Overview

NASA and Centre National D'Études Spatiales (CNES) have jointly established and will operate SWOT's Ground Systems, including all facilities required to operate the satellite; acquire its telemetry; and process, distribute and archive data products. The description below covers Satellite Operations and Science Data Processing during the Science Data Collection phase of the mission, approximately six months after launch.

Satellite Operations

Through S-band command and telemetry links with the SWOT Spacecraft Bus, CNES's Satellite Control Center in Toulouse (France) will oversee satellite control and operations. Twice per day, data will be linked through the CNES S-band network, including ground stations in Inuvik (Canada), Kiruna (Sweden), Hartebeesthoek (South Africa), Kourou (French Guyana), and Kerguelen Island (Indian Ocean). CNES will monitor its instruments from France. NASA instruments will be monitored from the instrument control center at the NASA Jet Propulsion Laboratory (JPL) in Pasadena, California (US).

Science Data Processing

About 21 times per day, ground stations will receive X-band downlink from SWOT's Payload Module. These science data files will be distributed by CNES to JPL's Payload Operations Center. The bulk of the science data will be from the Ka-band Radar Interferometer (KaRIn) instrument.

Over the ocean, KaRIn will process the incoming radar signal from an interferometric channel pair and generate a complex interferogram – as well as amplitude images for each channel – to be downlinked. The onboard processor will also perform multi-look averaging to decrease the data rate over the oceans prior to downlink. Data acquired over land will undergo standard synthetic aperature radar (SAR) compression. These minimally compressed data will be acquired within a land mask covering about 86% of continental surfaces between 78° N and 78° S latitude (excluding Antarctica).

Nominal science and research products, which will be released within 60 days of data acquisition, will be processed by both NASA and CNES and then distributed to operational users.

SWOT Data Products for Public Distribution

(from KaRIn unless otherwise noted*)

NASA PO.DAAC SWOT Page ›
AVISO SWOT Data Products Page ›

Low-Rate (Ocean) Interferogram Data Product *Radiometer Brightness Temperatures and Troposphere Data Product (including Operational and Interim)
Sea Surface Height Data Product (Native and Earth-Fixed Grid) Floodplain Digital Elevation Map Data Product
Single-look Complex Data Product Water Mask Raster Image Data Product
Water Mask Pixel Cloud Data Product River Cycle-Averaged Data Product
River Single-Pass Vector Data Product Lake Cycle-Averaged Data Product
Lake Single-Pass Vector Data Product *Nadir Altimeter Geophysical Data Record with Waveforms (including Operational and Interim)

Mission System Architecture

JPL-CNES mission system architecture flowchart.
JPL-CNES mission system architecture flowchart.

Resources

Discharge Data Products and Mission Operations
(2018), Durand, M.

Pixel Cloud Data Product Status
(2018), Williams, B.

+ see more

River Vector Product Status
(2018), Frasson, R., Durand, M., Callahan, P., Turk, J., Pottier, C., Biancamaria, S., Williams, B., and Wei, R.

Lake Data Product Status
(2018), Pottier, C., Biancamaria, S., Callahan, P., Turk, J., Durand, M., and Frasson, R.

SWOT Raster: Update
(2018), Pavelsky, T., and Zhang, S.

Science Data Processing Overview
(2018), Chen, C., Steunou, N., and Fjørtoft, R.

SWOT Ocean Product Status
(2018), Steunou, N. and Callahan, P.

Hydrology Products Status
(2018), Pottier, C., and Turk, J.

PO.DAAC - Plans for SWOT Data Access
(2018), Vannan, S., Gangl, M., Gierach, M., Hausman, J., McAuley, M., Oaida, C., and Stavros, E.N.

SWOT Ancillary Data, Auxiliary Data and Models
(2018), Desai, S. and Picot, N.

SWOT Short Latency Science Data Products: Status and Expected Performance
(2018), Picot, N. and Desai, S.

Status of Hydrology Simulator
(2018), Williams, B.

Large Scale Pixel Cloud Simulator and Hydrology Toolbox
(2018), Desroches, D., Pottier, C., Blumstein, D., Biancamaria, S., Poughon, V., and Fjørtoft, R.

Lake Products from LOCNES
(2018), Pottier, C. and Cazals, C.

Pixel Cloud Data Product Status
(2017), Williams, B. and Fjørtoft, R.

Lake Data Products Status
(2017), Pottier, C.

River Data Product Status
(2017), Durand, M., Frasson, R., Wei, R.

Raster Data Product Status
(2017), Pavelsky, T., Pottier, C., and Fjørtoft, R.

L2 LR Products
(2017), Callahan, P. and Steunou, N. PDF

Hydrology Data Products: Current Status and On-Going Work
(2017), Pottier, C., Callahan, P., Durand, M., Pavelsky, T., Biancamaria, S., and Cretaux, J-F.

Plans for SWOT Data Access
(2017), Vadon, H. and Hausman, J.

Science Data System Processing Overview
(2017), Chen, C., Steunou, N., and Fjørtoft, R.

Science Team Review of Algorithm Theoretical Basis Documents
(2017), Desai, S. and Picot, N.