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Nanosatellites for Earth environmental monitoring: the MicroMAS project

Summary

The Micro-sized Microwave Atmospheric Satellite (MicroMAS) is a 3U cubesat (34x10x10 cm, 4.5 kg) hosting a passive microwave spectrometer operating near the 118.75-GHz oxygen absorption line. The focus of the first MicroMAS mission (hereafter, MicroMAS-1) is to observe convective thunderstorms, tropical cyclones, and hurricanes from a near-equatorial orbit at approximately 500-km altitude. A MicroMAS flight unit is currently being developed in anticipation of a 2014 launch. A parabolic reflector is mechanically rotated as the spacecraft orbits the earth, thus directing a cross-track scanned beam with FWHM beamwidth of 2.4-degrees, yielding an approximately 20-km diameter footprint at nadir incidence from a nominal altitude of 500 km. Radiometric calibration is carried out using observations of cold space, the earth?s limb, and an internal noise diode that is weakly coupled through the RF front-end electronics. A key technology feature is the development of an ultra-compact intermediate frequency processor module for channelization, detection, and A-to-D conversion. The antenna system and RF front-end electronics are highly integrated and miniaturized. A MicroMAS-2 mission is currently being planned using a multiband spectrometer operating near 118 and 183 GHz in a sunsynchronous orbit of approximately 800-km altitude. A HyMAS- 1 (Hyperspectral Microwave Atmospheric Satellite) mission with approximately 50 channels near 118 and 183 GHz is also being planned. In this paper, the mission concept of operations will be discussed, the radiometer payload will be described, and the spacecraft subsystems (avionics, power, communications, attitude determination and control, and mechanical structures) will be summarized.
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Summary

The Micro-sized Microwave Atmospheric Satellite (MicroMAS) is a 3U cubesat (34x10x10 cm, 4.5 kg) hosting a passive microwave spectrometer operating near the 118.75-GHz oxygen absorption line. The focus of the first MicroMAS mission (hereafter, MicroMAS-1) is to observe convective thunderstorms, tropical cyclones, and hurricanes from a near-equatorial orbit at approximately...

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Convection diagnosis and nowcasting for oceanic aviation applications

Published in:
Proc. SPIE, Vol. 7088, Remote Sensing Applications for Aviation Weather Hazard Detection and Decision Support, 25 August 2008, 708808.

Summary

An oceanic convection diagnosis and nowcasting system is described whose domain of interest is the region between the southern continental United States and the northern extent of South America. In this system, geostationary satellite imagery are used to define the locations of deep convective clouds through the weighted combination of three independent algorithms. The resultant output, called the Convective Diagnosis Oceanic (CDO) product, is independently validated against space-borne radar and lightning products from the Tropical Rainfall Measuring Mission (TRMM) satellite to ascertain the ability of the CDO to discriminate hazardous convection. The CDO performed well in this preliminary investigation with some limitations noted. Short-term, 1-hr and 2-hr nowcasts of convection location are performed within the Convective Nowcasting Oceanic (CNO) system using a storm tracker. The CNO was found to have good statistical performance at extrapolating existing storm positions. Current work includes the development and implementation of additional atmospheric features for nowcasting convection initiation and to improve nowcasting of mature convection evolution.
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Summary

An oceanic convection diagnosis and nowcasting system is described whose domain of interest is the region between the southern continental United States and the northern extent of South America. In this system, geostationary satellite imagery are used to define the locations of deep convective clouds through the weighted combination of...

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Hyperspectral environmental suite for the Geostationary Operational Environmental Satellite (GOES)

Published in:
SPIE Vol. 5425, Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery X, 12-15 April 2004, pp. 329-340.

Summary

The GOES satellites will fly a Hyperspectral Environmental Suite (HES) on GOES-R in the 2012 timeframe. The approximately 1500 spectral channels (technically ultraspectral), leading to improved vertical resolution, and approximately five times faster coverage rate planned for the sounder in this suite will greatly exceed the capabilities of the current GOES series instrument with its 18 spectral channels. In the GOES-R timeframe, frequent measurements afforded by geostationary orbits will be critical for numerical weather prediction models. Since the current GOES soundings are assimilated into numerical weather prediction models to improve the validity of model outputs, particularly in areas with little radiosonde coverage, this hyperspectral capability in the thermal infrared will significantly improve sounding performance for weather prediction in the western hemisphere, while providing and enhancing other products. Finer spatial resolution is planned for mesoscale observation of water vapor variations. The improvements over the previous GOES sounders and a primary difference from other planned instruments stem from two-dimensional focal plane array availability. These carry an additional set of challenges in terms of instrument specifications, which will be discussed. As a suite, HES is planned with new capabilities for coastal ocean coverage with the goal of including open ocean coverage. These new planned imaging applications, which will be either multispectral or hyperspectral, will also be discussed.
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Summary

The GOES satellites will fly a Hyperspectral Environmental Suite (HES) on GOES-R in the 2012 timeframe. The approximately 1500 spectral channels (technically ultraspectral), leading to improved vertical resolution, and approximately five times faster coverage rate planned for the sounder in this suite will greatly exceed the capabilities of the current...

