4-d Digital Camera:4-d Digital Camera:

•

Horizontal:Horizontal: Large area format Focal Plane detector Arrays

Vertical:Vertical: Fourier Transform Spectrometer

Time: Time: Geostationary Satellite

EO-3 “GIFTS”

GGeostationary IImaging FFourier TTransform SSpectrometer

GIFTS - Paving the Way for HESW. P. Menzel and W. L. Smith

The road to HES-IR

VAS (1980-)

GOES Sounder (1994-)

GIFTS (2008-)

(12)

(18)

(~1600)

(~1600)

HES (2012+)

time

VTPR, HIRS (1972, 1978-)

CrIS (2009-)

IASI (2005-)

AIRS (2003-)

HIS (1986-)

IRIS (1969)

(~2400)

(~3600)

IMG (1997)

NAST-I (1998-)

Temperature &Water VaporIR Sounder Staircase

VAS (1980-) –1st Geo Sounder (Spin-Scan)

GIFTS (2008-)

(30)

(1200) HES, GOES-R (2013-)

ITPR,VTPR (1972) / HIRS (1978-)

CrIS / IASI (2006-)

AIRS (2002-)

IRIS / SIRS (1969-70) –1st Sounders

(1200)

(1200/2800)

GOES Sounder (1994-) – (3-Axis)

(1200)

(150-300)

(30)

(30)

Spectral Resolving Power (/ )Resolving Power @ 14 m

BLUE = Leo Purple = Geo

Temperature &Water VaporIR Sounder Staircase

VAS (1980-) –1st Geo Sounder (Spin-Scan)

GIFTS (2008-)

(7-14)

(<10) HES, GOES-R (2013-)

ITPR,VTPR (1972) / HIRS (1978-)

CrIS / IASI (2006-)

AIRS (2002-)

IRIS / SIRS (1969-70) –1st Sounders

(14)

(14/12)

GOES Sounder (1994-) – (3-Axis)

(4)

(160-100/230) nadir only

(30/20-10)

(8)

Spatial Footprint (km)

BLUE = Leo Purple = Geo

GIFTS Sampling CharacteristicsGIFTS Sampling Characteristics• Two 128x 128 Infrared focal plane detector arrays with 4 km footprint size

• One 512 x 512 Visible focal plane detector array with 1 km footprint size

• Field of Regard 512 km x 512 km at satellite sub-point

• Ten second full spectral resolution integration time per Field of Regard

• ~ 80,000 Atmospheric Soundings every minute

GIFTS Overview

• Revolutionary step in observing from GEO

• Designed to deliver 16,000 4-km soundings every 11 sec from spectra at 0.6 cm-1 res.

• Consistent and accurate calibration (< 1K @ 3-sigma)

• Signal-to-noise ratios of several hundred

• Has “raised the bar” for the Hyperspectral Environmental Suite (HES) for GOES-R

GIFTS Sensor Module Technologies

GIFTS to HESGIFTS to HES7 key technology demonstrations (NMP)

Imaging FTS - First real design of geo FTS with adequate S/NLong wave IR detectors – Larger focal plane array enabling much improved coverage rates shown to be feasible (although fabrication not completed ).Active cooling - Long lived compact “mini cooler” paving the way for active cooling, leading to improved performance on GOES-R (fabrication not completed )Light weight optics - Minimizing mass and enhancing thermal stability for improved near local midnight performanceHigh speed Analog to Digital conversion – Required for the fast HES sampling ratesActive Pixel Sensor – Visible detector array enabling sub-pixel cloud detectionStar tracker – Refining pointing control for processing image loops

GIFTS to HESGIFTS to HES

Other technology areas

Laser. Enabling stability for geo- interferometer systems

Calibration. Proper calibration of high-spectral resolution data being demonstrated via internal, high-quality blackbodies.

Processing. Preprocessing to radiances (Level 0 to Level 1) producing soundings and winds (Level 1 to Level 2) defined and processing implications evaluated.

