detector stripes) needs to be resolved | EFR 2384

Is carried as “red” for PER
Root cause not understood |  |

**Senior Science Review (Menzel, Salomonson and Kopp)**

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## Recommendations on FU1 Testing (2 of 2)

| Topic
[not priority ordered] | 
Current Program Status |  |
| --- | --- | --- |
| Common/Different Temp Tests

To separate cal target from sensor cavity effects | Not in baseline testing program, Partly represented  In Consolidated Customer Consensus

Likely needed to close EFR 2386 |  |
| More test data at 82K to support revised FPA set point | Not in baseline testing program, 
In Consolidated Customer Consensus

  Requires some characterization at 82K to sustain the change
  Limited range of scene temperatures now included in test plan, need comprehensive set of scene temperatures in case cooler does not meet at-launch margins |  |
| Feasibility of End to End reflective solar calibration test should be studied | Not in baseline testing program,
Not in Consolidated Customer Consensus

NIST proceeds with source development, expected delivery June 2008.  Schedule considerations will be reviewed at that time. | 
 |

**Senior Science Review (Menzel, Salomonson and Kopp)**

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## VIIRS Sensor Performance in Comparison to MODIS

- Murphy Charts
- Still Under Study for F1 MODIS
-  VIIRS overlaps in approaches
- Follow on upgrades

- Use For Government Evaluation Purposes only

## VisNIR Band Placement and BandWidth for VIIRS and MODIS against background of OC_C Water Leaving Radiance chart

**VIIRS Wavelengths**
**MODIS Wavelengths**
**Line width scaled to bandwidth**
**Line length scaled to horizontal cell size**
**VIIRS I2 and M7 have same center wavelength and bandwidth**

**Atmospheric ozone contribution**

**At Satellite Radiance**

**Rayleigh Scattering Contribution**

- Fluorescence Band

- Reduced band selection reduces sensitivity in coastal waters

**Aerosol Contribution**

**Water-leaving Radiance**

**VIIRS (M)oderate and (I)maging resolution bands numbered consecutively by increasing wavelength.  VisNIR contains M1 .. M7, I1 and I2, Horizontal Cell Size ~ 750m **

**MODIS Vis and NIR focal planes combine to provide B1 & B2 (at 250m resolution NADIR), B3 & B4 (at 500m) and B7 to B16 (at 1000m); 1000m Atmospheric Water Vapor lines  at 905, 936 and 940 nm not matched on VIIRS, not required for VIIRS products and are suppressed here**

**Figure from Evans, adapted by Pratt and adapted further for this work**

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## Comparison of VIIRS SNR in Ocean Color Bands to MODIS and SeaWiFS

- Figure 3  Comparison of VIIRS specified and predicted pixel level SNR adjusted for pixel area, and MODIS, relative to SeaWiFS performance.   From *A Comparison of VIIRS Signal Noise Ratio Performance with SeaWiFS and MODIS*,  by Wayne E. Esaias, October 3, 2004, an unpublished work

**VIIRS measurement capability compares favorably to both MODIS and SeaWiFS when scaled to surface area of measurement, on the condition that VIIRS SNR improves with pixel aggregation as designed.  The MODIS value near 667 nm is a fluorescence band on MODIS that is measured in Time-Delay Integration for an ocean fluorescence product that is not included in the NPOESS product suite and the measurement band is not incorporated into the VIIRS band set.**

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## SWIR Bands on VIIRS and MODIS

***Spectral reflectance signature of a photosynthetically active leaf with a soil signature to show contrast (Tucker and Seller, 1986), as shown in the  MODIS Vegetation Index ATBD by Heute, et. Al. (1999) and adapted for this work***

- Reflectance 0 to 80%

**MODIS SWIR bands are B5, B6 and B7 (at 500m resolution NADIR) and B26 (at 1000m).  Note that B6 on MODIS Aqua failed due to a focal plane defect**

**VIIRS Wavelengths****	****	****	****Line width scaled to bandwidth**
**MODIS Wavelengths****	****	****	****Line length scaled to horizontal cell size**

**VIIRS SWIR bands are I3 and M8, M9, M10 and M11 numbered in increasing wavelength, resolution ~ 750m**

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## MODIS IR bands (in cm-1) shown in context of a line-by-line radiative transfer computation for a U.S. Standard Atmosphere, with VIIRS equivalent bands also indicated.  

**Figure 1**: MODIS infrared spectral response. Nadir viewing emission spectrum of U.S. Standard Atmosphere from LBL-RTM., from MODIS Atmospheric Profile Retrieval ATBD, from S. Seemann, et. al., 2006.

- MODIS IR bands (in cm-1) shown in context of a line-by-line radiative transfer computation for a U.S. Standard Atmosphere, with VIIRS equivalent bands also indicated.

**I5**

**I4**

**M12**

**M13**

**M14**

**M15**

**M16**

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## MODIS To VIIRS Band Selection

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## VIIRS RSB Noise wrt Spec

- https://collab2.st.northropgrumman.com/eRoom/PayloadSensors/VIIRS/0_9dc3b for HSR of I-bands, MTF, BBR and FOV

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## VIIRS TEB Noise wrt Spec

- https://collab2.st.northropgrumman.com/eRoom/PayloadSensors/VIIRS/0_9dc3b  for HSR of I-bands, MTF, BBR and FOV

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## Still Under Study for F1

- Number of testing updates over EDU for F1
- Most significant is additional of second nominal vacuum test plateau
- Polarization testing not yet complete
- Demonstration of radiometric performance mainly in TEB (EFR2386)
- Reduction of stripes in SWIR bands (EFR2384)
- Impact of Dewar ghosting in SWMWIR bands (EFR3326)
- Demonstration of sensor stability through spacecraft TV testing
- Greater control of test analysis process by customer team

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## MODIS–VIIRS Overlaps in Approaches

- NGST will build Core Calibration team
- IPO will provide added Government Team Core Team Members
- Weekly coordination calls (as in MODIS MsWG) to keep Disciplines and Calibration Teams in coordination with representatives for each discipline
- continuity with Atmospheres, Ocean, but not yet Land)
- IPO Projects funding to UWisc, Wolfe, Optics – Walucshka, Xiong/NICST, Minnett, Standards lab measurements of reflectance witness samples, SIS cal via Biggar – including comparisons to APS test source to be performed in next 5 days
*Last Shall be First* and *First Shall be Last* (in detector space)

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## Test Fixture Upgrade Potentials F2 Unit

- NIST developing End-to-End test equipment for SD in-place effective BRDF
- Augmented linearity (bootstrap technique) may be needed
- Improved spectral out of band for VisNIR (expect to demonstrate at NPP spacecraft level) with Traveling Sircus
- Develop scene generator calibrator target

- These items are currently funded or planned for FY09 development at NIST with IPO Project

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## VIIRS Anticipated Caveats

- EDU Items
- F1 Items

- Use For Government Evaluation Purposes only

## Known F1 Items

- VisNIR optical cross-talk
- IFA problem impacts Ocean Color and likely AOT
- Gain switch: noise and linearity
- 3.70 μm (M12), edge detector (#1 in detector-space-TBR on “Bad Detector” list for gain and noise-but still useable)
- Ghosting at detectible level in cooled focal planes – shown effect to be below noise for LWIR in aggregated pixel zones with proxy data, effect in SWMWIR (TBD)
- High spectral out of band component for 0.412 μm (M1) (need to integrate effect in SIS calibrations to  make radiometry work)
- Encourage you here, **and in all cases**, to use full in band and out of band spectral response functions to make analysis work in radiometrically sensitive applications)

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## Another F1 Item, Comments Pls

- 1.246 μm (M8) saturates at 130 W/(m2-sr-μm), and spec set at Lmax of 164.  I think this is OK, and expect to recommend modifying  spec, do you care?

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## Under-performing to Spec, Better MODIS

- Polarization characteristics F1 within spec, but pre-launch characterization knowledge (TBD)
- Scatter characteristics in structured scenes
- SD cavity scatter not measured

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only

## Additional Considerations, Comments

- Fire Product Status
- At best F1 will under-perform MODIS-Aqua
- Will work with UMCP for continuing development
- No solution on horizon for water vapor winds capability
- Sensor design changes (new Non-Recurring Engineering) for F2 to be locked down by ~ July 2008
- BG involved in that process, send me your recommendations (by Discipline Group)

- Presentation to MODIS/VIIRS Science Team,        15 May 2008, B. Guenther for Government Evaluation only