Mr. Phillip C. Hess Profile

Phillip C. Hess

at Science Systems and Applications Inc

SPIE Involvement:

Author

Publications (19)

Proceedings Article | 9 September 2019 Presentation + Paper

Performance trends of Clouds and the Earth’s Radiant Energy System (CERES) instruments aboard terra, aqua, S-NPP and NOAA-20 missions

Susan Thomas, K. Priestley, M. Shankar, P. Hess, R. Wilson, N. Smith, D. Walikainen, Z. Szewczyk

Proceedings Volume 11127, 1112716 (2019) https://doi.org/10.1117/12.2530828

KEYWORDS: Sensors, Shortwaves, Calibration, Space operations, Clouds, Sensor calibration, Instrument modeling, Sensor performance, Black bodies, Lamps

Read Abstract +

Clouds and the Earth’s Radiant Energy System (CERES) instrument was designed to provide accurate measurements for the long-term monitoring of Earth’s radiation energy budget. Seven copies of the CERES instruments were built by Northrop Grumman Aerospace Systems (NGAS) and has been flying aboard five spacecraft platforms. The CERES instrument with the three scanning sensors measure radiances in 0.3 to 5.0 micron region with Shortwave sensor, 0.3 to >100 microns with Total sensor, and either a 8 - 12 micron region Window sensor on the first six instruments or a 5 – 35 micron longwave sensor on the seventh Flight Model 6 (FM6) instrument. Currently there are six instruments actively collecting Longwave and Shortwave measurements. Four of the CERES instruments (Flight Models1 through 4) fly aboard Earth Observing System (EOS) Terra and Aqua platforms with two instruments aboard each spacecraft. Flight Models 5 and 6 are aboard the Suomi-NPP and NOAA-20 spacecrafts. The pre-launch accuracy goal for the CERES instrument measurements is to have the emitted longwave radiances within 0.5% and the shortwave radiances within 1.0%. The in-flight evaluation of the sensor performance are carried out using the internal calibration module (ICM) comprising of blackbody sources and tungsten lamp, and a solar diffuser plate known as the Mirror Attenuator Mosaic (MAM). The ICM and MAM calibration results are instrumental in understanding the ground to flight shift and in-flight drifts in CERES sensors’ gains. In addition, several validation studies utilising targets such as tropical ocean and deep convective clouds are performed as part of the Cal/Val protocol. Comparisons of sensor measurements from instruments on the same spacecraft as well as coincident measurements of CERES instruments on different spacecraft at overpass regions are also performed to support the intercomparison studies between the sensors of different instruments. The calibration and validation studies collectively provide good understanding of the instrument performance and any changes occuring at different spectral regions of the sensors. This paper discusses the various studies utilized to evaluate the sensor perform.

Proceedings Article | 5 September 2017 Paper

A strategy to assess the pointing accuracy of the CERES FM1-FM5 scanners

Nathaniel Smith, Z. Peter Szewczyk, Phillip Hess, Kory Priestley

Proceedings Volume 10402, 104020R (2017) https://doi.org/10.1117/12.2271644

KEYWORDS: Space operations, Solar radiation, Scanners, Clouds, Solar energy, Radiometry, Sensors, Temperature metrology, Detection and tracking algorithms, Sensor calibration

Read Abstract +

Proceedings Article | 8 September 2015 Paper

Assessment of the clouds and the Earth’s Radiant Energy System (CERES) instrument performance and stability on the Aqua, Terra, and S-NPP spacecraft

Nathaniel Smith, Susan Thomas, Mohan Shankar, Phillip Hess, Natividad Smith, Dale Walikainen, Robert Wilson, Kory Priestley

Proceedings Volume 9607, 96070T (2015) https://doi.org/10.1117/12.2190110

KEYWORDS: Calibration, Sensors, Shortwaves, Space operations, Solar radiation, Satellites, Clouds, Solar energy, Black bodies, Radiometry

Read Abstract +

Proceedings Article | 26 September 2014 Paper

Assessment of the clouds and the Earth's radiant energy system (CERES) flight model 5 (FM5) instrument's performance and stability

Nathaniel Smith, Susan Thomas, Mohan Shankar, Z. Szewczyk, Robert Wilson, Dale Walikainen, Janet Daniels, Phillip Hess, Kory Priestley

Proceedings Volume 9218, 921802 (2014) https://doi.org/10.1117/12.2061833

KEYWORDS: Calibration, Sensors, Shortwaves, Black bodies, Satellites, Solar radiation, Space operations, Solar radiation models, Clouds, Instrument modeling

Read Abstract +

Proceedings Article | 23 September 2013 Paper

Early trends on the CERES FM5 instrument performance using in-flight calibration sources

Nathaniel Smith, Susan Thomas, Mark Timcoe, Phillip Hess, Kory Priestley

Proceedings Volume 8866, 886608 (2013) https://doi.org/10.1117/12.2024279

KEYWORDS: Calibration, Sensors, Shortwaves, Black bodies, Space operations, Solar radiation, Aerospace engineering, Solar radiation models, Photodiodes, Satellites

Read Abstract +

Proceedings Article | 23 September 2013 Paper

Performance assessment of the Clouds and the Earth's Radiant Energy System (CERES) instruments aboard Terra and Aqua spacecraft

Susan Thomas, K. Priestley, M. Shankar, N. Smith, N. Loeb, D. Walikainen, P. Hess, R. Wilson

Proceedings Volume 8866, 886606 (2013) https://doi.org/10.1117/12.2024963

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

Read Abstract +

Clouds and the Earth's Radiant Energy System (CERES) instruments were designed to measure the reflected shortwave and emitted longwave radiances of the Earth’s radiation budget and to investigate the cloud interactions with global radiances for the long-term monitoring of Earth's climate. The three scanning thermistor bolometer sensors on CERES 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. Of the five CERES instruments that are currently in operation, four of the CERES instruments (Flight Models1 through 4) fly aboard Earth Observing System (EOS) Terra and Aqua platforms with two instruments aboard each spacecraft, in 705 KM sun-synchronous orbits of 10:30 AM and 1:30 PM equatorial crossing time.

A rigorous and comprehensive radiometric calibration and validation protocol comprising of various studies was developed to evaluate the calibration accuracy of the CERES instruments. The in-flight calibration of CERES sensors are carried out using the internal calibration module (ICM) comprising of blackbody sources and quartzhalogen tungsten lamp, and a solar diffuser plate known as the Mirror Attenuator Mosaic (MAM). The ICM calibration results are instrumental in determining the changes in CERES sensors’ gains after launch from the prelaunch determined values and the on-orbit gain variations. In addition to the broadband response changes derived from the on-board blackbody and the tungsten lamp, the shortwave and the total sensors show a spectrally dependent drop in responsivity in the shorter wavelegth region below one micron that were brought to light through validation studies. The spectrally dependent changes were attributed to the instrument operational modes and the corrections were derived using the sensor radiance comparisons. This paper covers the on-orbit behavior of CERES sensors aboard the Terra and Aqua spacecraft and the determination of the sensor response changes utilising the in-flight calibration and the radiance measurement comparisons viewing various targets. The corrections for the sensor response changes were incorporated in the radiance calculations of CERES Edition3 data products.

Proceedings Article | 23 September 2013 Paper

On-orbit solar calibration methods using the Clouds and Earth's Radiant Energy System (CERES) in-flight calibration system: lessons learned

Robert Wilson, Kory Priestley, Susan Thomas, Phillip Hess, Mohan Shankar, Nathaniel Smith, Peter Szewczyk

Proceedings Volume 8866, 886607 (2013) https://doi.org/10.1117/12.2025967

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

Read Abstract +

The Clouds and Earth's Radiant Energy System (CERES) scanning thermistor bolometers measure earth-reflected solar and earth-emitted long-wave radiances, at the top- of-the-atmosphere. The bolometers measure the earth radiances in the broadband shortwave solar (0.3-5.0 microns) and total (0.3->100 microns) spectral bands as well as in the 8->12 microns water vapor window spectral band over geographical footprints as small as 10 kilometers at nadir. December 1999, the second and third set of CERES bolometers was launched on the Earth Observing Mission Terra Spacecraft. May 2003, the fourth and fifth set of bolometers was launched on the Earth Observing Mission Aqua Spacecraft. Recently, (October 2011) the sixth instrument was launched on the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (Suomi NPP) Spacecraft. Ground vacuum calibrations define the initial count conversion coefficients that are used to convert the bolometer output voltages into filtered earth radiances. The mirror attenuator mosaic (MAM), a solar diffuser plate, was built into the CERES instrument package calibration system in order to define on-orbit shifts or drifts in the sensor responses. It followed a similar design as the Earth Radiation Budget Experiment (ERBE) scanners with improvements from lessons learned.

