A Toolkit for CryoSat Investigations by the ESA-ESRIN EOP...
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EOP-SER DATA ARCHIVE STATUS The total amount of archived FBR (SAR/SARin) data is over 9 Terabytes. The archive includes normal processed data (CS_OFFL) and re-processed data (CS_RPRO). The normal processed data (CS_OFFL_) span from Jan. 2011 to Feb. 2013. The reprocessed data (CS_RPRO_) have just started to be collected (Jul. 2010). A local L1B archive (2011-2012), just short of 900 Gigabytes, is also kept locally. THE IMPORTANCE OF SARIN The Toolkit is able to Delay-Doppler process raw FBR data and re-track the L1b multi-looked Data even in SARin mode. The SARIn mode has a coarser precision with respect to SAR mode but is a very attractive operation mode in the coastal, land and inland-water scenario due to a broader receiving window (around 256 meters) that allows also to profile with more stability even the land surface s for moderate slope conditions. In the bottom picture, you see a SARIn pass over cuba where the instrument maintains the tracking over the full extension of the island profiling the land surface (coastal zone included). A Toolkit for CryoSat Investigations by the ESA-ESRIN EOP-SER R&D Altimetry Team S. Dinardo (SERCO/ESRIN), B. Lucas (Deimos/ESRIN), J. Benveniste (ESA-ESRIN) ABSTRACT The scope of this work is to feature the new tool (SARvatore: SAR Versatile Altimetric Toolkit for Ocean&Land Research and Exploitation) for the exploitation of the CryoSat data, designed and developed entirely by the Altimetry Team at ESA- ESRIN EOP-SER (Earth Observation – Exploitation, Research and Development). The framework is composed of two separate components: the first one handles the data collection and management, the second one is the processing toolkit. The CryoSat FBR (Full Bit Rate) data is downlinked uncompressed from the satellite, containing unaveraged individual echoes. This data is made available in the Kiruna CalVal server in a 10 day rolling archive. Daily at ESRIN all the CryoSat FBR data, in SAR and SARin Mode, are downloaded (around 30 Gigabytes) catalogued and archived in local ESRIN EOP-SER workstations. As of March 2013, the total amount of FBR data is over 9 Terabytes, with CryoSat acquisition dates spanning January 2011 to February 2013 (with some gaps). This archive was built by merging partial datasets available at ESTEC and NOAA, that have been gently made available to the EOP-SER team. The on-demand access to this low level data is restricted to expert users with validated ESA P.I. credentials. Currently the main users of the archiving functionality are the team members of the CP4O Project (CryoSat Plus for Ocean), CNES and NOAA. The second component of the service is the processing toolkit. On the EOP-SER workstations there is internally and independently developed software that is able to process the FBR data in SAR/SARin mode to generate multi-looked echoes (Level 1B) and subsequently able to re-track them in SAR and SARin mode (Level 2) over open ocean, exploiting the SAMOSA model and other internally developed models. The processing segment is used for research & development scopes, supporting the development contracts awarded confronting the deliverables to ESA, on site demonstrations/training to selected users, cross-comparison against third party products (CLS/CNES CPP Products for instance), preparation for Sentinel-3 mission, publications, etc. Samples of these experimental SAR/SARin L1b/L2 Products can be provided to the scientific community for comparison with self-processed data, on-request. So far, the processing has been designed and optimized for open ocean studies and is fully functional only over this kind of surface but there are plans to augment this processing capacity over coastal zones, inland waters and over land in sight of maximizing the exploitation of the upcoming the Sentinel-3 Topographic mission over all surfaces. There are also plans to make the toolkit fully accessible through software “gridification” to run in the ESA-ESRIN GPod (Grid Processing on Demand) Service and to extend the tool’s functionalities to support Sentinel-3 Mission (Simulated and Real Data). In this presentation, are shown graphs and statistics about the spatial coverage and amount of FBR data actually archived on the EOP-SER workstations, some scientific results and the tests that have been designed and performed to validate the products (tests against CryoSat Kiruna PDGS Products and against transponder data). Acknowledgments and References [1] R. K. Raney, "The Delay Doppler radar altimeter," IEEE Transactions on Geoscience and Remote Sensing, vol. 36, pp. 1578-1588, 1998 [2] Jensen J.R. and Raney R.K. “Delay/Doppler Radar Altimeter: Better Measurement Precision”, Geosci. and Remote Sensing Symposium Proceedings, 1998 [4] CryoSat Product Handbook. April 2012. ESA and Mullard Space Science Laboratory – University College London [3] Cullen, R. A., Wingham, D. et al., ESA’s CryoSat-2 Multi-Mode Level 0 to Level 1b Science Processors–Algorithm Design and Pre-Launch Verification with ASIRAS, Proceedings of the Envisat Symposium 2007 “, Montreux, SP-636,ESA. PERFORMANCE CURVES OVER OPEN SEA SURFACE CONCLUSIONS & WAY FORWARD The ESA-ESRIN/EOP-SER Toolkit Framework for the exploitation of CryoSat data has been presented along with some relevant results over sea surface, coastal zone wetland and even land . The dataset archive is over 9 TB and spans from January 2011 to February 2013. The precision performances of the toolkit are very good in term of standard deviation over open sea (0.9 cm for SSH at SWH=2m) and the stacking operation is as much accurate as half centimeter. Different stacking approaches have been developed in order to not lose the signal’s lock or cut useful data also on slopy surfaces in SAR and SARin mode. The L2 results over sea surfaces are now about to undergo a validation exercise against in situ measurements to detect any eventual biases or drifts. The usage of the toolkit will be crucial for the preparation and exploitation of the Sentinel-3 Mission and there are plans for its griddification through ESA GPod Service. For further information, please contact: [email protected], [email protected], [email protected]. In this box, the 1 Hz measurement precision for Sea Surface Height (SSH) and Significant Wave Height (SWH) and wind speed (U10) as function of the Significant Wave height at the German Bight are displayed. The EOP-SER Toolkit scored a SSH precision of 0.9 cm at SWH=2 m and a 6.5 cm SWH precision at SWH=2 m and U10 precision of 6 cm/sec at SWH=2 m. These metrics are relative to open sea conditions (distance to coast larger than 10 km). THE SAR MODE PROCESSING SAR MODE OVER LAND AND WETLAND A new stacking approach has been developed to obtain as much signal as possible even over slopy surfaces, in SAR/SARin mode. In the box, we show a CryoSat-2 SAR Radar Image (Radar Echogram) over Vietnam and Cambodia Inland (bottom) along with the corresponding topographic elevation profile from ACE-2 GDEM. The main land topographic features are marked in black in the figure. CryoSat-2 has lost the lock of the surface only on the isolated extreme mountain peaks; besides that, it succeeded to replicate very well the morphology of the territory for moderate slope conditions In a SAR Processing, the operations that are the most delicate and that demand for a very high accuracy are the beam-forming and the stacking. A way to verify the quality of the data stacking operation is to perform an over- sampled stacking on a trasnponder data pass. In the bottom box, you see a picture showing that the data stacking (i.e. look alignment in range) is as much precise as half centimeter. CryoSat altimeter readings over the Danube River delta in eastern Romania (top image). The radar image shows different radar reflection intensities from the Black Sea, Danube Delta’s wetland and elevated land.. These readings are of unprecedented sharpness compared to previous altimeters.
Transcript of A Toolkit for CryoSat Investigations by the ESA-ESRIN EOP...
EOP-SER DATA ARCHIVE STATUS
The total amount of archived FBR (SAR/SARin) data is over 9 Terabytes. The archive includes normal processed data (CS_OFFL) and re-processed data (CS_RPRO). The normal processed data (CS_OFFL_) span from Jan. 2011 to Feb. 2013. The reprocessed data (CS_RPRO_) have just started to be collected (Jul. 2010). A local L1B archive (2011-2012), just short of 900 Gigabytes, is also kept locally.
THE IMPORTANCE OF SARIN
The Toolkit is able to Delay-Doppler process raw FBR data and re-track the L1b multi-looked Data even in SARin mode. The SARIn mode has a coarser precision with respect to SAR mode but is a very attractive operation mode in the coastal, land and inland-water scenario due to a broader receiving window (around 256 meters) that allows also to profile with more stability even the land surface s for moderate slope conditions. In the bottom picture, you see a SARIn pass over cuba where the instrument maintains the tracking over the full extension of the island profiling the land surface (coastal zone included).
A Toolkit for CryoSat Investigations by the ESA-ESRIN EOP-SER R&D Altimetry Team
S. Dinardo (SERCO/ESRIN), B. Lucas (Deimos/ESRIN), J. Benveniste (ESA-ESRIN)
ABSTRACT
The scope of this work is to feature the new tool (SARvatore: SAR Versatile Altimetric Toolkit for Ocean&Land Research and Exploitation) for the exploitation of the CryoSat data, designed and developed entirely by the Altimetry Team at ESA-ESRIN EOP-SER (Earth Observation – Exploitation, Research and Development).
The framework is composed of two separate components: the first one handles the data collection and management, the second one is the processing toolkit. The CryoSat FBR (Full Bit Rate) data is downlinked uncompressed from the satellite, containing unaveraged individual echoes. This data is made available in the Kiruna CalVal server in a 10 day rolling archive. Daily at ESRIN all the CryoSat FBR data, in SAR and SARin Mode, are downloaded (around 30 Gigabytes) catalogued and archived in local ESRIN EOP-SER workstations.
As of March 2013, the total amount of FBR data is over 9 Terabytes, with CryoSat acquisition dates spanning January 2011 to February 2013 (with some gaps). This archive was built by merging partial datasets available at ESTEC and NOAA, that have been gently made available to the EOP-SER team.
