Geology topics

P. Goryl

Publications and source records attributed to P. Goryl.

3 recordsLinked to original sources

USGS2010

Radiometric, geometric, and image quality assessment of ALOS AVNIR-2 and PRISM sensors

The Advanced Land Observing Satellite (ALOS) was launched on January 24, 2006, by a Japan Aerospace Exploration Agency (JAXA) H-IIA launcher. It carries three remote-sensing sensors: 1) the Advanced Visible and Near-Infrared Radiometer type 2 (AVNIR-2); 2) the Panchromatic Remote-Sensing Instrument for Stereo Mapping (PRISM); and 3) the Phased-Array type L-band Synthetic Aperture Radar (PALSAR). Within the framework of ALOS Data European Node, as part of the European Space Agency (ESA), the European Space Research Institute worked alongside JAXA to provide contributions to the ALOS commissioning phase plan. This paper summarizes the strategy that was adopted by ESA to define and implement a data verification plan for missions operated by external agencies; these missions are classified by the ESA as third-party missions. The ESA was supported in the design and execution of this plan by GAEL Consultant. The verification of ALOS optical data from PRISM and AVNIR-2 sensors was initiated 4 months after satellite launch, and a team of principal investigators assembled to provide technical expertise. This paper includes a description of the verification plan and summarizes the methodologies that were used for radiometric, geometric, and image quality assessment. The successful completion of the commissioning phase has led to the sensors being declared fit for operations. The consolidated measurements indicate that the radiometric calibration of the AVNIR-2 sensor is stable and agrees with the Landsat-7 Enhanced Thematic Mapper Plus and the Envisat MEdium-Resolution Imaging Spectrometer calibration. The geometrical accuracy of PRISM and AVNIR-2 products improved significantly and remains under control. The PRISM modulation transfer function is monitored for improved characterization.

IEEE Transactions on Geoscience and Remote Sensing↗

USGS2010

The CEOS Cal/Val portal: A new instrument for the Cal/Val community

The exploitation of Earth Observation data depends with increasing importance on multi-source inter-calibrated data, as demonstrated, for example, in the ESA DUE GlobColour project. 1 The subgroup on Calibration and Validation of the Committee on Earth Observing System (CEOS) formulated a recommendation during the plenary session held in China at the end of 2004, with the goal of setting-up and operating an Internet based system to provide sensor data, protocols and guidelines for the purposes of efficiently supporting sensor calibration, inter-calibration and product validation. ESA has taken the initiative and launched the version 1.0 of the Cal/Val Portal in October 2006 and the version 2.0 in mid 2009. This paper describes the Cal/Val portal webpage, components, and general content organization. It also gives an example of collaboration and Cal/Val facility.

Conference Paper↗

USGS2008

Preliminary radiometric calibration assessment of ALOS AVNIR-2

This paper summarizes the activities carried out in the frame of the data quality activities of the Advanced Visible and Near Infrared Radiometer type 2 (AVNIR-2) sensor onboard the Advanced Land Observing Satellite (ALOS). Assessment of the radiometric calibration of the AVNIR-2 multi-spectral imager is achieved via three intercomparisons to currently flying sensors over the Libyan desert, during the first year of operation. All three methodologies indicate a slight underestimation of AVNIR-2 in band 1 by 4 to 7 % with respect to other sensors radiometric scale. Band 2 does not show any obvious bias. Results for band 3 are affected by saturation due to inappropriate gain setting. Two methodologies indicate no significant bias in band 4. Preliminary results indicate possible degradations of the AVNIR-2 channels, which, when modeled as an exponentially decreasing functions, have time constants of respectively 13.2 %.year -1 , 8.8 %.year -1 and 0.1 %.year -1 in band 1, 2 and 4 (with respect to the radiometric scale of the MEdium Resolution Imaging Spectrometer, MERIS). Longer time series of AVNIR-2 data are needed to draw final conclusions.

Conference Paper↗