Calval Evaluation of Desis Products in Amiaz Plain and Makhtesh Ramon Test Sites, Southern Israel

Abstract

Abstract. The new era of hyperspectral remote (HSR) sensors in orbit is approaching. Missions such as CHIME of the European Space Agency (ESA), EMIT/SBG of NASA, EnMAP of the German Aerospace Center (DLR), and SHALOM of the Israel Space Agency (ISA) will launch in the near future, while other HSR sensors are already in orbit, such as DESIS of DLR, PRISMA of the Italian Space Agency (ASI), and HISUI of the Japan Aerospace Exploration Agency (JAXA). Vicarious calibration (VC) of satellite sensors is vital to tracking a sensor's performance during its lifetime and is a routine procedure in any satellite mission. Accordingly, searching for ideal sites for CAL/VAL operation is an important task that should be part of the mission planning. This study demonstrates two areas in southern Israel that can be acquired in one overpass as VC sites: Amiaz Plain (AP) and Makhtesh Ramon (MR), which were evaluated for their fulfillment of all VC requirements for HSR sensors. AP (5 km2 of homogeneous bright target) was found suitable for radiometric calibration, and MR (200 km2) for spectral and thematic validations. We checked the applicability of these sites using a high-end airborne HRS sensor (AisaFENIX 1K sensor with 420 bands, 375–2500 nm spectral range, and 1.5-m spatial resolution) along with comprehensive field studies and ground measurements. Accordingly, we developed an operational VC protocol to use these sites for both radiometric and spectral quality inspection of HRS satellites. We demonstrated this capability on recent PRISMA and DESIS reflectance products. Here we provide these analyses and recommend how to use these areas to further examine DESIS data's performance. We call for collaborations with individuals and space agencies in using these VC sites, where we will provide ground-truth information and fulfill any other requirements for VC.

Calibration and Validation for the Surface Biology and Geology (SBG) Mission Concept: Recommendations for a Multi‐Sensor System for Imaging Spectroscopy and Thermal Imagery

“…In addition, minerals with strong, narrow absorption features at the Earth's surface could also serve as spectral calibration targets. Examples of such targets include the long‐utilized geologic remote sensing reference site at Cuprite, NV (Swayze et al., 2014) and the site at Makhtesh Ramon, Israel (Pearlshtien & Ben‐Dor, 2022; Pearlshtien et al., 2021). Fraunhofer lines appear in lunar or solar observations, in cloud and ice reflectance, or in specular reflectance off water.…”

An Accuracy Assessment of the Surface Reflectance Product from the EMIT Imaging Spectrometer

“…Alonso et al [4] compare reflectance products from the DESIS visible-near infrared (VNIR) imaging spectrometer to data from two RadCalNet-managed calibration sites, finding differences in absolute reflectance that are generally less than 2%. Heller Pearlshtein and Ben-Dor [7] compare DESIS data with ground measurements in a more topographically complex scene, finding errors exceeding 5% for some wavelength regions but generally good spectral agreement and accuracy in resulting mineral products. Storch et al [2] compare EnMAP imaging spectrometer data to ground reference spectra, and find one-sigma uncertainties between 1-4% depending on the surface cover and albedo.…”