Mr. Aiman Al-hajjah Profile

Aiman Al-hajjah

at Science Applications International Corp

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Author

Publications (14)

Proceedings Article | 24 February 2004 Paper

Calibrations of the Clouds and the Earth’s Radiant Energy System (CERES) instruments on the Terra and Aqua spacecrafts

Aiman Alhajjah, Dhirendra Pandey, Jack Paden, Kory Priestley, Robert Lee, Robert Wilson, Susan Thomas

Proceedings Volume 5232, (2004) https://doi.org/10.1117/12.511527

KEYWORDS: Calibration, Shortwaves, Sensors, Space operations, Lamps, Photodiodes, Black bodies, Silicon, Instrument modeling, Data modeling

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Proceedings Article | 16 February 2004 Paper

Twelve-month running trends from Earth Radiation Budget Satellite (ERBS) active-cavity radiometric measurements and global surface temperatures

Dhirendra Pandey, Robert Lee, Jack Paden, Kathryn Bush, Dianne Snyder, Robert Wilson, Waldena Banks, Aiman Al-Hajjah, Susan Thomas

Proceedings Volume 5235, (2004) https://doi.org/10.1117/12.511231

KEYWORDS: Satellites, Radiometry, Shortwaves, Sensors, Data centers, Temperature metrology, Calibration, Climatology, Climate change, Space operations

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Proceedings Article | 10 November 2003 Paper

A comprehensive radiometric validation protocol for CERES Earth Radiation Budget climate record sensors

Kory Priestley, Susan Thomas, Peter Spence, Z. Szewczyk, Edward Kizer, Dale Walikainen, Aiman Al-Hajjah, Robert Wilson

Proceedings Volume 5151, (2003) https://doi.org/10.1117/12.507520

KEYWORDS: Calibration, Sensors, Optical filters, Shortwaves, Clouds, Space operations, Instrument modeling, Environmental sensing, Climatology, Error analysis

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Proceedings Article | 10 November 2003 Paper

On-orbit solar calibrations using the Aqua Clouds and Earth's Radiant Energy System (CERES) in-flight calibration system

Robert Wilson, Robert Lee, Jack Paden, Dhirendra Pandey, Kory Priestley, Susan Thomas, Aiman Al-Hajjah

Proceedings Volume 5151, (2003) https://doi.org/10.1117/12.507526

KEYWORDS: Calibration, Sensors, Shortwaves, Solar energy, Sun, Bolometers, Diffusers, Space operations, Radiometry, Solar radiation

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Proceedings Article | 10 November 2003 Paper

Measurements of filtered lunar radiances using the NASA Terra spacecraft/CERES thermistor bolometer sensors during 2000 and 2001

Robert Lee, George Smith, Zbigniew Szewczyk, David Kratz, Kory Priestley, Susan Thomas, Kathryn Bush, Jack Paden, Dhirendra Pandey, Robert Wilson, Aiman Al-Hajjah

Proceedings Volume 5151, (2003) https://doi.org/10.1117/12.508333

KEYWORDS: Sensors, Shortwaves, Bolometers, Space operations, Calibration, Temperature metrology, Solids, Black bodies, Clouds, Instrument modeling

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Studies were conducted to define lunar radiances on an absolute radiometric scale tied to the International Temperature Scale of 1990 (ITS-90). The Clouds and the Earth's Radiant Energy System (CERES) thermistor bolometer sensor instruments were used to measure lunar radiances from the NASA Tropical Rainfall Measuring Mission (TRMM), Terra, and Aqua spacecraft platforms. Each CERES instrument package consisted of three different sensors: (1) broadband shortwave [0.3 to 5 micrometers]; (2) broadband total [0.3 to >100 micrometers]; and (3) narrowband, water vapor window [8 to 12 micrometers]. Moon-reflected solar radiances were measured with the shortwave sensor while both moon-reflected solar and moon-emitted longwave radiances were measured using the total sensor. The differences between the total and shortwave sensor measurements were used to determine the broadband longwave, moon-emitted radiances. The narrowband, water vapor window sensor measured only the longwave, moon-emitted radiances. The radiances were obtained as a function of phase angle (formed at the moon between directions to the sun and the spacecraft). The resulting filtered radiances were normalized to the mean sun-moon distance, one astronomical unit (AU), and to the mean earth-moon distance of 0.0026 AU (384,400 kilometers). 1998, 2000, and 2001, CERES lunar filtered measurements are presented, compared, and analyzed. Additional measurements are presented from the January 9, 2001, and May 16, 2003, total lunar eclipse events. Analyses of the Clouds and the Earth's Radiant Energy System (CERES) thermistor bolometer sensor observations of lunar radiances indicated that broadband shortwave and longwave lunar filtered radiances can be linked to a radiometric scale based upon an International Temperature Scale of 1990 (ITS-90) at absolute levels approaching ± 0.2 Wm^-2sr^-1. For a lunar image diameter of 31 minutes of arc, an emitting lunar disc temperature of approximately 400 Kelvin was estimated from the longwave radiances near 7-degree phase angle. The integration of the CERES unfiltered radiances over all reflection angles can be used to define the moon radiation budget (MRB).

