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Design of an optical photon counting array receiver system for deep-space communications

Summary

Demand for increased capacity in deep-space to Earth communications systems continues to rise as sensor data rates climb and mission requirements expand. Optical freespace laser communications systems offer the potential for operating at data rates 10 to 1000 times that of current radiofrequency systems. A key element in an optical communications system is the Earth receiver. This paper reviews the design of a distributed photon-counting receiver array composed of four meter-class telescopes, developed as a part of the Mars Laser Communications Demonstration (MLCD) project. This design offers a cost-effective and adaptable alternative approach to traditional large, single-aperture receive elements while preserving the expected improvement in data rates enabled by free-space laser communications systems. Key challenges in developing distributed receivers and details of the MLCD design are discussed.
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Summary

Demand for increased capacity in deep-space to Earth communications systems continues to rise as sensor data rates climb and mission requirements expand. Optical freespace laser communications systems offer the potential for operating at data rates 10 to 1000 times that of current radiofrequency systems. A key element in an optical...

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Summary of the EO-1 ALI performance during the first 2.5 years on-orbit

Published in:
SPIE Vol. 5151, Earth Observing Systems VIII, 3-8 August 2003, pp. 574-585.

Summary

The Advanced Land Imager (ALI) is a VNIR/SWIR, pushbroom instrument that is flying aboard the Earth Observing-1 (EO-1) spacecraft. Launched on November 21, 2000, the objective of the ALI is to flight validate emerging technologies that can be infused into future land imaging sensors. During the first two and one-half years on-orbit, the performance of the ALI has been evaluated using on-board calibrators and vicarious observations. The results of this evaluation are presented here. The spatial performance of the instrument, derived using stellar, lunar, and bridge observations, is summarized. The radiometric stability of the focal plane and telescope, established using solar, lunar, ground truth, and on-board sources, is also provided.
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Summary

The Advanced Land Imager (ALI) is a VNIR/SWIR, pushbroom instrument that is flying aboard the Earth Observing-1 (EO-1) spacecraft. Launched on November 21, 2000, the objective of the ALI is to flight validate emerging technologies that can be infused into future land imaging sensors. During the first two and one-half...

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Overview of the Earth Observing One (EO-1) mission

Published in:
IEEE Trans. Geosci. Remote Sens., Vol. 41, No. 6, Pt. 1, June 2003, pp. 1149-1159.

Summary

The Earth Observing One (EO-1) satellite, a part of National Aeronautics and Space Administration's New Millennium Program, was developed to demonstrate new technologies and strategies for improved earth observations. It was launched from Vandenburg Air Force Base on November 21, 2000. The EO-1 satellite contains three observing instruments supported by a variety of newly developed space technologies. The Advanced Land Imager (ALI) is a prototype for a new generation of Landsat-7 Thematic Mapper. The Hyperion Imaging Spectrometer is the first high spatial resolution imaging spectrometer to orbit the earth. The Linear Etalon Imaging Spectral Array (LEISA) Atmospheric Corrector (LAC) is a high spectral resolution wedge imaging spectrometer designed to measure atmospheric water vapor content. Instrument performances are validated and carefully monitored through a combination of radiometric calibration approaches: solar, lunar, stellar, earth (vicarious), and atmospheric observations complemented by onboard calibration lamps and extensive prelaunch calibration. Techniques for spectral calibration of space-based sensors have been tested and validated with Hyperion. ALI and Hyperion instrument performance continue to meet or exceed predictions well beyond the planned one-year program. This paper reviews the EO-1 satellite system and provides details of the instruments and their performance as measured during the first year of operation. Calibration techniques and tradeoffs between alternative approaches are discussed. An overview of the science applications for instrument performance assessment is presented.
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Summary

The Earth Observing One (EO-1) satellite, a part of National Aeronautics and Space Administration's New Millennium Program, was developed to demonstrate new technologies and strategies for improved earth observations. It was launched from Vandenburg Air Force Base on November 21, 2000. The EO-1 satellite contains three observing instruments supported by...

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Flight test results of the Earth Observing-1 Advanced Land Imager

Published in:
SPIE, Vol. 4814, Earth Observing Systems VII, 7-10 July 2002, pp. 296-305.

