Dr. Hongda Chen Profile

Dr. Hongda Chen

Sr. Research Scientist at NASA-SSAI

SPIE Involvement:

Author

Publications (53)

Proceedings Article | 20 November 2024 Presentation + Paper

An update of NOAA-21 VIIRS on-orbit calibration and performance

Xiaoxiong Xiong, Amit Angal, Ning Lei, Kevin Twedt, Hongda Chen, Kwofu Chiang

Proceedings Volume 13192, 131920X (2024) https://doi.org/10.1117/12.3029870

KEYWORDS: Calibration, Sensors, Stray light, Space operations, Short wave infrared radiation, Signal to noise ratio, Diffusers, Satellites

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Proceedings Article | 13 November 2024 Presentation + Paper

On-orbit calibration and performance of the NOAA-21 VIIRS day-night band

H. Chen, D. Link, G. Sarid, K. Chiang, X. Xiong

Proceedings Volume 13197, 131970O (2024) https://doi.org/10.1117/12.3030769

KEYWORDS: Calibration, Sensors, Space operations

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Proceedings Article | 19 October 2023 Poster + Paper

NOAA-21 VIIRS day-night band on-orbit calibration and performance in early mission

H. Chen, J. Sun, D. Link, C. Sun, K. Chiang, X. Xiong

Proceedings Volume 12729, 127291G (2023) https://doi.org/10.1117/12.2678663

KEYWORDS: Calibration, Contamination, Magnesium, Equipment, Space operations, Sun, Signal detection, Satellites, Displays, Diffusers

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Proceedings Article | 19 October 2023 Presentation + Paper

An overview of NOAA-21 VIIRS early on-orbit calibration and performance

Xiaoxiong Xiong, Amit Angal, Junqiang Sun, Ning Lei, Kevin Twedt, Hongda Chen, Kwofu Chiang

Proceedings Volume 12729, 1272916 (2023) https://doi.org/10.1117/12.2680636

KEYWORDS: Calibration, Equipment, Stray light, Signal to noise ratio, Displays, Data transmission, Space operations, Short wave infrared radiation, Sensors, Satellites

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Proceedings Article | 3 October 2022 Presentation

Uncertainty analysis for SNPP and NOAA-20 VIIRS day-night band

Junqiang Sun, Hongda Chen, Gal Sarid, Chengbo Sun, Daniel Link, Xiaoxiong Xiong

Proceedings Volume 12232, 122320O (2022) https://doi.org/10.1117/12.2632306

KEYWORDS: Uncertainty analysis, Sensors, Calibration, Reflectivity, Mirrors, Magnesium, Diffusers, Americium

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Proceedings Article | 30 September 2022 Presentation + Paper

S-NPP and NOAA-20 VIIRS day-night band on-orbit calibration and performance

H. Chen, C. Sun, D. Link, G. Sarid, J. Sun, X. Xiong

Proceedings Volume 12232, 122320P (2022) https://doi.org/10.1117/12.2632310

KEYWORDS: Sensors, Calibration, Contamination, Signal to noise ratio, Satellites, Diffusers

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Proceedings Article | 12 September 2021 Presentation + Paper

MODIS reflective solar bands calibration improvements for Collection 7

Kevin Twedt, Emily Aldoretta, Amit Angal, Hongda Chen, Xu Geng, Yonghong Li, Qiaozhen Mu, Kevin Vermeesch, Xiaoxiong Xiong

Proceedings Volume 11858, 118580S (2021) https://doi.org/10.1117/12.2597551

KEYWORDS: Calibration, Reflectivity, MODIS, Sensors, Short wave infrared radiation, Mirrors, Polarization, Image quality, Remote sensing

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Proceedings Article | 1 August 2021 Presentation + Paper

MODIS reflective solar band calibration improvements using pseudo-invariant desert targets

H. Chen, K. Twedt, K. Vermeesch, E. Aldoretta, A. Angal, X. Xiong

Proceedings Volume 11829, 118290Z (2021) https://doi.org/10.1117/12.2593364

KEYWORDS: Calibration, MODIS, Reflectivity, Sensors, Polarization, Satellites, Data processing, Bidirectional reflectance transmission function

