• Ablain, M., Philipps S. , Picot N. , and Bronner E. , 2010: Jason-2 global statistical assessment and cross-calibration with Jason-1. Mar. Geod., 33 (Suppl.), 162185, doi:10.1080/01490419.2010.487805.

    • Search Google Scholar
    • Export Citation
  • Amarouche, L., Thibaut P. , Zanife O. , Dumont J.-P. , Vincent P. , and Steunou N. , 2004: Improving the Jason-1 ground retracking to better account for attitude effects. Mar. Geod., 27, 171197, doi:10.1080/01490410490465210.

    • Search Google Scholar
    • Export Citation
  • Bamber, J. L., Ekholm S. , and Krabill W. , 2001: A new, high-resolution digital elevation model for Greenland fully validated with airborne laser altimetry data. J. Geophys. Res., 106, 67336745, doi:10.1029/2000JB900365.

    • Search Google Scholar
    • Export Citation
  • Brown, G. S., 1977: The average impulse response of a rough surface and its applications. IEEE Trans. Antennas Propag., 25, 6774, doi:10.1109/TAP.1977.1141536.

    • Search Google Scholar
    • Export Citation
  • Carayon, G., Steunou N. , Courrière J.-L. , and Thibaut P. , 2003: Poseidon-2 radar altimeter design and results of in-flight performances. Mar. Geod., 26, 159165, doi:10.1080/714044516.

    • Search Google Scholar
    • Export Citation
  • Desjonquères, J., Carayon G. , Steunou N. , and Lambin J. , 2010: Poseidon-3 radar altimeter: New modes and in-flight performances. Mar. Geod., 33 (Suppl.), 5779, doi:10.1080/01490419.2010.488970.

    • Search Google Scholar
    • Export Citation
  • Dumont, J., and Coauthors, 2015: OSTM/Jason-2 products handbook. Tech. Rep., Version 1.9, CNES SALP-MU-M-OP-15815-CN, EUMETSAT EUM/OPS-JAS/MAN/08/0041, JPL OSTM-29-1237, NOAA/NESDIS Polar Series/OSTM J400, 65 pp. [Available online at http://www.aviso.altimetry.fr/fileadmin/documents/data/tools/hdbk_j2.pdf.]

  • Hayne, G. S., 1980: Radar altimeter mean return waveforms from near-normal-incidence ocean surface scattering. IEEE Trans. Antennas Propag., 28, 687692, doi:10.1109/TAP.1980.1142398.

    • Search Google Scholar
    • Export Citation
  • Helbert, J., and Coauthors, 2007: Generation of DEMs for the new tracking mode using DIODE real-time navigator information onboard Poseidon-3 and AltiKa. [Available online at http://www.aviso.altimetry.fr/fileadmin/documents/OSTST/2007/helbert.pdf.]

  • Lambin, J., Desjonquères J.-D. , Steunou N. , and Helbert J. , 2008: OSTM/Jason-2 and AltiKa new tracking modes. [Available online at http://cioss.coas.oregonstate.edu/CIOSS/workshops/Altimeter_workshop_08/Coastal_Alt_Presentations/21_Lambin_Jason-2_Tracking_Modes.pdf.]

  • Liu, H., Jezek K. , Li B. , and Zhao Z. , 2001: Radarsat Antarctic Mapping Project digital elevation model, version 2. NASA National Snow and Ice Data Center Distributed Active Archive Center, accessed 24 May 2016. [Available online at http://nsidc.org/data/nsidc-0082.]

  • Picot, N., Guillot A. , Desai S. , Haines B. , Bonekamp H. , Scharroo R. , Lillibridge J. , and Leuliette E. , 2015: Jason-3 calval plan. Tech. Rep. TP4-J0-PLS-1158-CNES, 68 pp.

  • Roca, M., Laxon S. , and Zeli C. , 2009: The EnviSat-RA2 instrument design and tracking performance. IEEE Trans. Geosci. Remote Sens., 47, 34893506, doi:10.1109/TGRS.2009.2020793.

    • Search Google Scholar
    • Export Citation
  • Thibaut, P., Poisson J. , Bronner E. , and Picot N. , 2010: Relative performance of the MLE3 and MLE4 retracking algorithms on Jason-2 altimeter waveforms. Mar. Geod., 33 (Suppl.), 317335, doi:10.1080/01490419.2010.491033.