Proceedings Article | 14 March 2003 Paper

Performance studies of CERES sensors on Earth Science Enterprise (ESE) Terra mission using onboard calibrations and other validation methods

Susan Thomas, Kory Priestley, Robert Lee, Peter Spence, Robert Wilson, Aiman Al-Hajjah, Jack Paden, Dhirendra Pandey

Proceedings Volume 4886, (2003) https://doi.org/10.1117/12.462968

KEYWORDS: Sensors, Shortwaves, Calibration, Black bodies, Mirrors, Bolometers, Space operations, Sensor calibration, Diffusers, Space telescopes

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Clouds and the Earth's Radiant Energy system (CERES) sensors provide accurate measurements for the long-term monitoring of the Earth's radiation budget components such as reflected shortwave and emitted longwave radiances. CERES instruments has three scanning thermistor bolometers that measure broadband radiances in the shortwave (0.3 to 5.0 micrometer), total (0.3 to >100 micrometer) and in 8 - 12 micrometer water vapor window regions. Two of the CERES instruments (Flight Models 1 and 2(FM1&2)) are part of ESE Terra mission and has been successfully making Earth radiance measurements for the past two years. The CERES sensors are calibrated in flight using the on-board blackbody sources and a tungsten lamp known as internal calibration module (ICM) as well as a solar diffuser plate known as the Mirror Attenuator Mosaic (MAM). The ICM calibrations is used to determine the sensor measurement precisions during the ground, ground to orbit, and the on-orbit phases of the sensor calibrations. The MAM calibrations define on-orbit shifts or drifts in shortwave and total sensor responses. The traditional validation studies conducted to understand the stability of the sensors' performance include the analysis of Tropical Mean (TM) value using nadir tropical ocean measurements and three channel intercomparison between sensors of the same instrument. With two CERES instruments on the same platform, an additional study utilizing direct comparison of similar sensor measurements viewing the same geolocation is also conducted. The ICM results have shown that total sensors on both instruments have shown a variation of 0.25 and 0.5 percent respectively, whereas the shortwave sensors show a minimal change of 0.2 percent each. With high variability during the initial year, the MAM results have stabilised within the 0.5 percent precision range in the second year. The validation studies have shed additional light into the behaviour of total sensors in the shortwave and longwave spectral regions. The TM longwave day night difference (DN) derived from longwave sensors of each CERES instrument indicate that the FM1 sensors have varied about 0.25 watts m^-2sr^-1, whereas the total sensor in FM2 has a gradual rise of 1.4 watts m^-2sr^-1 in a 30 month period. This paper discusses briefly the contribution of each calibration and validation study in understanding the CERES sensors' behavior and the results from both Terra instruments' sensors. It also discusses how the various analyses are put together in understanding the rise seen in the total sensor of FM2 instrument.

Proceedings Article | 21 February 2001 Paper

Relationship between the Clouds and the Earth's Radiant Energy System (CERES) measurements and surface temperatures of selected ocean regions

Dhirendra Pandey, Robert Lee, Shannon Brown, Jack Paden, Peter Spence, Susan Thomas, Robert Wilson, Aiman Al-Hajjah

Proceedings Volume 4150, (2001) https://doi.org/10.1117/12.416957

KEYWORDS: Optical filters, Shortwaves, Satellites, Clouds, Temperature metrology, Sensors, Calibration, Bolometers, Sensor calibration, Space telescopes

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Proceedings Article | 15 November 2000 Paper

Determination and validation of slow mode coefficients of the Clouds and the Earth's Radiant Energy System (CERES) scanning thermistor bolometers

G. Louis Smith, Dhirendra Pandey, Peter Spence, Kory Priestley, Bruce Barkstrom, Robert Lee, Jack Paden, Susan Thomas, Robert Wilson, Aiman Al-Hajjah

Proceedings Volume 4135, (2000) https://doi.org/10.1117/12.494226

KEYWORDS: Sensors, Calibration, Shortwaves, Bolometers, Black bodies, Space operations, Clouds, Instrument modeling, Aerospace engineering, Fermium

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Proceedings Article | 15 November 2000 Paper

Clouds and the Earth's Radiant Energy System (CERES) spectral response characterizations

Aiman Al-Hajjah, Kory Priestley, Susan Thomas, Robert Lee, Bruce Barkstrom, Jack Paden, Dhirendra Pandey, Robert Wilson

Proceedings Volume 4135, (2000) https://doi.org/10.1117/12.494240

KEYWORDS: Sensors, Shortwaves, Fourier transforms, Calibration, Optical filters, Mirrors, Reflectivity, Clouds, Signal detection, Planets

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Proceedings Article | 15 November 2000 Paper

On-orbit solar calibrations using the Terra Clouds and Earth's Radiant Energy System (CERES) in-flight calibration system

Robert Wilson, Robert Lee, Bruce Barkstrom, Jack Paden, Dhirendra Pandey, Kory Priestley, G. Louis Smith, Susan Thomas, Aiman Al-Hajjah