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To provide the best science data quality, an accurate characterization of the response versus scan angle (RVS) function is critical for the MODIS reflective solar bands (RSB) on-orbit calibration. In every MODIS operational scan, the Earth’s surface, referred to here as Earth view (EV), the space view (SV) port, and the onboard calibrators are viewed via a twosided scan mirror. The RVS is defined as the sensor’s relative response as a function the angle of incidence (AOI) to the scan mirror. Many different approaches have been developed to derive the time-dependent RVS and its look-up table (LUT) applied to MODIS Level 1B (L1B) products since calibration Collection 4. For most MODIS RSB, the on-board calibrators can reasonably track the RVS change with time. In practice, their RVS is derived using data from on-board calibrators and the EV mirror side ratio (for mirror side 2). For Terra bands 1-4, 8-10 and Aqua bands 1-4, 8-9, an enhancement has been employed in Collections 6 and 6.1 (C6/C6.1) by using Earth scene response trending from pseudoinvariant desert sites in addition to the onboard calibrators. The current C6/C6/1 RVS algorithm is focused on fitting the EV data at each AOI over time and then deriving the relative change at different AOI. The EV response trending is currently fitted with multiple segments over time. Alternatively, the EV responses can be fit first as a function of AOI before fitting temporally in order to reduce the dependence on the stability of the desert site. These pre-treatment methods on the EV data provide improvement in the derived calibration coefficients. However, evidence of insufficient calibration is still observed in the MODIS L1B reflectance data, especially in the form of differences between the mirror sides. In this paper, we review the current methodologies that utilize the EV response trends from the pseudo-invariant Libyan desert targets to supplement the gain derived from the onboard calibrators. An improvement is then proposed and investigated such that a sliding window average (SWA) is used to pre-process the raw EV data. The SWA parameters are carefully selected using trade-off studies to accurately track the Earth scene response trending in multiple cases to overcome the reflectance differences between two mirror sides. Calibration results show improvements for both Aqua and Terra MODIS RSB L1B data products. This new adjustment has been included in the recently delivered Collection 7 LUT that will be evident in the L1B products expected to be released in late 2021.

SPIE Journal Paper | 1 September 2020

NOAA-20 Visible Infrared Imaging Radiometer Suite day–night band on-orbit calibration and performance

Hongda Chen, Xiaoxiong Xiong, Daniel Link, Chengbo Sun, Kwofu Chiang

JARS, Vol. 14, Issue 03, 034516, (September 2020) https://doi.org/10.1117/12.10.1117/1.JRS.14.034516

KEYWORDS: Calibration, Sensors, Visible radiation, Radiometry, Infrared imaging, Magnesium, Signal to noise ratio, Contamination, Space operations, Sun

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Proceedings Article | 20 August 2020 Poster + Paper

The MODIS RSB calibration and look-up table delivery process for collections 6 and 6.1

Emily Aldoretta, Amit Angal, Kevin Twedt, Hongda Chen, Yonghong Li, Daniel Link, Qiaozhen Mu, Kevin Vermeesch, Xiaoxiong Xiong

Proceedings Volume 11501, 115011Q (2020) https://doi.org/10.1117/12.2570785

KEYWORDS: MODIS, Calibration, Sensors, Reflectivity, Mirrors

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Proceedings Article | 20 August 2020 Presentation + Paper

New VIIRS DNB stray light correction method

Qiang Ji, Hongda Chen, Thomas Schwarting, Chengbo Sun, Xiaoxiong Xiong

Proceedings Volume 11501, 1150111 (2020) https://doi.org/10.1117/12.2567736

KEYWORDS: Stray light, Satellites, Satellite imaging, Sensors, Image processing

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Proceedings Article | 9 September 2019 Presentation + Paper

NOAA-20 VIIRS DNB straylight analysis and calibration before/after cryo-cooler door opening

H. Chen, H. Oudrari, C. Sun, K. Chiang, X. Xiong

Proceedings Volume 11127, 111271V (2019) https://doi.org/10.1117/12.2528742

KEYWORDS: Contamination, Calibration, Sensors, Algorithm development, Space operations, Staring arrays, Airglow, Stray light analysis, Image quality, Charge-coupled devices

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Proceedings Article | 9 September 2019 Paper

Lunar calibration and performance assessments of the NOAA-20 VIIRS reflective solar bands

Amit Angal, Xiaoxiong Xiong, Truman Wilson, Xu Geng, Hongda Chen

Proceedings Volume 11127, 111272B (2019) https://doi.org/10.1117/12.2530024

KEYWORDS: Calibration, Sensors, MODIS, Reflectivity, Space operations, Algorithm development, Staring arrays, Long wavelength infrared, Robotics, Observatories

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Proceedings Article | 9 September 2019 Presentation + Paper