The shortwave and shortwave part of the total-wave sensors are calibrated using the solar radiances reflected from the MAM's. Each MAM consists of baffle-solar diffuser plate systems, which guide incoming solar radiances into the instrument fields of view of the shortwave and total wave sensor units. The MAM diffuser reflecting type surface consists of an array of spherical aluminum mirror segments, which are separated by a Merck Black A absorbing surface, over-coated with SIOx (SIO2 for PFM). Thermistors are located within each MAM plate and the total channel baffle. The CERES MAM is designed to yield calibration precisions approaching .5 percent for the total and shortwave detectors. The Terra FM1 and FM2 shortwave channels and the FM1 and FM2 total channels MAM calibration systems showed shifts in their solar calibrations of 1.5, 2.5, 1.5 and 6 percent, respectively within the first year. The Aqua FM3, and FM4 shortwave channels and the FM3 and FM4 total channels MAM calibration systems showed shifts in their solar calibrations of 1.0, 1.2, 2.1 and .8 percent, respectively within the first year. A possible explanation has attributed the MAM reflectance change to on-orbit solar ultraviolet/atomic oxygen/out-gassing induced chemical changes to the SIOx coated MAM assembly during ram and solar exposure. There is also changes to the sensor telescope shortwave filters as well as the Total channel mirrors and/or sensors. The Soumi NPP FM5 is still after 2.5 years displaying a stability of less than .5 percent. In this presentation, lessons learned from the ERBE MAM and application of knowledge of how the space environment affected the CERES FM1-4 solar calibrations will be presented along with on-orbit measurements for the thirteen years the CERES instruments have been on-orbit.

Proceedings Article | 19 October 2012 Paper

Performance of the Clouds and the Earth's Radiant Energy System (CERES) Flight Model 5 (FM5) instrument on NPP mission

Susan Thomas, Kory Priestley, Phillip Hess, Robert Wilson, Nathaniel Smith, Mark Timcoe, Mohan Shankar, Dale Walikainen

Proceedings Volume 8510, 851005 (2012) https://doi.org/10.1117/12.930775

KEYWORDS: Sensors, Calibration, Shortwaves, Space operations, Clouds, Instrument modeling, Systems modeling, Lamps, Aerospace engineering, Diffusers

Read Abstract +

Proceedings Article | 19 October 2012 Paper

A strategy to assess the pointing accuracy of the CERES (FM5) scanner

Nathaniel Smith, Z. Szewczyk, Phillip Hess, Kory Priestley

Proceedings Volume 8510, 851006 (2012) https://doi.org/10.1117/12.929952

KEYWORDS: Space operations, Clouds, Solar radiation, Point spread functions, Scanners, Satellites, Radiometry, Detection and tracking algorithms, Solar energy, Shortwaves

Read Abstract +

Proceedings Article | 15 October 2012 Paper

Performance stability of the Clouds and Earth's Radiant Energy System (CERES) instrument sensors on board the Aqua and Terra spacecraft

Mohan Shankar, Kory Priestley, Susan Thomas, Phillip Hess, Dale Walikainen

Proceedings Volume 8510, 851004 (2012) https://doi.org/10.1117/12.930027

KEYWORDS: Sensors, Shortwaves, Calibration, Space operations, Black bodies, Clouds, Mirrors, Head, Lamps, Diffusers