Summary

The Advanced Land Imager (ALI) is the primary instrument on the Earth Observing-1 spacecraft (EO-1) and was developed under NASA's New Millennium Program (NMP). The NMP mission objective is to flight-validate advanced technologies that will enable dramatic improvements in performance, cost, mass, and schedule for future, Landsat-like, Earth Science Enterprise instruments. ALI contains a number of innovative features designed to achieve this objective. These include the basic instrument architecture, which employs a push-broom data collection mode, a wide field-of-view optical design, compact multi-spectral detector arrays, non-cryogenic HgCdTe for the short wave infrared bands, silicon carbide optics, and a multi-level solar calibration technique. The sensor includes detector arrays that operate in ten bands, one panchromatic, six VNIR and three SWIR, spanning the range fiom 0.433 to 2.35 um. Launched on November 21, 2000, ALI instrument performance was monitored during its first year on orbit using data collected during solar, lunar, stellar, and earth observations. This paper will provide an overview of EO-1 mission activities during this period. Additionally, the on-orbit spatial and radiometric performance of the instrument will be compared to pre-flight measurements and the temporal stability of ALI will be presented.
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Summary

The Advanced Land Imager (ALI) is the primary instrument on the Earth Observing-1 spacecraft (EO-1) and was developed under NASA's New Millennium Program (NMP). The NMP mission objective is to flight-validate advanced technologies that will enable dramatic improvements in performance, cost, mass, and schedule for future, Landsat-like, Earth Science Enterprise...

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Initial flight test results from the EO-1 Advanced Land Imager: radiometric performance

Published in:
IGARSS 2001, Int. Geoscience and Remote Sensing Symp., Vol. 1, 9-13 July 2001, pp. 515-417.

Summary

The Advanced Land Imager (ALI) is one of three instruments flown on the first Earth Observing mission (EO-1) under NASA's New Millennium Program (NMP). The primary NMP mission objective is to flight-validate advanced technologies that will enable dramatic improvements in performance, cost, mass and schedule for future, Landsat-like, earth remote sensing instruments. ALI contains a number of innovative features, including all the Category 1 technology demonstrations of the EO-1 mission. These include the basic instrument architecture which employs a push-broom data collection mode, a wide field of view optical design, compact multispectral detector arrays, non-cryogenic HgCdTe for the short wave infrared bands, silicon carbide optics and a multi-level solar calibration technique. The Earth Observing-1 spacecraft was successfully launched on November 21, 2000. During the first sixty days on orbit, several Earth scenes were collected and on-orbit calibration techniques were exercised by the Advanced Land Imager. This paper presents the status of ALI radiometric performance characterization obtained from the data collected during that period.
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Summary

The Advanced Land Imager (ALI) is one of three instruments flown on the first Earth Observing mission (EO-1) under NASA's New Millennium Program (NMP). The primary NMP mission objective is to flight-validate advanced technologies that will enable dramatic improvements in performance, cost, mass and schedule for future, Landsat-like, earth remote...

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EO-1 Advanced Land Imager in-flight calibration

Published in:
SPIE, Vol. 3439, Earth Observing Systems III, 19-21 July 1998, pp. 416-422.

Summary

The EO-1 Advanced Land Imager (ALI) is the first earth-orbiting instrument to be flown under NASA's New Millenium program. The ALI employs novel wide-angle optics and a multispectral and panchromatic spectrometer. EO-1 is a technology verification project designed to demonstrate comparable or improved Landsat spatial and spectral resolution with substantial mass, volume, and cost savings. This paper provides an overview of in-flight calibration and performance assessment of the Advanced Land Imager. Included are techniques for calibrating and assessing focus and MTF using long, straight, man-made objects and monitoring of radiometric linearity and offsets using an internal calibration source, standard Earth reference scenes, and solar and lunar observations.
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Summary

The EO-1 Advanced Land Imager (ALI) is the first earth-orbiting instrument to be flown under NASA's New Millenium program. The ALI employs novel wide-angle optics and a multispectral and panchromatic spectrometer. EO-1 is a technology verification project designed to demonstrate comparable or improved Landsat spatial and spectral resolution with substantial...

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