VIIRS DNB time-dependent stray light correction

Chengbo Sun, Thomas Schwarting, Xu Geng, Kwofu Chiang, Hongda Chen, Xiaoxiong Xiong

Proceedings Volume 11127, 111271W (2019) https://doi.org/10.1117/12.2528881

KEYWORDS: Stray light, Contamination, Satellites, Data processing, Algorithm development

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Proceedings Article | 9 September 2019 Paper

Comparison of MODIS solar diffuser stability monitor calibration results for different operational configurations

Kevin Twedt, Amit Angal, Hongda Chen, Xiaoxiong Xiong

Proceedings Volume 11127, 1112728 (2019) https://doi.org/10.1117/12.2528444

KEYWORDS: Calibration, MODIS, Sensors, Sun, Reflectivity, Diffusers, Transmittance

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Proceedings Article | 9 September 2019 Presentation + Paper

Reprocessing of S-NPP VIIRS DNB detector gains and dark offsets

Chengbo Sun, Thomas Schwarting, Kwofu Chiang, Hongda Chen, Sergey Gusev, Xiaoxiong Xiong

Proceedings Volume 11127, 111271U (2019) https://doi.org/10.1117/12.2528891

KEYWORDS: Sensors, Calibration, Detection and tracking algorithms

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SPIE Journal Paper | 29 May 2019

Stray-light correction and prediction for Suomi National Polar-orbiting Partnership visible infrared imaging radiometer suite day-night band

Hongda Chen, Xiaoxiong Xiong, Xu Geng, Kevin Twedt

JARS, Vol. 13, Issue 02, 024521, (May 2019) https://doi.org/10.1117/12.10.1117/1.JRS.13.024521

KEYWORDS: Stray light, Contamination, Sensors, Visible radiation, Infrared imaging, Radiometry, Space operations, Data fusion, Calibration, Airglow

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Proceedings Article | 11 October 2018 Paper

Performance assessments and comparisons of S-NPP and NOAA-20 (JPSS-1) VIIRS on-orbit calibration

Xiaoxiong Xiong, Amit Angal, James Butler, Hongda Chen, Kwofu Chiang, Ning Lei, Yonghong Li, Kevin Twedt

Proceedings Volume 10785, 1078514 (2018) https://doi.org/10.1117/12.2326866

KEYWORDS: Calibration, Sensors, Signal to noise ratio, Long wavelength infrared, Black bodies, Stray light, Contamination, Bidirectional reflectance transmission function, Near infrared, Satellites

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Proceedings Article | 9 October 2018 Presentation + Paper

Preliminary study of JPSS-1/NOAA-20 VIIRS day-night band straylight characterization and correction methods

H. Chen, H. Oudrari, C. Sun, T. Schwarting, X. Xiong

Proceedings Volume 10789, 1078907 (2018) https://doi.org/10.1117/12.2325458

KEYWORDS: Contamination, Sensors, Calibration, Image quality

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Proceedings Article | 25 September 2018 Presentation + Paper

An early assessment of JPSS-1/NOAA-20 VIIRS day-night band on-orbit calibration and performance

H. Chen, H. Oudrari, C. Sun, T. Schwarting, X. Xiong

Proceedings Volume 10785, 1078517 (2018) https://doi.org/10.1117/12.2325451

KEYWORDS: Calibration, Sensors, Signal to noise ratio, MODIS

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Proceedings Article | 7 September 2018 Paper

On-orbit performance of the Terra and Aqua MODIS solar diffuser stability monitor

Emily Aldoretta, Kevin Twedt, Amit Angal, Hongda Chen, Xiaoxiong Xiong

Proceedings Volume 10764, 107641O (2018) https://doi.org/10.1117/12.2321163

KEYWORDS: Signal to noise ratio, Calibration, MODIS, Sensors, Diffusers, Reflectivity, Signal detection, Interference (communication), Space operations, Sun

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Proceedings Article | 7 September 2018 Paper

Methods of Earth-view-based calibration of the response versus scan angle of the MODIS reflective solar bands

Kevin Twedt, Hongda Chen, Xiaoxiong Xiong, Amit Angal, Xu Geng, Aisheng Wu

Proceedings Volume 10764, 107641P (2018) https://doi.org/10.1117/12.2321231

KEYWORDS: Calibration, MODIS, Reflectivity, Bidirectional reflectance transmission function, Sensors, Algorithm development

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SPIE Journal Paper | 16 July 2018 Open Access

Updates of Moderate Resolution Imaging Spectroradiometer on-orbit calibration uncertainty assessments

