1 / 16

Recent Activities of Ocean Surface Topography Virtual Constellation (OST-VC)

Recent Activities of Ocean Surface Topography Virtual Constellation (OST-VC). Remko Scharroo (EUMETSAT). OST-VC — Background. Satellite altimeter launches since 2016 Fully operational Jason-3 (Jan 2016) Sentinel-3A (Feb 2016) Sentinel-3B (Apr 2018) In commissioning HY-2B (Oct 2018)

cruth
Download Presentation

Recent Activities of Ocean Surface Topography Virtual Constellation (OST-VC)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Recent Activities of Ocean Surface Topography Virtual Constellation(OST-VC) • Remko Scharroo (EUMETSAT)

  2. OST-VC — Background • Satellite altimeter launches since 2016 • Fully operational • Jason-3 (Jan 2016) • Sentinel-3A (Feb 2016) • Sentinel-3B (Apr 2018) • In commissioning • HY-2B (Oct 2018) • CFOSAT (Oct 2018) • Long-term (25+ years) altimeter record • Cross-calibration and reprocessing • In-situ data • Various initiatives and projects

  3. OSTST • Ocean Surface Topography Science Team (OSTST) • Is expanding to become a multi-mission international working group on all altimeter missions • Wide range of scientists and operational users with interest in Jason / altimetry missions • Sponsored by all Jason Partner agencies (CNES, NASA, NOAA, EUMETSAT) and ESA • Decision making on data processing algorithms and standards, reprocessing, validation protocols • Commissioning data releases to OSTST PIs for review prior to release to wider community • Mission-long cal/val activities

  4. S3B minus S3ASSHA in SAR Mode Excellent consistency Std of difference only 3.5 cm SSHA Bias is -7 mm (S3B below S3A) Slight dependency of the difference with the sea state Basin Scale Errors ? (waiting for better orbits) Tracks Visible

  5. Jason-2 End-of-life • Small group of experts made recommendations to optimise between constellation needs and science output • Decision making by Joint Steering Group (Partner Agencies) • Currently in geodetic orbit with spatial resolution of 4 km (2 km planned) • To improve detail and accuracy in mean sea surface topography as reference for future missions • To improve knowledge of ocean bottom topography and map tens of thousands of unknown sea mounts

  6. Jason-3 overall status • Reference altimeter mission • Jason-3 is now the reference mission for the monitoring of global and regional sea level rise • Cross-calibratedwith Jason-2 to1-mm level

  7. Sentinel-3 Missions (1) • In-orbit verification, calibration and validation • Conducted largely by Partner Agencies (ESA, EUMETSAT, CNES) • Decision making on data release to S3VT and wider community • Sentinel-3 Validation Team (S3VT) • Wide range of scientists and operational users with interest in Sentinel-3 • Meet approximately yearly to present cal/valresults and report on data quality/availability and areas of improvement • Suggestions for future evolutions of algorithms/auxiliary data and reprocessing

  8. Sentinel-3 Missions (2) • Sentinel-3 Quality Working Group (S3QWG) • Consists of select group of key scientists or operational users (e.g. CMEMS) on various aspects of satellite altimetry applications: • Sea level, sea ice, land ice, winds and waves, climate, geodesy • Reports on quality analysis • Recommends evolutions to Partner Agencies

  9. Sentinel-3 Missions (3) • CEOS OST-VC Highlight • At time of Sentinel-3A launch it was planned to launch Sentinel-3B directly into its interleaved orbit • So no tandem mission • ESA and EUMETSAT with the help of OST-VC recommended to management to have a tandem mission first • Common to previous altimeter missions for long-term record • Unique for optical instruments • Paid off in detecting small inter-satellite (processing) differences

  10. S3A/S3B Tandem Mission • Cross-calibration of SSH measurements • 3.5 cm RMS • –7 mm mean(to climatequality level)

  11. Sentinel-6/Jason-CS • Status • Satellite under integration and testing • System passed Critical Design Review • Processors under development • Organisation • Mission Performance Working Group (EUMETSAT, ESA, NASA, NOAA, CNES) reviewing product specifications and (in future) conduct cal/val and analyse product quality and evolutions • Integration in OSTST • Agencies are preparing call for participation of OSTST members in Sentinel-6 Validation Team • Team will have early access to commissioning data to do additional cal/val within their expertise and recommend evolutions • To be continued throughout mission lifetime

  12. FRM4ALT: Fiducial Reference Measurements for Altimetry • International Review Workshop (April 2018) • Critical review of methodology • Cal/Val using ground-based measurements • Define requirements, establish standards • Calibration such that sea level can be monitored under international standards • Roadmap • Establish reference frame • Minimum set of observations • Harmonised approach with continuous capability • Requirements on in-situ equipment • Transponder, tide-gauges, radiometer

  13. SAOO Phase 0 study • CNES Phase 0 study for new (swath) altimeter constellation • Based on requirement to resolve 50 km & 5 days resolution • Leads to either 15+ 1-D altimeters or 2-3 swath altimeters • Still needs “traditional” 1-D altimeters for reference • ESA Phase 0 study for Swath Altimeter for Operational Oceanography (SAOO) • To lead to establishment of User Requirement Document on SAOO • Study can be expanded to white paper on future overall altimeter constellation • Based on up-to-date requirements on • Spatio-temporal coverage • Accuracy • Long-term stability • Observations of sea ice, continental ice, and inland waters • Accounting for merging of wide swath with nadir altimeter constellation • Intended as OST-VC activity for next 2 years

  14. Contributing missions • CryoSat-2 • Providing ocean topography data since 2010 • Has been essential to the understanding of SAR altimetry in preparation of Sentinel-3 and Sentinel-6 • SARAL/AltiKa • Orbital altitude not maintained since 2016, relying on accurate mean sea surface for SSH anomaly measurements • CFOSAT • Nadir information will be useful for developing higher level products • Hai Yang 2 • HY2A: Moved to geodetic orbit in 2016 • HY2B: Under commissioning

  15. Summary • Best constellation of surface topography missions ever • Best constellation ever

  16. Challenges ahead • Wide swath and conventional altimetry • Integration of conventional altimetry and wide swath to optimum temporal/spatial resolution and operational needs • Future of reference missions • What after Sentinel-6B? • Noting that Sentinel-3A/B/C/D will have more than 15 years of overlap with reference missions

More Related