The on-demand access to this low level data is restricted to expert users with validated ESA P.I. credentials. Currently the main users of the archiving functionality are the team members of the CP4O Project (CryoSat Plus for Ocean), CNES and NOAA.
The second component of the service is the processing toolkit. On the EOP-SER workstations there is internally and independently developed software that is able to process the FBR data in SAR/SARin mode to generate multi-looked echoes (Level 1B) and subsequently able to re-track them in SAR and SARin mode (Level 2) over open ocean, exploiting the SAMOSA model and other internally developed models. The processing segment is used for research & development scopes, supporting the development contracts awarded confronting the deliverables to ESA, on site demonstrations/training to selected users, cross-comparison against third party products (CLS/CNES CPP Products for instance), preparation for Sentinel-3 mission, publications, etc.
Samples of these experimental SAR/SARin L1b/L2 Products can be provided to the scientific community for comparison with self-processed data, on-request. So far, the processing has been designed and optimized for open ocean studies and is fully functional only over this kind of surface but there are plans to augment this processing capacity over coastal zones, inland waters and over land in sight of maximizing the exploitation of the upcoming the Sentinel-3 Topographic mission over all surfaces.
There are also plans to make the toolkit fully accessible through software “gridification” to run in the ESA-ESRIN GPod (Grid Processing on Demand) Service and to extend the tool’s functionalities to support Sentinel-3 Mission (Simulated and Real Data).
In this presentation, are shown graphs and statistics about the spatial coverage and amount of FBR data actually archived on the EOP-SER workstations, some scientific results and the tests that have been designed and performed to validate the products (tests against CryoSat Kiruna PDGS Products and against transponder data).
Acknowledgments and References
[1] R. K. Raney, "The Delay Doppler radar altimeter," IEEE Transactions on Geoscience and Remote Sensing, vol. 36, pp. 1578-1588, 1998 [2] Jensen J.R. and Raney R.K. “Delay/Doppler Radar Altimeter: Better Measurement Precision”, Geosci. and Remote Sensing Symposium Proceedings, 1998 [4] CryoSat Product Handbook. April 2012. ESA and Mullard Space Science Laboratory – University College London [3] Cullen, R. A., Wingham, D. et al., ESA’s CryoSat-2 Multi-Mode Level 0 to Level 1b Science Processors–Algorithm Design and Pre-Launch Verification with ASIRAS, Proceedings of the Envisat Symposium 2007 “, Montreux, SP-636,ESA.
PERFORMANCE CURVES OVER OPEN SEA SURFACE
CONCLUSIONS & WAY FORWARD The ESA-ESRIN/EOP-SER Toolkit Framework for the exploitation of CryoSat data has been presented along with some relevant results over sea surface, coastal zone wetland and even land . The dataset archive is over 9 TB and spans from January 2011 to February 2013. The precision performances of the toolkit are very good in term of standard deviation over open sea (0.9 cm for SSH at SWH=2m) and the stacking operation is as much accurate as half centimeter. Different stacking approaches have been developed in order to not lose the signal’s lock or cut useful data also on slopy surfaces in SAR and SARin mode. The L2 results over sea surfaces are now about to undergo a validation exercise against in situ measurements to detect any eventual biases or drifts. The usage of the toolkit will be crucial for the preparation and exploitation of the Sentinel-3 Mission and there are plans for its griddification through ESA GPod Service. For further information, please contact: [email protected], [email protected], [email protected].
In this box, the 1 Hz measurement precision for Sea Surface Height (SSH) and Significant Wave Height (SWH) and wind speed (U10) as function of the Significant Wave height at the German Bight are displayed. The EOP-SER Toolkit scored a SSH precision of 0.9 cm at SWH=2 m and a 6.5 cm SWH precision at SWH=2 m and U10 precision of 6 cm/sec at SWH=2 m. These metrics are relative to open sea conditions (distance to coast larger than 10 km).
THE SAR MODE PROCESSING
SAR MODE OVER LAND AND WETLAND
A new stacking approach has been developed to obtain as much signal as possible even over slopy surfaces, in SAR/SARin mode. In the box, we show a CryoSat-2 SAR Radar Image (Radar Echogram) over Vietnam and Cambodia Inland (bottom) along with the corresponding topographic elevation profile from ACE-2 GDEM. The main land topographic features are marked in black in the figure. CryoSat-2 has lost the lock of the surface only on the isolated extreme mountain peaks; besides that, it succeeded to replicate very well the morphology of the territory for moderate slope conditions
In a SAR Processing, the operations that are the most delicate and that demand for a very high accuracy are the beam-forming and the stacking. A way to verify the quality of the data stacking operation is to perform an over-sampled stacking on a trasnponder data pass. In the bottom box, you see a picture showing that the data stacking (i.e. look alignment in range) is as much precise as half centimeter.
CryoSat altimeter readings over the Danube River delta in eastern Romania (top image). The radar image shows different radar reflection intensities from the Black Sea, Danube Delta’s wetland and elevated land.. These readings are of unprecedented sharpness compared to previous altimeters.