Xiaoxiong Xiong, Amit Angal, William L. Barnes, Hongda Chen, Vincent Chiang, Xu Geng, Yonghong Li, Kevin Twedt, Zhipeng Wang, Truman Wilson, Aisheng Wu

JARS, Vol. 12, Issue 03, 034001, (July 2018) https://doi.org/10.1117/12.10.1117/1.JRS.12.034001

KEYWORDS: Calibration, MODIS, Sensors, Spectral calibration, Reflectivity, Mirrors, Short wave infrared radiation, Detection and tracking algorithms, Polarization, Imaging systems

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Proceedings Article | 5 September 2017 Presentation + Paper

Prediction of S-NPP VIIRS DNB gains and dark offsets

Chengbo Sun, Thomas Schwarting, Hongda Chen, Kwofu Chiang, Xiaoxiong Xiong

Proceedings Volume 10402, 104021U (2017) https://doi.org/10.1117/12.2274118

KEYWORDS: Calibration, Data modeling, Sensors, Remote sensing, Data processing

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Proceedings Article | 5 September 2017 Paper

MODIS solar diffuser degradation at short-wave infrared band wavelengths

Kevin Twedt, Amit Angal, Xiaoxiong Xiong, Xu Geng, Hongda Chen

Proceedings Volume 10402, 104022K (2017) https://doi.org/10.1117/12.2274272

KEYWORDS: MODIS, Short wave infrared radiation, Calibration, Reflectivity, Diffusers

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Proceedings Article | 5 September 2017 Paper

Prediction of S-NPP VIIRS DNB stray light correction

Chengbo Sun, Thomas Schwarting, Hongda Chen, Kwofu Chiang, Xiaoxiong Xiong

Proceedings Volume 10402, 104022J (2017) https://doi.org/10.1117/12.2274136

KEYWORDS: Stray light, Data processing, Contamination, Low light imagers, Air contamination, Light sources, Algorithm development, Calibration, Remote sensing

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Proceedings Article | 5 September 2017 Paper

Updates of MODIS on-orbit calibration uncertainty assessments

Xiaoxiong Xiong, Amit Angal, William Barnes, Hongda Chen, Vincent Chiang, Xu Geng, Yonghong Li, Kevin Twedt, Zhipeng Wang, Truman Wilson, Aisheng Wu

Proceedings Volume 10402, 104020M (2017) https://doi.org/10.1117/12.2276305

KEYWORDS: Calibration, MODIS, Reflectivity, Earth's atmosphere, Atmospheric sciences, Sensors, Sensor calibration, Satellites

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SPIE Journal Paper | 28 August 2017

Suomi-NPP VIIRS day–night band on-orbit calibration and performance

Hongda Chen, Xiaoxiong Xiong, Chengbo Sun, Xuexia Chen, Kwofu Chiang

JARS, Vol. 11, Issue 03, 036019, (August 2017) https://doi.org/10.1117/12.10.1117/1.JRS.11.036019

KEYWORDS: Calibration, Sensors, Magnesium, Sun, Modulation, Contamination, Space operations, Bidirectional reflectance transmission function, Signal detection, Mirrors

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Proceedings Article | 14 December 2016 Presentation + Paper

MODIS solar diffuser on-orbit degradation characterization using improved SDSM screen modeling

H. Chen, X. Xiong, A. Angal, Z. Wang, A. Wu

Proceedings Volume 10000, 100000X (2016) https://doi.org/10.1117/12.2239950

KEYWORDS: Sensors, Diffusers, MODIS, Calibration, Sun, Algorithm development, Reflectivity, Signal detection, Signal attenuation, Detection and tracking algorithms

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SPIE Journal Paper | 9 June 2016

Alternative method of on-orbit response-versus-scan-angle characterization for MODIS reflective solar bands

Hongda Chen, Xiaoxiong Xiong, Amit Angal, Xu Geng, Aisheng Wu

JARS, Vol. 10, Issue 02, 024004, (June 2016) https://doi.org/10.1117/12.10.1117/1.JRS.10.024004

KEYWORDS: MODIS, Reflectivity, Calibration, Mirrors, Sensors, Algorithm development, Detection and tracking algorithms, Diffusers, Space operations, Spectral calibration