    • Search Google Scholar
    • Export Citation
  • Tournadre, J., and Morland J. , 1997: The effects of rain on TOPEX/Poseidon altimeter data. IEEE Trans. Geosci. Remote Sens., 35, 11171135, doi:10.1109/36.628780.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 272 146 5
PDF Downloads 152 101 2

Evaluating the Performance of Jason-2 Open-Loop and Closed-Loop Tracker Modes

View More View Less
  • 1 Global Science and Technology, Inc., at NOAA/Laboratory for Satellite Altimetry, College Park, Maryland
  • | 2 NOAA/Laboratory for Satellite Altimetry, College Park, Maryland
  • | 3 isardSAT LTD, Guildford, Surrey, United Kingdom
Restricted access

Abstract

The Poseidon-3 altimeter on board Jason-2 includes a significant new capability with respect to its predecessors, an open-loop [Détermination Immédiate d’Orbite par Doris Embarqué (DIODE)/digital elevation model (DEM)] tracker mode. This innovative mode is capable of successfully tracking the backscatter signal over rapidly varying terrains, and thus it overcomes one of the limitations of the closed-loop Poseidon-2 tracker on board Jason-1. DIODE/DEM achieves this improvement thanks to a predetermined DEM on board that, when combined with DIODE orbit ephemeris, provides improved acquisition timing and reduced data loss in the coastal zone. As a further enhancement, Jason-3 and the Sentinel-3 programs will be capable of autonomously switching to this innovative mode in selected regions. To help recommend how these missions should utilize DIODE/DEM, the authors studied the impact of the tracker mode on the accuracy and precision of wave heights and wind speed, the continuity of the sea level climate data record, and the coverage in coastal regions. The results show close agreement between the open- and closed-loop tracker modes over the open ocean with the exception of some differences at high-tidal variability areas, the coastal zone, and sea ice regions. The DIODE/DEM tracker shows better performance than the closed-loop tracker mode at the coast and in the presence of sea ice. Jason-2, when operating in open-loop mode, allows for an approximately 5% increase of successful acquisitions at the ocean-to-land transition. However, open-loop tracking exhibits more variability in regions of high tides than closed-loop.

Corresponding author address: Cristina Martin-Puig, Global Science and Technology, Inc., at Laboratory for Satellite Altimetry, NOAA Center for Weather and Climate Prediction, 5830 University Research Court, College Park, MD 20740. E-mail: cmpuig@gmail.com

Abstract

The Poseidon-3 altimeter on board Jason-2 includes a significant new capability with respect to its predecessors, an open-loop [Détermination Immédiate d’Orbite par Doris Embarqué (DIODE)/digital elevation model (DEM)] tracker mode. This innovative mode is capable of successfully tracking the backscatter signal over rapidly varying terrains, and thus it overcomes one of the limitations of the closed-loop Poseidon-2 tracker on board Jason-1. DIODE/DEM achieves this improvement thanks to a predetermined DEM on board that, when combined with DIODE orbit ephemeris, provides improved acquisition timing and reduced data loss in the coastal zone. As a further enhancement, Jason-3 and the Sentinel-3 programs will be capable of autonomously switching to this innovative mode in selected regions. To help recommend how these missions should utilize DIODE/DEM, the authors studied the impact of the tracker mode on the accuracy and precision of wave heights and wind speed, the continuity of the sea level climate data record, and the coverage in coastal regions. The results show close agreement between the open- and closed-loop tracker modes over the open ocean with the exception of some differences at high-tidal variability areas, the coastal zone, and sea ice regions. The DIODE/DEM tracker shows better performance than the closed-loop tracker mode at the coast and in the presence of sea ice. Jason-2, when operating in open-loop mode, allows for an approximately 5% increase of successful acquisitions at the ocean-to-land transition. However, open-loop tracking exhibits more variability in regions of high tides than closed-loop.

Corresponding author address: Cristina Martin-Puig, Global Science and Technology, Inc., at Laboratory for Satellite Altimetry, NOAA Center for Weather and Climate Prediction, 5830 University Research Court, College Park, MD 20740. E-mail: cmpuig@gmail.com
Save