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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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GLONASS performance in 1992: a review

Published in:
GPS World, Vol. 4, No. 5, May 1993, pp. 28-39.

Summary

Researchers at MIT's Lincoln Laboratory reviewed GLONASS developments during 1992, focusing on the requirements of civil aviation and the issues related to position estimation. The results show that the overall performance remains substantially the same as observed in 1991.
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Summary

Researchers at MIT's Lincoln Laboratory reviewed GLONASS developments during 1992, focusing on the requirements of civil aviation and the issues related to position estimation. The results show that the overall performance remains substantially the same as observed in 1991.

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Integrated use of GPS and GLONASS in civil aviation navigation I: coverage and data models

Published in:
Institute of Navigation, 3rd Int. Technical Mtg. of the Satellite Division, 19-21 September 1990, pp. 425-435.

Summary

Pursuant to a bilateral agreement signed in 1988, both US and USSR are currently in the process of examining integrated use of GPS and GLONASS for sole-means civil aviation navigation. This paper presents results from the initial phase of a program underway at MIT Lincoln Laboratory to support this effort. Specifically, we present results on satellite coverage and quality of the range measurements from GPS and GLONASS. The coverage results highlight the extent to which each system alone falls short of providing a self-contained system integrity check. In integrated use, however, there are enough redundant measurements to make receiver autonomous integrity monitoring (RAIM) practical. The data quality results are based on statistical analysis of the range measurements from GPS, at various levels of selective availability (SA), collected over extended periods. We present empirical cumulative distribution function of the range error, and RMS value of its component, defined as the 'effective' range error, relevant to position estimation. These results are used to project the position estimation. These results are used to project the position estimation accuracy achievable globally with GPS, when operational. Comparable results for GLONASS are being developed. The coverage and data quality results together provide a basis for development of the navigation and RAIM algorithms for the integrated use. This will be addressed in the next phase of the program. The important considerations in the design of these algorithms, including the differences in the reference systems for space and time employed by the two systems, are briefly reviewed.
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Summary

Pursuant to a bilateral agreement signed in 1988, both US and USSR are currently in the process of examining integrated use of GPS and GLONASS for sole-means civil aviation navigation. This paper presents results from the initial phase of a program underway at MIT Lincoln Laboratory to support this effort...

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Effects of common band (3500-3700 MHz) operation of geostationary satellites and the FAA limited-surveillance radar

Author:
Published in:
MIT Lincoln Laboratory Report ATC-92

Summary

The study reported investigates the likelihood of interference by FDM/FM transmissions from geostationary satellites operating in the frequency range 3500-3700 MHz upon proposed FAA limited-surveillance radars operating in the same band. It is concluded, based upon the analysis, that the FAA limited-surveillance radars and the geostationary satellites can function in a common band, 3500-3700 MHz with only slight degradation to the radar coverage.
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Summary

The study reported investigates the likelihood of interference by FDM/FM transmissions from geostationary satellites operating in the frequency range 3500-3700 MHz upon proposed FAA limited-surveillance radars operating in the same band. It is concluded, based upon the analysis, that the FAA limited-surveillance radars and the geostationary satellites can function in...

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Improved satellite constellations for CONUS ATC coverage

Author:
Published in:
MIT Lincoln Laboratory Report ATC-23

Summary

This report examines the problem of designing a constellation of orbiting satellites capable of supporting an aircraft navigation/surveillance service over CONUS. It is assumed that the aircraft positions are determined by hyperbolic multilateration using all satellites visible at elevation angles exceeding a minimum angle. Comprehensive analyses are presented of three "baseline" constellations. The constellations are representative of previous large, medium, and small constellations. The analyses include calculation of The Geometric Dilution of Precision (GDOP) during level flight, calculation of GDOP after a key satellite is deleted, and calculation of GDOP during aircraft banking. Comparison of the resulting GDOP's with the theoretical minimum values indicates that there is considerable room for improvement. A new method of calculating GDOP is described. The method suggests that improved GDOP's can be obtained by placing satellites in retrograde orbits rather than the previous posigrade orbits. Accordingly, nine new constellations are designed that employ retrograde orbits. When subjected to the same analyses as the baseline constellations, the new constellations exhibit significantly improved GDOP's.
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Summary

This report examines the problem of designing a constellation of orbiting satellites capable of supporting an aircraft navigation/surveillance service over CONUS. It is assumed that the aircraft positions are determined by hyperbolic multilateration using all satellites visible at elevation angles exceeding a minimum angle. Comprehensive analyses are presented of three...

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