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The moderate resolution imaging spectroradiometer (MODIS) has 20 reflective solar bands (RSB), covering a spectral range from 0.41 to 2.2 μm, which are calibrated on-orbit using its onboard calibrators, which include a solar diffuser, a solar diffuser stability monitor, and a spectroradiometric calibration assembly. A space view (SV) port is used to provide a background reference and also facilitates near-monthly lunar observations through a spacecraft roll. In every scan, the Earth’s surface, SV, and onboard calibrators are viewed via a two-sided scan mirror, the reflectance of which depends on the angle of incidence (AOI) as well as the wavelength of the incident light. Response-versus-scan-angle (RVS) is defined as a dependence function of the scan mirror’s reflectance over AOI. An initial RVS for each RSB was measured prelaunch for both Terra and Aqua MODIS. Algorithms have been developed to track the on-orbit RVS variation using the measurements from the onboard calibrators, supplemented with the earth view (EV) trends from pseudoinvariant desert targets obtained at different AOI. Since the mission beginning, the MODIS characterization support team (MCST) has dedicated efforts in evaluating approaches of characterizing the on-orbit RVS. A majority of the approaches focused on fitting the data at each AOI over time and then deriving the relative change at different AOI. The current version of the on-orbit RVS algorithm, as implemented in the collection 6 (C6) level-1B (L1B), is also based on the above rationale. It utilizes the EV response trends from the pseudoinvariant Libyan desert targets to supplement the gain derived from the onboard calibrators. The primary limitation of this approach is the assumption of the temporal stability of these desert sites. Consequently, MCST developed an approach that derives the on-orbit RVS change using measurements from a single desert site, combined with the on-orbit lunar measurements. In addition, the EV and onboard responses are fit first as a function of AOI before fitting temporally in order to eliminate the dependence on the stability of the desert site. Comprehensive comparisons are performed with current C6 RVS results for both Terra and Aqua MODIS. Results demonstrate that this alternative method provides a supplemental means to monitor the on-orbit RVS for MODIS RSB.

Proceedings Article | 2 May 2016 Paper

On-orbit performance and calibration improvements for the reflective solar bands of Terra and Aqua MODIS

Amit Angal, Xiaoxiong (Jack) Xiong, Aisheng Wu, Hongda Chen, Xu Geng, Daniel Link, Yonghong Li, Andrew Wald, Jake Brinkmann

Proceedings Volume 9881, 98811F (2016) https://doi.org/10.1117/12.2223912

KEYWORDS: MODIS, Calibration, Reflectivity, Diffusers, Sensors, Mirrors, Short wave infrared radiation, Signal to noise ratio, Neodymium, Detection and tracking algorithms

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Moderate Resolution Imaging Spectroradiometer (MODIS) is the keystone instrument for NASA’s EOS Terra and Aqua missions, designed to extend and improve heritage sensor measurements and data records of the land, oceans and atmosphere. The reflective solar bands (RSB) of MODIS covering wavelengths from 0.41 μm to 2.2 μm, are calibrated on-orbit using a solar diffuser (SD), with its on-orbit bi-directional reflectance factor (BRF) changes tracked using a solar diffuser stability monitor (SDSM). MODIS is a scanning radiometer using a two-sided paddle-wheel mirror to collect earth view (EV) data over a range of ±55° off instrument nadir. In addition to the solar calibration provided by the SD and SDSM system, lunar observations at nearly constant phase angles are regularly scheduled to monitor the RSB calibration stability. For both Terra and Aqua MODIS, the SD and lunar observations are used together to track the on-orbit changes of RSB response versus scan angle (RVS) as the SD and SV port are viewed at different angles of incidence (AOI) on the scan mirror. The MODIS Level 1B (L1B) Collection 6 (C6) algorithm incorporated several enhancements over its predecessor Collection 5 (C5) algorithm. A notable improvement was the use of the earth-view (EV) response trends from pseudo-invariant desert targets to characterize the on-orbit RVS for select RSB (Terra bands 1-4, 8, 9 and Aqua bands 8, 9) and the time, AOI, and wavelength-dependent uncertainty. The MODIS Characterization Support Team (MCST) has been maintaining and enhancing the C6 algorithm since its first update in November, 2011 for Aqua MODIS, and February, 2012 for Terra MODIS. Several calibration improvements have been incorporated that include extending the EV-based RVS approach to other RSB, additional correction for SD degradation at SWIR wavelengths, and alternative approaches for on-orbit RVS characterization. In addition to the on-orbit performance of the MODIS RSB, this paper also discusses in detail the recent calibration improvements implemented in the MODIS L1B C6.

