ESA CryoVEx 2014 Airborne ASIRAS radar and laser scanner measurements during 2014 CryoVEx campaign in the Arctic S. M. Hvidegaard, J. E. Nielsen, L. Sandberg Sørensen, S. B. Simonsen, H. Skourup, R. Forsberg, V. Helm, and T. Bjerg National Space Institute (DTU Space) Technical University of Denmark November 2015 EUROPEAN SPACE AGENCY CONTRACT REPORT ESA Contract No. 4000110600/14/NL/FF/lf ESA CryoVEx 2014 Airborne ASIRAS radar and laser scanner measurements during 2014 CryoVEx campaign in the Arctic Authors: S. M. Hvidegaard1, J. E. Nielsen1, S. L. Sandberg Sørensen1, S. B. Simonsen1, H. Skourup1, R. Forsberg1, V. Helm2, and T. Bjerg1 1 National Space Institute, DTU Space, Denmark 2 Alfred Wegener Institute for Polar and Marine Research, Germany DTU Space National Space Institute Danish Technical University Technical Report, 2015 ISBN‐978‐87‐91694‐26‐4 http://www.space.dtu.dk ESA STUDY CONTRACT REPORT ESA CONTRACT NO SUBJECT CONTRACTOR 4000110600/14/NL/FF/lf Technical Support for airborne ASIRAS and laser National Space Institute scanner measurements during 2014 CryoVEx (DTU Space) campaign in the Arctic ESA CR No STAR CODE No of volumes 1 CONTRACTORS This is Volume No 1 REFERENCE CryoVEx 2014 ABSTRACT This report outlines the airborne field operations with the ESA airborne Ku‐band interferometric radar (ASIRAS), coincident airborne laser scanner (ALS) and vertical photography to acquire data over sea‐ and land ice along validation sites and CryoSat‐2 ground tracks. The airborne campaign was coordinated by DTU Space using the Norlandair Twin Otter (TF‐POF). The campaign consisted of two experiment periods: Mid‐march to early April and late April to mid‐May with focus on sea ice and land ice, respectively. The sea ice measurements covered several validation sites with sea ice camps located in the Beaufort Sea lead by US office of Naval Research (ONR) and north of Greenland as a dedicated ESA CryoVEx initiative. In addition, selected CryoSat‐2 ground tracks were under‐flown in the Lincoln Sea from CFS Alert, North of Greenland and Svalbard from St. Nord and Longyearbyen. Several of the flights in the Beaufort and Lincoln Sea were coordinated with Uni. of York (UY) lead Basler aircraft towing an electromagnetic (AEM/EM bird) sounder to obtain sea ice thickness and Operation IceBridge (OIB) NASA P‐3 carrying a variety of instruments for sea ice and snow retrievals. Land ice measurements were acquired over the Greenland ice sheet (the EGIG line and selected CryoSat‐ 2 ground tracks), together with Austfonna and Devon ice caps. At Austfonna and Devon ice caps ground teams measured ice and snow properties, and raised corner reflectors acting as a surface reference point in order to estimate the penetration depth of the ASIRAS radar. An opportunity site on the Greenland Ice Sheet was surveyed near Jakobshavn Isbræ. No other ground experiments were coordinated with the CryoVEx campaing on the Greenland Ice Sheet. The CryoVEx 2014 campaign was a success and the processed data is of high quality. The data set includes 13 CryoSat underflights covering distances from 25‐560 km. The preliminary comparisons to CryoSat‐2 data show the potential of the extensive dataset. The work described in this report was done under ESA Contract. Responsibility for the contents resides in the author or organisation that prepared it. Names of authors: S. M. Hvidegaard, J. E. Nielsen, S. L. Sandberg Sørensen, S. B. Simonsen, H. Skourup, R. Forsberg, V. Helm, and T. Bjerg NAME OF ESA STUDY MANAGER ESA BUDGET HEADING Tânia Casal Mission Science Division Validation Campaigns ‐ ESTEC Contents 1 Introduction ..................................................................................................................................... 4 2 Summary of operation .................................................................................................................... 7 2.1 Day to day .............................................................................................................................. 10 3 Hardware installation .................................................................................................................... 12 4 Overview of acquired data ............................................................................................................ 16 5 Processing ...................................................................................................................................... 20 5.1 GPS data processing .............................................................................................................. 20 5.2 Inertial Navigation System .................................................................................................... 22 5.3 Airborne Laser Scanner (ALS) ................................................................................................ 24 5.3.1 Calibration ..................................................................................................................... 24 5.3.2 Laser scanner outlier detection and removal ................................................................ 25 5.3.3 Statistical consequences: .............................................................................................. 26 5.3.4 Cross‐over statistics ....................................................................................................... 26 5.4 ASIRAS ................................................................................................................................... 29 5.4.1 CryoVEx 2014 ASIRAS processing results ...................................................................... 29 5.4.2 Runway over flights and comparison with ALS‐DEM .................................................... 30 5.4.3 Corner reflector over flights .......................................................................................... 33 5.5 Vertical images ...................................................................................................................... 35 6 Calibration and Validation sites ..................................................................................................... 37 6.1 Sea ice .................................................................................................................................... 38 6.2 Land ice .................................................................................................................................. 44 6.2.1 Austfonna ice cap .......................................................................................................... 44 6.2.2 Devon ice cap ................................................................................................................ 46 6.2.3 Greenland Ice Sheet ...................................................................................................... 47 7 Conclusion ..................................................................................................................................... 49 8 Reference ...................................................................................................................................... 50 1 APPENDIX Operator logs ............................................................................................................... 51 2 APPENDIX Airport codes ................................................................................................................ 81 3 APPENDIX Coordinates of GPS base stations ................................................................................ 82 Final Report Page | 2 4 Appendix – Overview of acquired ALS data .................................................................................. 83 5 Appendix – Overview of acquired ASIRAS log‐files ....................................................................... 86 6 APPENDIX ESA File name convention ESA data format................................................................. 89 7 APPENDIX ESA data format ........................................................................................................... 90 7.1 ASIRAS L1b ............................................................................................................................. 90 7.2 GPS ...................................................................................................................................... 103 7.3 INS ....................................................................................................................................... 104 7.4 Laser scanner (ALS) .............................................................................................................. 105 7.5 Vertical Camera ................................................................................................................... 106 8 APPENDIX Processed GPS data in ESA format ............................................................................. 107 9 APPENDIX Processed INS data in ESA format .............................................................................. 108 10 APPENDIX Processed ALS data in ESA format ......................................................................... 109 11 APPENDIX Time‐tagged and geo‐located images .................................................................... 112 12 APPENDIX Processed ASIRAS profiles ...................................................................................... 117 CryoVEx 2014 airborne field campaign Page | 3 1 Introduction In continuation of the CryoSat‐2 Validation