Landsat - Land Remote Sensing Satellite Program managed by the U.S. Geological Survey. The Landsat Satellite series began in 1972 to gather information about land surface features of the planet. Landsat 5, launched in 1984, and Landsat 7, launched in 1999, are still operational.

Data from the satellites have been used for monitoring land cover conditions, geological / mineralogical exploration, urban growth, and cartography. Global coverage is available and data sets are provided by the USGS at the cost of reproduction.

Landsat 7 Contact Period - The time duration between the start and end of raw wideband data transmissions from the Landsat 7 spacecraft to a ground station [e.g., the Landsat 7 Ground Station (LGS).

Latitude - The angular distance North or South from the Earth's equator measured in degrees with the equator at 0o and the poles 90o N and 90o S.

Level 0R Files - The generic term used to denote the grouping of band, MSCD, PCD, and calibration data files for a single subinterval.

Level 0R product - A US data product in which the data has been spatially reformatted but the data values remain unchanged. No radiometric or geometric corrections have been performed on the data. The reformatting is fully reversible. The data is band sequential. Attached to the image data are radiometric calibration image data, payload correction data, quality data, and metadata.

Level 0R Quality and Accounting Data - The data quality and accounting information collected by the Landsat 7 Processing System (LPS), on a subinterval basis, from processing of the ETM+ major frames constructed from the wideband Virtual Channel Data Units (VCDUs) received during a Landsat 7 contact period.

Longitude - The angular distance East or West between the meridian of a particular place on Earth and that of Greenwich, England, expressed in degrees or time.

Loss of Signal - The inability to receive a satellite signal because the satellite's orbital path has taken it below the antenna's horizon.

Lower Scene Corners - The corners associated with the leading edge (last scan) of a scene. For descending path scenes, the lower left corner corresponds to the southwest corner of a scene and the lower right corner corresponds to the southeast corner of a scene. For ascending path scenes, the lower left corner corresponds to the northeast corner of a scene and the lower right corner corresponds to the northwest corner of a scene. These mappings hold for the band file geolocation fields and the metadata file.

LPS (output) Files - The generic term used to denote the grouping of Level 0R, browse, and metadata files for a single subinterval. L0R files contain image data, cal data, PCD, and MSCD. Multi-band browse scenes file and metadata file contained in the LPS Output File Set.