Proceedings Volume 4135, (2000) https://doi.org/10.1117/12.494223

KEYWORDS: Calibration, Shortwaves, Sensors, Sun, Radiometry, Solar energy, Bolometers, Diffusers, Space operations, Solar radiation

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Proceedings Article | 15 November 2000 Paper

Terra spacecraft CERES flight model 1 and 2 sensor measurement precisions: ground-to-flight determinations

Robert Lee, Kory Priestley, Bruce Barkstrom, Susan Thomas, Aiman Al-Hajjah, Jack Paden, Dhirendra Pandey, Robert Wilson, G. Louis Smith

Proceedings Volume 4135, (2000) https://doi.org/10.1117/12.494216

KEYWORDS: Sensors, Calibration, Shortwaves, Black bodies, Lamps, Space operations, Environmental sensing, Sensor calibration, Chlorine, Photodiodes

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Proceedings Article | 17 July 2000 Paper

Early trends of the Clouds and the Earth's Radiant Energy System (CERES) instrument's performance using in-flight calibration sources for the Earth Science Enterprise (ESE) TERRA mission

Susan Thomas, Robert Lee, Kory Priestley, Bruce Barkstrom, Aiman Al-Hajjah, Robert Wilson, Jack Paden, Dhirendra Pandey

Proceedings Volume 4030, (2000) https://doi.org/10.1117/12.391785

KEYWORDS: Calibration, Sensors, Black bodies, Shortwaves, Bolometers, Space operations, Sensor calibration, Lamps, Clouds, Earth sciences

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Proceedings Article | 28 December 1999 Paper

Ground through on-orbit transfer of the International Temperature Scale of 1990 (ITS-90): radiometeric scale using the CERES thermistor bolometers and built-in flight calibration systems

Robert Lee, Susan Thomas, Robert Wilson, Kory Priestley, Jack Paden, Dhirendra Pandey, Aiman Al-Hajjah

Proceedings Volume 3870, (1999) https://doi.org/10.1117/12.373207

KEYWORDS: Sensors, Calibration, Black bodies, Shortwaves, Bolometers, Lamps, Space operations, Sensor calibration, Tungsten, Aluminum

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The Clouds and Earth's Radiant Energy System (CERES thermistor bolometers were calibrated using filtered radiances, characterized on an International Temperature Scale of 1990 (ITS-90) derived absolute radiometric scale. Longwave filtered radiances were characterized using the optical and geometric surface properties of the reference Narrow-Field-of-View Blackbody (NFBB), the NFBB temperature measurements from the ITS-90 calibrated platinum resistance thermometers (PRT) embedded in the blackbodies, and the spectral responses of the CERES bolometers. Shortwave filtered radiances were characterized using the cryogenically-cooled Transfer Active Cavity Radiometer (TACR) which was an ITS-90 transfer standard, and using the spectral responses of the bolometers. In ground vacuum facilities, the ITS-90, temperature-based radiometric scale was transferred to the CERES bolometers. As ITS-90 transfer standards, the bolometers were used to characterize the emitted filtered radiances from in-flight systems: (1) the internal calibration module (ICM) which consisted of anodized aluminum blackbodies and tungsten lamp sources; and (2) mirror attenuator mosaic (MAM) which was an aluminum solar diffuser plate, built into the bolometer instrumentation. From the ground [October 1995] through the on-orbit phases [December 1998 - July 1999] of the Tropical Rainfall Measuring Mission (TRMM) Spacecraft CERES instrument mission, the stabilities of the bolometer's responses were assessed from periodical observations of the in-flight calibration systems radiances. Each CERES instrument package consisted of broadband shortwave [0.3 micrometer to 5.0 micrometer], broadband total [0.3 micrometer to greater than 100 micrometer], and narrowband window [8 micrometer and 12 micrometer], scanning thermistor bolometer sensor units; and of in-flight calibration systems. Between the ground and initial on-orbit calibrations, the TRMM CERES bolometers and the built-in, flight calibration system sources maintained their filtered radiance measurement ties to ITS-90 at the plus or minus 0.2 Wm^-2sr^-1 precision level. On-orbit calibration studies indicate that the radiance measurements were stable at the plus or minus 0.2 Wm^-2sr^-1 precision level. The ground and on- orbit calibration results are presented and discussed.

Proceedings Article | 24 September 1999 Paper

Analyses of on-orbit determinations of the Clouds and the Earth's Radiant Energy System (CERES) thermistor bolometer sensor zero-radiance offsets

Robert Lee, Susan Thomas, Kory Priestley, Bruce Barkstrom, Jack Paden, Dhirendra Pandey, G. Louis Smith, Aiman Al-Hajjah, Robert Wilson

Proceedings Volume 3750, (1999) https://doi.org/10.1117/12.363545

KEYWORDS: Sensors, Space operations, Content addressable memory, Shortwaves, Bolometers, Clouds, Solar energy, Black bodies, Calibration, Instrument modeling

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