U.S. Geological Survey (USGS) Landsat Ground Stations

Two ground stations in South Dakota and Australia serve as the primary data capture facilities for the USGS Landsat satellite image archive.

	The Landsat Ground Station (LGS) is located at the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center in Sioux Falls, South Dakota.
	The Alice Springs (ASN) site is located at the Geoscience Australia facility in Alice Springs, Australia.

These sites receive both the science data (via X-band Radio Frequency (RF) link) and the spacecraft housekeeping data (via S-band RF link). LGS also provides tracking services and a command link to the spacecrafts.

LGS and ASN send all housekeeping data to the Mission Operations Centers (MOCs) in realtime for immediate health and safety monitoring. Science data are sent to the Landsat 7 Processing System (LPS) or the Landsat Archive Conversion System (LACS) to process either the Landsat 7 or Landsat 5 data, respectively. Both systems are located in the LGS in Sioux Falls.

The NASA Tracking Data and Relay Satellite System (TDRSS) also provides housekeeping support for L7.

Two additional ground receiving stations, located in Poker Flat Alaska (DataLynx) and Svalbard Norway (SGS), are used as backup sites in times when extra ground resources are necessary to fulfill mission objectives.

All ground sites are equipped with 9-11 meter antennas and are capable of receiving both S-band (Housekeeping) and X-band (Science) data simultaneously. Housekeeping data are downlinked to the ground sites at 4 Kbps for Landsat 7 and 8 Kbps for Landsat 5.

Science Data Handling

Landsat 7 science data are downlinked at either 150 or 300 Mbps (2 x 150 Mbps) to the ground sites. Each 150 Mbps stream is made up of 75 Mbps In-Phase Channel (I) and Quadrature Channel (Q) and downlinked at different X-band frequencies. Landsat 5 science data are downlinked at 85 Mbps on a single X-band frequency. The Landsat 5 science data consist of only the I channel. Science data downlinked to ASN are captured on tape and shipped to LGS. LGS forwards all received data (either real-time or via tape) to the Landsat Processing System (LPS) or Landsat Archive Conversion System (LACS).