Read Abstract +

Proceedings Article | 15 October 2012 Paper

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

Robert Wilson, Kory Priestley, Susan Thomas, Phillip Hess

Proceedings Volume 8510, 851003 (2012) https://doi.org/10.1117/12.930922

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

Read Abstract +

The Clouds and Earth's Radiant Energy System (CERES) scanning thermistor bolometers measure earth-reflected solar and earth-emitted longwaveradiances, at the top- of-the-atmosphere. The bolometers measure the earthradiances in the broadband shortwave solar (0.3-5.0 microns) and total (0.3-<100 microns) spectral bands as well as in the 8-<12 microns water vapor window spectral band over geographical footprints as small as 10 kilometers at nadir. December 1999, the second and third set of CERES bolometers was launchedon the Earth Observing Mission Terra Spacecraft. May 2003, the fourth and fifth set of bolometers was launched on the Earth Observing Mission Aqua Spacecraft. Recently, (October 2011) the sixth instrument was launched on the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (Suomi NPP) Spacecraft. Ground vacuum calibrations define the initial count conversion coefficients that are used to convert the bolometer output voltages into filtered earth radiances. The mirror attenuator mosaic (MAM), a solar diffuser plate, was built into the CERES instrument package calibration system in order to define in-orbit shifts or drifts in the sensor responses. The shortwave and shortwave part of the total sensors are calibrated using the solar radiances reflected from the MAM's. Each MAM consists of baffle-solar diffuser plate systems, which guide incoming solar radiances into the instrument fields of view of the shortwave and total wave sensor units. The MAM diffuser reflecting type surface consists of an array of spherical aluminum mirror segments, which are separated by a Merck Black A absorbing surface, overcoated with SIOx (SIO2 for PFM). Thermistors are located in each MAM plate and the total channel baffle. The CERES MAM is designed to yield calibration precisions approaching .5 percent for the total and shortwave detectors. In this presentation, the MAM solar calibration contrasting procedures will be presented along with on-orbit measurements for the eleven years the CERES instruments have been on-orbit. A switch to an azimuth rotation raster scan of the Sun rather than a fixed azimuth rotating elevation scan will be discussed. Comparisons are also made between the Terra, Aqua, and Suomi NPP CERES instruments during their MAM solar calibrations and total solar irradiance experimental results to determine how precise the CERES solar calibration facilities are at tracking the sun's irradiance.

Proceedings Article | 11 November 2010 Paper

Characterization of the clouds and the Earth's radiant energy system (CERES) sensors on Terra and Aqua spacecraft

Susan Thomas, K. Priestley, N. Smith, N. Loeb, P. Hess, M. Shankar, D, Walikainen, Z. Szewczyk, R. Wilson, D. Cooper

Proceedings Volume 7862, 78620N (2010) https://doi.org/10.1117/12.869684

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

Read Abstract +

Proceedings Article | 28 August 2010 Paper

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

Robert Wilson, Kory Priestley, Susan Thomas, Phillip Hess

Proceedings Volume 7807, 78070D (2010) https://doi.org/10.1117/12.862172

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

Read Abstract +

The Clouds and Earth's Radiant Energy System (CERES) scanning thermistor bolometers measure earth-reflected solar and earth-emitted longwaveradiances, at the top- of-the-atmosphere. The bolometers measure the earthradiances in the broadband shortwave solar (0.3-5.0 microns) and total (0.3->100 microns) spectral bands as well as in the 8->12 microns water vapor window spectral band over geographical footprints as small as 10 kilometers at nadir. December 1999, the second and third set of CERES bolometers was launchedon the Earth Observing Mission Terra Spacecraft. May 2003, the fourth and fifth set of bolometers was launched on the Earth Observing Mission Aqua Spacecraft. Ground vacuum calibrations define the initial count conversion coefficients that are used to convert the bolometer output voltages into filtered earth radiances. The mirror attenuator mosaic (MAM), a solar diffuser plate, was built into the CERES instrument package calibration system in order to define in-orbit shifts or drifts in the sensor responses. The shortwave and shortwave part of total sensors are calibrated using the solar radiances reflected from the MAM's. Each MAM consists of baffle-solar diffuser plate systems, which guide incoming solar radiances into the instrument fields of view of the shortwave and total wave sensor units. The MAM diffuser reflecting type surface consists of an array of spherical aluminum mirror segments, which are separated by a Merck Black A absorbing surface, overcoated with SIOx. Thermistors are located in each MAM plate and the total channel baffle. The CERES MAM is designed to yield calibration precisions approaching .5 percent for the total and shortwave detectors. However, in their first year of operation the Terra and Aqua MAMs showed shifts in their calibrations larger than expected. Shifts of this nature have been seen in other Solar viewing instruments in the past. A possible explanation has attributed the changes to pre-orbit or on-orbit contamination combined with solar ultraviolet/atomic oxygen induced chemical changes to the contaminant during solar exposure. In the subsequent year of operation all instruments begin to stabilize within the .5 percent precision range. In this presentation, the MAM solar calibration procedures will be presented along with on-orbit measurements for the nine years the CERES instruments have been on-orbit. A switch to an azimuth rotation raster scan of the Sun rather than an elevation scan will be discussed. The implementation of a thermal correction to the shortwave channel will also be discussed. Comparisons are also made between the Terra CERES instruments and the Aqua instruments during their MAM solar calibrations and total solar irradiance experimental results to determine how precise the CERES solar calibration facilities are at tracking the sun's irradiance.

