|Project: Jason-2 / Jason-3 Ocean Altimetry|
|NOAA Mission Goal: Weather & Water, Climate|
|Project Manager: (Jason Ground System) Angelo Wade, OSD Ground Systems Division|
Project Description: The Ocean Surface Topography Mission (OSTM) is a joint effort by four organizations to measure sea surface height by using a radar altimeter mounted on a polar-orbiting satellite called Jason-2*. The four mission partners are NOAA, France’s Centre National d’Etudes Spatiales (CNES), NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, and EUMETSAT. The figure below illustrates the connections among OSTM mission partners.
The objective of the operational OSTM / Jason-2 mission is to provide service continuity for the predecessor research programs Topex / Poseidon (1992) and Jason-1 (2001). The Jason-2 satellite was launched in June 2008, with a design lifetime of three years and an extended lifetime of two additional years.
For NOAA, the Jason-2 system implementation primarily entails transitioning the Jason-1 research and development satellite to an operational Jason-2 satellite system using the existing NOAA operational polar satellite ground segment. The Jason-2 ground system became operational in 2009 and is supported by GSD.
Jason-3* is planned as a follow-on for Jason-2, with NOAA providing a microwave radiometer, precision orbit determination components (e.g., Global Positioning System (GPS)), launch services, associated engineering services, the Jason-2 command and control, and data processing capabilities. EUMETSAT will provide the spacecraft, altimeter, precision orbit components, ground system and operations. NOAA and EUMETSAT will develop mission concept and determine roles and responsibilities for system acquisition, deployment and operations. GSD is currently engaged in planning for the support of Jason-3 using an operations concept similar to that employed for Jason-2. Launch of Jason-3 will be in FY 2013, allowing an overlap with the Jason-2 mission.
The general data flow for the Jason-2 ground system is shown in the diagram below. Raw telemetry data streams from the Jason platform are captured at NOAA’s Wallops and Fairbanks Command and Data Acquisition Stations (CDAS) and at EUMETSAT’s tracking station located at Usingen, Germany. These streams are then forwarded to other Jason-2 subsystems at NOAA’s Satellite Operations Control Center (SOCC, referenced as NOAA Spacecraft Operations in the diagram below) in Suitland, Maryland for further action.
A SOCC server functions as a centralized data exchange and distribution hub for data transfers between NOAA internal subsystems, and between NOAA and its partners. The Environmental Satellite Processing Center (ESPC), collocated with the SOCC in Suitland, generates near real-time operational data products using software provided by CNES. These products are made available to NASA/JPL, EUMETSAT and CNES via the centralized data server located at SOCC, and also staged to the ESPC primary data distribution server for dissemination to the general user community and to the NOAA long-term CLASS data archive. A similar process is followed at EUMETSAT for generation and delivery of operational data products to the partners. In addition, data products of improved accuracy are generated by CNES and distributed to NOAA and EUMETSAT in non-real-time fashion, usually with a latency of several days.
As shown in the figure, a bi-directional flow of data and information exists between the SOCC and EUMETSAT. The flow from SOCC to EUMETSAT includes the flow of Near-Real-Time operational products, stored payload telemetry, stored housekeeping and real-time housekeeping telemetry. The flow from EUMETSAT to SOCC includes spacecraft raw payload and housekeeping telemetry sent from the Usingen via the EUMETSAT communications network, offline (non-near real-time) geophysical data products generated by CNES, near real-time products generated by EUMETSAT, and earth station telemetry from Usingen.