Proceedings Article | 2 May 2016 Paper

On-orbit calibration and performance of S-NPP VIIRS DNB

H. Chen, C. Sun, X. Chen, K. Chiang, X. Xiong

Proceedings Volume 9881, 98812B (2016) https://doi.org/10.1117/12.2225105

KEYWORDS: Calibration, Sensors, Stray light, Contamination, Magnesium, Modulation, Bidirectional reflectance transmission function, Space operations, Mirrors, Airglow

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Proceedings Article | 19 November 2014 Paper

On-orbit performance of the MODIS SWIR bands

Amit Angal, Aisheng Wu, Xiaoxiong Xiong, Xu Geng, Daniel Link, Hongda Chen

Proceedings Volume 9264, 92641Q (2014) https://doi.org/10.1117/12.2069308

KEYWORDS: MODIS, Short wave infrared radiation, Reflectivity, Calibration, Sensors, Diffusers, Mid-IR, Neodymium, Mirrors, Near infrared

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Proceedings Article | 2 October 2014 Paper

Status of Terra MODIS operation, calibration, and performance

Xiaoxiong Xiong, Brian Wenny, Aisheng Wu, Amit Angal, Xu Geng, Hongda Chen, Jennifer Dodd, Daniel Link, Sriharsha Madhavan, Na Chen, Yonghong Li, Sean Iacangelo, William Barnes, Vince Salomonson

Proceedings Volume 9218, 92180O (2014) https://doi.org/10.1117/12.2062645

KEYWORDS: MODIS, Calibration, Sensors, Long wavelength infrared, Space operations, Mirrors, Diffusers, Electronics, Signal to noise ratio, Near infrared

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Proceedings Article | 26 September 2014 Paper

Using the moon to evaluate the radiometric calibration performance of S-NPP VIIRS thermal emissive bands

Zhipeng Wang, Xiaoxiong Xiong, Boryana Efremova, Hongda Chen

Proceedings Volume 9218, 92181W (2014) https://doi.org/10.1117/12.2062210

KEYWORDS: Calibration, Sensors, MODIS, Reflectivity, Sun, Black bodies, Satellites, Long wavelength infrared, Solar energy, Infrared imaging

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Proceedings Article | 26 September 2014 Paper

Progress on Alternative Method of the on-orbit RVS Characterization for MODIS Reflective Solar Bands

H. Chen, X. Xiong, A. Angal, X. Geng, A. Wu

Proceedings Volume 9218, 92181K (2014) https://doi.org/10.1117/12.2061884

KEYWORDS: MODIS, Calibration, Reflectivity, Mirrors, Sensors, Algorithm development, Diffusers, Detection and tracking algorithms, Space operations, Spectral calibration

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MODIS Reflective Solar Bands (RSB) are calibrated on-orbit using its onboard calibrators, including a Solar Diffuser (SD), a Solar Diffuser Stability Monitor (SDSM), and a Spectroradiometric Calibration Assembly (SRCA). A Space View (SV) port is used to provide a background reference, and also facilitate near monthly lunar observations via a spacecraft roll. In every scan, the earth’s surface, SV and onboard calibrators are viewed via a two sided scan mirror, whose reflectance depends on the angles of the incidence (AOI) as well as the wavelength of the incident light. Response versus Scan angle (RVS) is defined as a dependence function of the scan mirror’s reflectance over AOI. An initial RVS for each RSB was measured prelaunch for both Terra and Aqua MODIS. Algorithms have been developed to track the on-orbit RVS variation using the measurements from the onboard calibrators, supplemented with the Earth View (EV) response from pseudo-invariant desert targets obtained at different AOI. The current approach, as implemented in Collection 6 (C6), uses EV responses from the Libyan desert sites to track the on-orbit RVS change. It strongly depends on the long-term temporal stability of the desert sites. As an effort to validate and, if necessary, to improve MODIS RSB RVS characterization for future applications, the MODIS Characterization Support Team (MCST) has developed and tested an alternative approach to monitor the on-orbit RVS change, using a response from a single desert site. The purpose of using data from one site is to avoid the impact of possible differences in the long-term temporal stability among multiple sites on the calculation of the on-orbit RVS. This paper updates recent progress in the formulation of the alternative RVS approach. Comprehensive comparisons were also performed with current C6 RVS results for both Terra and Aqua MODIS. Results demonstrate that this alternative method provides a supplemental means to track the on-orbit RVS for MODIS RSB.

