New CryoVEx campaign datasets released

08 Sep 2022

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Overview of the flight tracks from the CryoVEx/ICESat2 2019 airborne campaign in Greenland.

Two new datasets have been released for the CryoVEx campaign, covering activities in Spring and Summer 2019.

ESA conduct airborne and ground-based campaigns to support the development of new instruments, and calibration and validation of existing instruments. These campaigns simulate satellite-based instruments and are conducted all over the world in support of a wide range of applications.

CryoVEx (CryoSat Validation Experiment) is a series of campaigns conducted in support of the CryoSat mission. These airborne campaigns have taken place since 2003, validating CryoSat’s SIRAL instrument since before the satellite launched in 2010.

The 2019 campaigns additionally aimed to cross-validate CryoSat acquisitions with NASA’s ICESat-2 for the first time, following the launch of ICESat-2 in September 2018. This supports CRYO2ICE, a collaboration between ESA and NASA to operate CryoSat and ICESat-2 in coincident orbits. CRYO2ICE has been performed since 2020, offering near simultaneous data from the two satellites over the same locations in the Arctic until 2022, and currently the Antarctic.

The CryoVEx campaigns used the ASIRAS and KAREN instruments – Ku- and Ka-band radars, respectively – together with a Near-Infrared laser scanning altimeter (ALS) on a Twin Otter aircraft flying over sea and land ice in the Arctic. The purpose was to compare the data from these instruments, to simulate the data acquired by CryoSat and ICESat-2, and assess the feasibility of conducting dual-frequency polar satellite missions, such as the future Copernicus CRISTAL (Copernicus Polar Ice and Snow Topography Altimeter) mission.

During the Spring campaign, the aircraft performed a direct underflight of CryoSat in Baffin Bay, enabling an accurate comparison of data from ASIRAS with SIRAL. Poor weather prevented an underflight of ICESat-2 and so a second campaign was conducted in Summer to perform the underflight.

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KAREN Radio Frequency (RF) enclosure with updated microstrip patch antennas.

In addition, a new combined Ka- and Ku-band radar was used during the campaign. The combined radar was developed by the Center for Remote Sensing of Ice Sheets (CReSIS), and was used to test the feasibility of an instrument that was capable of acquiring radar data in both of the bands ASIRAS and KAREN use.

In the Summer campaign, which took place in August, the CReSIS instrument was used alone, without the individual ASIRAS and KAREN instruments used in the Spring campaign. The ALS was retained and used during the campaign. Underflights of both CryoSat and ICESat-2 were conducted successfully.

The Spring campaign showed high quality acquisitions with low mean differences and deviations between ALS and ASIRAS/KAREN when performing flights over flat surfaces such as the Greenland ice sheet and sea ice. Variation was much larger over runways, however, but to a degree consistent with previous CryoVEx campaigns that utilised both ASIRAS and KAREN.

The Summer campaign successfully demonstrated the CReSIS radar’s capability, acquiring dual-band altimeter measurements. However, the instrument was unable to support CryoSat’s SAR or SARIn modes, and so could not acquire this form of data from previous campaigns carrying ASIRAS and KAREN.

To address this, a form of along-track SAR processing was performed but this presented some challenges in acquisition, as it was not able to accurately determine surface locations as the full-bandwidth ASIRAS and KAREN instruments. The campaign team made recommendations in how to address this for future campaigns.

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Overview of instrument setup in the Norlandair

 

As the first CryoVEx campaigns conducted since the launch of ICESat-2, these flights gathered valuable cross-validation of CryoSat and ICESat-2, and tested the new combined Ka- and Ku-band instrument, demonstrating use for such instruments in future missions.

Following the conclusion of the campaigns, data acquired are freely offered for download following submission of a data access request. In addition, all historical data from the CryoVEx campaigns are available to download through the CS2EO portal. 

Learn more about the 2019 CryoVEx campaigns and how to request the data: