# Presentation: 302090

## Earth Observing - 1

**Stephen Ungar and Dennis Reuter, **
**         **NASA Goddard Space Flight Center
**Jay Pearlman, **TRW
**Donald Lencioni**, MIT Lincoln Laboratory
- 				   June, 1999

**A Pathway to Landsat Continuity and **
**Advanced Spaceborne Spectral Imaging**

## Earth Observing - 1 

- Three revolutionary land imaging
- instruments on EO-1 will collect
- multispectral and hyperspectral
- scenes over the course of the
- EO-1 mission in coordination
- with the Enhanced Thematic
- Mapper (ETM+) on Landsat-7.
- Detailed comparisons of the
- EO-1 and ETM+ images will be
- carried out to validate these
- instruments for  follow-on missions.
- Breakthrough technologies in lightweight materials, high performance                                  integrated detector arrays and precision spectrometers will be                               demonstrated in these instruments.

## EO-1 Mission Highlights

**705 Km altitude Sun-synchronous, circular orbit inclined at 98.2°**
**Descending node with an equatorial crossing about one minute  behind Landsat 7**

**Launch Vehicle: Delta 7320**
**Launch Date: Dec. 1999 **
**Co-manifested with SAC-C**

**ATMOSPHERIC CORRECTOR (AC)**
**Wedge Imaging Spectrometer**

_**W**_**ide-band**
_**A**_**dvanced**
_**R**_**ecorder /**
_**P**_**rocessor**

**X-Band**
**Phased Array**
**Antenna**

**C&DH**
**S-Band**
**Antenna**

**ADVANCED LAND IMAGER (ALI)**
**Multispectral Pushbroom Imager**

**HYPERION**
**Hyperspectral Imaging Spectrometer**

## EO-1 Instrument Overviews

**EO-1 Instrument Overviews**

*  *****  Excludes thermal channel***
***** 35 cm******-1****** constant resolution***

-  3

- 37

## EO-1 Spectral/Spatial Attributes

**              ****Pan**

**              ****MS-1'**

**              ****MS-1**

**              ****MS-2**

**              ****MS-3**

**              ****MS-4**

**              ****MS-4'**

**              ****MS-5'**

**              ****MS-5**

**              ****MS-7**

**Hyperion/VNIR (60 bands)**

**Hyperion/SWIR (160 bands)**

**0.48 – 0.69**

**0.433 – 0.453**

**0.45 – 0.515**

**0.525 – 0.605**

**0.63 – 0.69**

**0.775 – 0.805**

**0.845 – 0.89**

**1.2 – 1.3**

**1.55 – 1.75**

**2.08 – 2.35**

**0.4 – 1.0**

**0.9 – 2.5**

**—**

**—**

**—**

**—**

**—**

**—**

**—**

**—**

**—**

**—**

**10.0**

**10.0**

**      ****10**

**      ****30**

**      ****30**

**      ****30**

**      ****30**

**      ****30**

**      ****30**

**      ****30**

**      ****30**

**      ****30**

**      ****30**

**      ****30**

**Wavelength**

**(μm)**

**  ****Spectral**

**Sampling (nm)**

**       ****Ground Sample**

**      ****Distance (m)**

**Band**

**LEISA AC (256 bands)                0.89 ****– 1****.6****	****              2.8**** – 9.0****	****	****250****	**

## Advanced Land Imager

**ALI Aperture**

## Advanced Land Imager Description

## Advanced Land Imager Overview

**Primary instrument on the first Earth Observing Mission (EO-1) of NASA’s New Millennium Program (NMP)**
**New Millennium Program Goals**
- Reduce costs of future space and Earth science missions
- Increase the quality and quantity of future science missions
- Enable entirely new measurements and science
**EO-1 Advanced Land Imager (ALI)**
- Demonstrates breakthrough technologies
- Flight test will provide high quality land imaging data to validate Landsat data continuity
- Technology transfer will enable lower cost follow-on Landsat instrument

## Advanced Land Imager (ALI)

**SiC Optics**

**Wide FOV**
**1.256° x 15°**

## Main Focal Plane Assembly

**Top View**

**VNIR**

**SWIR**

**MS/Pan SCAs**

**VNIR**

**VNIR**

**VNIR**

**SWIR**

**SWIR**

**SWIR**

**MS/Pan Module**

## EO-1 MS/PAN Spectral Coverage

## MS/PAN Flight Module

**MS/PAN Flight Module**

## ALI Focal Plane Assembly

**ALI Focal Plane Assembly**

## Partially Assembled Flight ALI

-      Telescope features
- 12.5 cm entrance pupil
- 15° x 1.26° field-of-view
- Telecentric,  f/7.5 design
- Unobscured,  reflective optics
- Silicon carbide mirrors
- Wavefront error = 0.11 RMS @ 633 nm