Proceedings Article | 25 September 2014 Paper

Status of time-dependent response versus scan-angle (RVS) for Terra and Aqua MODIS reflective solar bands

Xu Geng, Amit Angal, Junqiang Sun, Hongda Chen, Aisheng Wu, Yonghong Li, Daniel Link, Xiaoxiong Xiong

Proceedings Volume 9218, 92181P (2014) https://doi.org/10.1117/12.2061098

KEYWORDS: MODIS, Calibration, Reflectivity, Algorithm development, Mirrors, Sensors, Detection and tracking algorithms, Diffusers, Visible radiation, Near infrared

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Proceedings Article | 16 October 2013 Paper

Status of MODIS on-orbit calibration and characterization

X. Xiong, B. Wenny, J. Sun, A. Angal, A. Wu, H. Chen, X. Geng, T. Choi, S. Madhavan, D. Link, W. Barnes, Vincent Salomonson

Proceedings Volume 8889, 88890U (2013) https://doi.org/10.1117/12.2028953

KEYWORDS: MODIS, Calibration, Sensors, Staring arrays, Long wavelength infrared, Mirrors, Space operations, Sensor calibration, Near infrared, Neodymium

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Proceedings Article | 23 September 2013 Paper

On-orbit radiometric stability assessment of MODIS thermal emissive bands with lunar observation

Zhipeng Wang, Xiaoxiong (Jack) Xiong, Hongda Chen, Sriharsha Madhavan

Proceedings Volume 8866, 886604 (2013) https://doi.org/10.1117/12.2024101

KEYWORDS: MODIS, Sensors, Calibration, Reflectivity, Black bodies, Staring arrays, Sun, Long wavelength infrared, Photovoltaics, Mercury cadmium telluride

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Proceedings Article | 23 September 2013 Paper

On-orbit calibration performance of MODIS TDI bands

Mike Chu, Junqiang Sun, Amit Angal, Hongda Chen, Xu Geng, Taeyoung Choi, Xiaoxiang (Jack) Xiong

Proceedings Volume 8866, 886605 (2013) https://doi.org/10.1117/12.2024864

KEYWORDS: Calibration, MODIS, Sensors, Signal detection, Mirrors, Satellites, Environmental monitoring, Diffusers, Reflectivity, Imaging systems

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SPIE Journal Paper | 22 May 2013

Terra and Aqua moderate-resolution imaging spectroradiometer collection 6 level 1B algorithm

Gary Toller, Xiaoxiong Xiong, Junqiang Sun, Brian Wenny, Xu Geng, James Kuyper, Amit Angal, Hongda Chen, Sriharsha Madhavan, Aisheng Wu

JARS, Vol. 7, Issue 01, 073557, (May 2013) https://doi.org/10.1117/12.10.1117/1.JRS.7.073557

KEYWORDS: MODIS, Calibration, Sensors, Reflectivity, Long wavelength infrared, Staring arrays, Data acquisition, Detection and tracking algorithms, Signal to noise ratio, Atmospheric sciences

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Proceedings Article | 28 November 2012 Paper

An overview of MODIS RSB calibration and look-up-table delivery process

A. Angal, H. Chen, T. Choi, X. Geng, J. Sun, B. Wenny, X. Xiong

Proceedings Volume 8528, 85280L (2012) https://doi.org/10.1117/12.977550

KEYWORDS: MODIS, Calibration, Sensors, Mirrors, Reflectivity, Neodymium, Diffusers, Signal to noise ratio, Space operations, Ions

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Proceedings Article | 28 November 2012 Paper

MODIS reflective solar bands calibration improvements in Collection 6

Junqiang Sun, Amit Angal, Xiaoxiong Xiong, Hongda Chen, Xu Geng, Aisheng Wu, Taeyoung Choi, Mike Chu

Proceedings Volume 8528, 85280N (2012) https://doi.org/10.1117/12.979733

KEYWORDS: MODIS, Sensors, Calibration, Mirrors, Reflectivity, Algorithm development, Diffusers, Detection and tracking algorithms, Short wave infrared radiation, Near infrared

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Proceedings Article | 19 November 2012 Paper

Overview of Aqua MODIS 10-year on-orbit calibration and performance

X. Xiong, B. Wenny, J. Sun, A. Angal, A. Wu, H. Chen, T. Choi, S. Madhavan, X. Geng, D. Link, Z. Wang, G. Toller, W. Barnes, V. Salomonson

Proceedings Volume 8533, 853316 (2012) https://doi.org/10.1117/12.973769

KEYWORDS: Calibration, MODIS, Sensors, Long wavelength infrared, Staring arrays, Near infrared, Sensor calibration, Reflectivity, Diffusers, Spectral calibration