Status of Sensor Module & Test Readiness

• Subsystem CDRs have been conducted and system design is nearly complete

• All key New Millennium technologies will be delivered within months

• System needs to be assembled & tested to prove the thermal/mechanical design and the Imaging FTS enabling technology

• Test Facilities are mainly ready

Predicted SW/ MW NESRincluding photon noises, FPA noises, and ADC noises

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

1500 1700 1900 2100 2300 2500

Wavenumber

mW

/m

2 sr cm

-1

NESR Requirement

1650 - 2250 cm-1Band Edges

Predicted LWIR NESRincluding photon noises, FPA noises, and ADC noises

0.1

0.2

0.3

0.4

0.5

0.6

600 700 800 900 1000 1100 1200

Wavenumber

mW

/m

2 s

r c

m-1

NESR Requirement

685 - 1130 cm-1Band Edges

NESR Goal

Performance Exceeds RequirementPerformance Exceeds Requirement(Noise performance twice as good as required in key regions )(Noise performance twice as good as required in key regions )

Estimate based on measured focal plane array detector and readout performance characteristics

EDU would provide * Demonstration of several key technologies working together (active cooling, FPA, FTS, high speed A/D, lightweight optics, operation at cryogenic temperatures)* Identification of the risks during integration* Characterization of full system (scan mechanism, beam splitter, FPA, cooler, sampling system, fast A/D, reference blackbodies) performance, including

- noise from interferometry- noise from FPA detector and readouts- noise from fast A/D- non-linearities- radiometric and spectral calibration

* Completion will provide many useful lessons as risk reduction for the GOES-R HES

GIFTS Science StatusGIFTS Science Status

Products:Water vapor (soundings, fluxes, winds)

Temperature (sounding, stability)Carbon monoxide concentration (2 Layers)

Ozone concentration (4 Layers)Surface Temperature and emissivity

Clouds (altitude, optical depth, microphysical properties, winds)Aerosol Concentration and Depth

(8.8 to 14.6 microns) (4.4 to 6.1 microns)

ER-2 NAST Data Used to Demonstrate the Accuracy of the GIFTS Wind Measurement Concept (Errors < 4 mps)

0 90 180 270 360Direction (Degrees)

1000

900

800

700

0 4 8 12 16 20

Pre

ssu

re (

mb

)

Speed (mps)

February 11, 2003

36N, 121.6W

GOES - IR

X

Off California Coast

DopplerLIDAR

NAST

December 5, 2003NAST Used to

Demonstrate the Ability to Retrieve

Accurate Soundings Down to Opaque Cloud Levels and Below Optically

Thin Cirrus Cloud

Visible IR

Flight Track Flight Track

Thin Cirrus

Thin Cirrus

Thin Cirrus

GIFTS to HESGIFTS to HESScience areas

Shortwave side of the water vapor band. “Non-traditional" side of water vapor band shown to have advantages for moisture retrievals. Hyperspectral Simulations. Simulations of radiance cubes, for both clear and cloudy skies, helping to develop HES algorithms.Winds tracking in retrievals. Atmospheric motion vectors from inferred by tracking features time sequences of moisture soundings.Soundings in thin cirrus. Demonstrations of soundings in clouds with aircraft hyperspectral data. Education. HES proposals will be better evaluated by experiences and knowledge gained from GIFTS

ConclusionsConclusions• Sensor Module is close to being ready for assembly• Testing Sensor Module in thermal vacuum and

qualifying it for flight would be most valuable• This would validate the Sensor Module thermal

mechanical design, prove the imaging FTSsystem concept, and test other technologies

• Wind profiling measurement concept has been validated using airborne NAST-I data

• NAST-I has also demonstrated that clouds will not severely limit GIFTS sounding capability

• Geo-GIFTS remains very desirable: flight opportunities, including international partnerships, should continue to be explored