Proceedings Article | 28 August 2009 Paper

Sensor performance of Clouds and the Earth's Radiant Energy System (CERES) instruments aboard EOS Terra and Aqua spacecraft based on post-launch calibration studies

Susan Thomas, K. Priestley, P. Hess, R. Wilson, M. Avery, D. Walikainen, Z. P. Szewczyk, D. Cooper, M. Shankar

Proceedings Volume 7452, 74520I (2009) https://doi.org/10.1117/12.828487

KEYWORDS: Sensors, Shortwaves, Calibration, Space operations, Clouds, Black bodies, Lamps, Tungsten, Sensor calibration, Sensor performance

Read Abstract +

Proceedings Article | 26 August 2009 Paper

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

Robert Wilson, Kory Priestley, Susan Thomas, Phillip Hess

Proceedings Volume 7452, 74520J (2009) https://doi.org/10.1117/12.827305

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

Read Abstract +

Proceedings Article | 5 October 2007 Paper

Radiometric performance of the CERES Earth radiation budget climate record sensors on the EOS Aqua and Terra spacecraft

Kory Priestley, G. Louis Smith, Susan Thomas, Denise Cooper, Robert Lee, Dale Walikainen, Phil Hess, Z. Peter Szewczyk, Robert Wilson

Proceedings Volume 6677, 66770H (2007) https://doi.org/10.1117/12.735294

KEYWORDS: Calibration, Shortwaves, Space operations, Climatology, Sensors, Black bodies, Optical filters, Environmental sensing, Earth's atmosphere, Radiometry

Read Abstract +

Proceedings Article | 8 December 2006 Paper

Radiometric stability results of clouds and the Earth's radiant energy system (CERES) instrument sensors aboard EOS Terra and Aqua spacecraft

Susan Thomas, K. Priestley, R. Wilson, G. Matthews, D. Walikainen, D. Cooper, P. Hess

Proceedings Volume 6408, 640805 (2006) https://doi.org/10.1117/12.694077

KEYWORDS: Sensors, Shortwaves, Calibration, Space operations, Clouds, Sensor calibration, Black bodies, Diffusers, Lamps, Mirrors

Read Abstract +

Proceedings Article | 10 November 2003 Paper

Geolocation validation of CERES instruments using radiance measurements

Peter Spence, Phillip Hess, Kory Priestley

Proceedings Volume 5151, (2003) https://doi.org/10.1117/12.506073

KEYWORDS: Error analysis, Satellites, Sensors, Clouds, Detection and tracking algorithms, Bolometers, Shortwaves, Space operations, Solar radiation, Logic

Read Abstract +

Proceedings Article | 24 September 1999 Paper

Selected CERES electronic component survivability under simulated overvoltage conditions

John Chapman, Michael Grant, James Bockman, Vernon Clark, Phillip Hess

Proceedings Volume 3750, (1999) https://doi.org/10.1117/12.363546

KEYWORDS: Voltage controlled current source, Space operations, Modulation transfer functions, Calibration, Electronic components, Manufacturing, Electronic circuits, Analog electronics, Silicon, Amplifiers

Read Abstract +

Showing 5 of 19 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years