## ALI Flight Instrument

## Installation of ALI into Thermal Vacuum Chamber

## Image Reconstruction and Calibration MS Band 1

**Reconstructed Raw Image**

**“****Calibrated” Image**

## Solar Calibration

**Solar Calibration**

**1%**

**1%**

**2%**

**3%**

**7%**

**10%**

**20%**

**30%**

**20%**

**50%**

**20%**

**70%**

**20%**

**90%**

**2.5"**

**2.5"**

**Signal**

**Level**

**  ****Cumulative**

**  ****Signal**

## ALI SNR Performance

**@ 5% Earth Surface Reflectance**

## Growth Path to Advanced Landsat 

**Populate focal plane with 5 MS/PAN modules**
- Full 185 km wide field-of-view
- Main Focal Plane bench designed for 5 modules
**Changes required to accommodate full MS/PAN coverage**
- _Resource__	__	_       _ALI__	__	_         _Advanced Landsat_
- Data Ports		        1		 	        5
- Data Rate		102.4 Mb/s		 512 Mb/s
- FPE Power	 ~ 15 Watts		~ 50 Watts
- FPA Size	      	30.7 x 6.6 x 5.2 cm	30.7 x 6.6 x 5.2 cm
**Summary**
- No significant physical changes for full Landsat coverage focal plane

**Growth Path to Advanced Landsat **
**Type Instrument**

## Landsat Instrument Comparison

**Landsat Instrument Comparison**

***ALI Based Concept for Future Landsat Instrument***

**	****100****	****Mass (kg)****	****425**
**	****100****	****Power (W)****	****545**
**	****0.2****	****Size (m****3****)****	****1.4**
**	****80**X**50**X**50****	****Size (cm)****	****196**X**114**X**66**
**	****10****	****VNIR / SWIR Bands****	****7**
**	****6200****	****Detectors Per Band****	****16**
**	****None****	****Thermal Bands****	****1**
**	****400****	****Data Rate (Mbps)****	****150**
**	****10****	****Pan Resolution (m)****	****15**
**	****4****	****Relative SNR****	****1**

## EO-1 Instrument Overviews

*  *****  Excludes thermal channel***
***** 35 cm******-1****** constant resolution***

- Hyperspectral Analysis derives from the use of contiguous spectral channels, allowing the use of derivatives and sophisticated analysis techniques. The large number of bands allows more complex systems to be addressed without the under sampling inherent in multispectral systems.

- 37

- 3

## Hyperion Imaging Spectrometer

**Convex Grating spectrometers with CCD VNIR and HgCdTe SWIR detectors (60μm pixels)**
**30m spatial and 10nm spectral resolutions over 7.5km swath and 400-2500nm spectral range**
**Multiple calibration options: lamps, lunar, solar, ground imaging and laboratory**
**Hyperspectral Imaging Capability to address Earth Science oriented community**

## Hyperion Optical System

**Grating Spectrometer**

**Telescope**

## Hyperion in Vacuum Chamber

**Hyperion**

- Ground
- Support
- Equipment

## Hyperion S/N Performance Prediction

- Mid latitude, 30% albedo

## LEISA Atmospheric Corrector

**Correction of multispectral surface imagery for atmospheric variability (water and aerosols).**
**High spectral, moderate spatial resolution (250m), large swath (180km) hyperspectral imager using wedge filter technology**
**Spectral coverage of 0.89 - 1.6μm, bands selected for optimal correction of high spatial resolution images.**

## AC Triple Sensor System

**Atmospheric Corrector has three independent sensors to cover 180km swath**

**Solar Illumination input provides calibration**

## EO-1 and Landsat

**Less Than 1 Minute**

**Landsat ETM+ Multispectral Swath Coverage**
**(185 km @ 30 m)**

**705 km Altitude**

**AVIRIS Underflight**
**(10 km @ 20 m)**

**ALI Multispectral**
**Swath Coverage**
**(37 km @ 30 m)**

**Atmospheric Corrector Hyperspectral Coverage (185 km @ 125 / 250 m)**

**Hyperion**
**Hyperspectral Swath Coverage**
**(7.5 km @ 30 m)**

- Landsat-7

- EO-1

**TRWIS Underflight ****(FOV varies      with altitude****)**

**EO-1 and Landsat**

## EO-1 and Landsat 7 Descending Orbit Ground Tracks

**EO-1 and Landsat 7 Descending Orbit Ground Tracks**

**N**

*Landsat 7*
*ETM+*

*EO-1*
*ALI*

*EO-1*
*Atmospheric*
*Corrector*

*EO-1*
*Hyperion*