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Proceedings Article | 15 October 2012 Paper

On-orbit performance of the MODIS reflective solar bands time-dependent response versus scan angle algorithm

J. Sun, X. Xiong, A. Angal, H. Chen, Xu Geng, A. Wu

Proceedings Volume 8510, 85100J (2012) https://doi.org/10.1117/12.930021

KEYWORDS: MODIS, Calibration, Mirrors, Reflectivity, Algorithm development, Sensors, Detection and tracking algorithms, Lamps, Solids, Space operations

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Proceedings Article | 15 October 2012 Paper

Recent progress of MODIS solar diffuser on-orbit degradation characterization

H. Chen, Z. Wang, J. Sun, A. Angal, X. Xiong

Proceedings Volume 8510, 85100I (2012) https://doi.org/10.1117/12.929705

KEYWORDS: MODIS, Calibration, Sensors, Sun, Diffusers, Reflectivity, Signal attenuation, Radiometry, Signal detection, Vignetting

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Proceedings Article | 12 October 2011 Paper

Alternative approach to characterize response versus scan-angle (RVS) for MODIS reflective solar bands

H. Chen, X. Xiong, A. Wu

Proceedings Volume 8176, 817612 (2011) https://doi.org/10.1117/12.898226

KEYWORDS: MODIS, Reflectivity, Mirrors, Calibration, Diffusers, Sensors, Spectral calibration, Polarization, Data processing, Space operations

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Proceedings Article | 14 October 2010 Paper

Time-dependent response versus scan angle and its uncertainty for MODIS reflective solar bands

J. Sun, X. Xiong, H. Chen, A. Angal, X. Geng, A. Wu

Proceedings Volume 7826, 782620 (2010) https://doi.org/10.1117/12.864735

KEYWORDS: MODIS, Calibration, Sensors, Mirrors, Reflectivity, Algorithm development, Diffusers, Signal to noise ratio, Aerospace engineering, Space operations

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Proceedings Article | 28 August 2010 Paper

MODIS calibration algorithm improvements developed for Collection 6 Level-1B

Brian Wenny, Junqiang Sun, Xiaoxiong Xiong, Aisheng Wu, Hongda Chen, Amit Angal, Taeyoung Choi, Na Chen, Sriharsha Madhavan, Xu Geng, James Kuyper, Liqin Tan

Proceedings Volume 7807, 78071F (2010) https://doi.org/10.1117/12.860892

KEYWORDS: MODIS, Sensors, Calibration, Algorithm development, Mirrors, Detection and tracking algorithms, Space operations, Temperature metrology, Data processing, Reflectivity

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Proceedings Article | 27 August 2010 Paper

Using lunar observations to assess Terra MODIS thermal emissive bands calibration

Xiaoxiong Xiong, Hongda Chen

Proceedings Volume 7807, 78070I (2010) https://doi.org/10.1117/12.859088

KEYWORDS: MODIS, Calibration, Sensors, Reflectivity, Mirrors, Diffusers, Black bodies, Flame detectors, Detection and tracking algorithms, Sensor calibration

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Proceedings Article | 21 August 2009 Paper

MODIS solar diffuser stability monitor: function and applications

Hongda Chen, Xiaoxiong Xiong

Proceedings Volume 7452, 745218 (2009) https://doi.org/10.1117/12.824747

KEYWORDS: Sensors, MODIS, Sun, Calibration, Diffusers, Reflectivity, Detection and tracking algorithms, Space operations, Mirrors

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Proceedings Article | 21 August 2009 Paper

Time-dependent response versus scan angle for MODIS reflective solar bands

J. Sun, X. Xiong, H. Chen, A. Angal, X. Geng, A. Wu

Proceedings Volume 7452, 745219 (2009) https://doi.org/10.1117/12.825168

KEYWORDS: MODIS, Sensors, Mirrors, Calibration, Reflectivity, Algorithm development, Space operations, Diffusers, Spectral calibration, Light sources

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Proceedings Article | 9 April 2007 Paper

Analysis and visualization of large complex attack graphs for networks security

Hongda Chen, Genshe Chen, Erik Blasch, Martin Kruger, Irma Sityar

Proceedings Volume 6570, 657004 (2007) https://doi.org/10.1117/12.720035

KEYWORDS: Visualization, Network security, Databases, Visual analytics, Analytical research, Information security, Defense and security, Data modeling, Navigation systems, Computer networks

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Showing 5 of 53 publications

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