Landsat 8: A General Introduction

General Information

NASA in collaboration with the U.S. Geological Survey (USGS) developed and launched Landsat 8 on February 11, 2013, from Vandenberg Air Force Base, California, on an Atlas-V 401 rocket. The design, construction, launch, and on-orbit calibration phases were led by NASA. The satellite then was called the Landsat Data Continuity Mission (LDCM). It was on May 30, 2013 when the USGS took over routine operations and the satellite became Landsat 8. Ever since the USGS has been leading post-launch calibration activities, satellite operations, data product generation, and data archiving at the Earth Resources Observation and Science (EROS) center.

Landsat Timeline. (Image Source: NASA Website)

At an altitude of 705 km (438 mi), inclined at 98.2 degrees, the Landsat 8 satellite is scheduled to circle the Earth every 99 minutes repeating this cycle in every 16-days with an equatorial crossing time: 10:00 a.m. +/- 15 minutes. The orbit is called a sun-synchronous, near-polar orbit.

Till date, Landsat 8 has acquired nearly 2 million scenes (740 scenes per 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 scene size is 185 km x 180 km (114 mi x 112 mi). Data products are available to download from EarthExplorer, GloVis, and the LandsatLook Viewer.

Landsat 8 satellite is a giant body weighing 2,071 kg (4,566 lbs); 3m long (length) and 2.4m wide (diamneter). It carries 3.14 terabit solid-state data recorder which is powered by a single 9 x 0.4 meter solar array and one 125 Ampere-Hour (AHr), Nickel-Hydrogen (NiH2) battery.

Sensors

The Landsat 8 satellite carries two sensors—the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). These two sensors provide seasonal coverage of the global landmass at a spatial resolution of 30 meters (visible, NIR, SWIR); 100 meters (thermal); and 15 meters (panchromatic).

The Operational Land Imager (OLI) was built by Ball Aerospace & Technologies Corporation and captures 9 spectral bands named as Band 1, Band2, …., and Band 9. These bands have improved radiometic precision, improved overall signal to noise ratio, and improved signal to noise performance.

  • These 9 bands are:
    • Band 1 Visible (0.43 – 0.45 µm) 30 m
    • Band 2 Visible (0.450 – 0.51 µm) 30 m
    • Band 3 Visible (0.53 – 0.59 µm) 30 m
    • Band 4 Red (0.64 – 0.67 µm) 30 m
    • Band 5 Near-Infrared (0.85 – 0.88 µm) 30 m
    • Band 6 SWIR 1(1.57 – 1.65 µm) 30 m
    • Band 7 SWIR 2 (2.11 – 2.29 µm) 30 m
    • Band 8 Panchromatic (PAN) (0.50 – 0.68 µm) 15 m
    • Band 9 Cirrus (1.36 – 1.38 µm) 30 m

Thermal Infrared Sensor (TIRS) was built by NASA Goddard Space Flight Center and has 2 spectral bands.

  • These 2 bands are:
    • Band 10 TIRS 1 (10.6 – 11.19 µm) 100 m
    • Band 11 TIRS 2 (11.5 – 12.51 µm) 100 m
The Evolution of Landsat 8 from Landsat 7. (Image Source: NASA Website)

Use of Landsat 8 images

Landsat 8 images have a temporal resolution of 16 days and spatial resolution of 30m. Because of the high temporal and spatial resolution of Landsat 8 images, these images are widely used in various researches and applications including land cover mapping, weather predictions, large forest fires mapping, coastal applications, ocean applications, hazard assessment, natural resource management, and more. The salient features of Landsat 8 include its Data Continuity, Global Survey Mission, Free Standard Data Products, Radiometric and Geometric Calibration and Immediate Delivery. Products available for download immediately; higher-level products available for download within 72 hours.


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