Nearly 10,000 scenes were acquired by the Operational Land Imager (OLI) and/or Thermal Infrared Sensor (TIRS) sensors after launch (February 11, 2013) through April 10, 2013, when the satellite achieved operational orbit (WRS-2). Landsat 8 data products are consistent with all Landsat standard Level-1 data products, using the specifications described on the Landsat Processing Details page. Data rate: 384 Mbps on X-band frequency 260.92 Mbps on S-band frequency.Direct Downlink with Solid State Recorders (SSR).Weight: 2,071 kg (4,566 lbs) fully loaded with fuel (without instruments).Power provided by a single 9 x 0.4 meter solar array and one 125 Ampere-Hour (AHr), Nickel-Hydrogen (NiH2) battery.Thermal Infrared Sensor (TIRS) - Built by NASA Goddard Space Flight Center Products are scaled to 55,000 grey levels, and can be rescaled to the Top of Atmosphere (TOA) reflectance and/or radiance using radiometric rescaling coefficients provided in the product metadata file (MTL file).
The 12-bit data are scaled to 16-bit integers and delivered in the Level-1 data products. Improved signal to noise performance enables improved characterization of land cover state and condition. OLI captures data with improved radiometic precision over a 12-bit dynamic range, which improves overall signal to noise ratio. This translates into 4096 potential grey levels, compared with only 256 grey levels in Landsat 1-7 8-bit instruments.
Landsat 8 acquires about 740 scenes a day on the Worldwide Reference System-2 (WRS-2) path/row system, with a swath overlap (or sidelap) varying from 7 percent at the equator to a maximum of approximately 85 percent at extreme latitudes. The satellite has a 16-day repeat cycle with an equatorial crossing time: 10:00 a.m. Landsat 8 orbits the the Earth in a sun-synchronous, near-polar orbit, at an altitude of 705 km (438 mi), inclined at 98.2 degrees, and completes one Earth orbit every 99 minutes.
0 kommentar(er)
