Landsat 8 Sensors

Landsat 8 launched in February will orbit the Earth fourteen times a day, following the same sequence of ground tracks as Landsat 4, 5 and 7. This allows data to be produced in the same WRS-2 path and row grid system, but collecting 150 more scenes per day than Landsat 7. This greatly increases the possibility of obtaining cloud-free satellite imagery. Although it has been built around a design life of 5 years, it was launched with enough fuel to keep it in orbit and operational for over 10 years. The Landsat satellite has 2 main imaging systems on board. The Thermal Infrared Sensor (TIRS)  and the Operational Land Imager (OLI).

The failure of the Scan-Line Corrector on Landsat 7 has driven the change from a whiskbroom to a pushbroom sensor for the OLI (image 1)on Landsat8. This brings it into line with most other modern satellite systems. Besides this major design change, the other specifications of the OLI are very similar to the Landsat TM and ETM+ sensors.

Imagery will be collected at a resolution of 30m for multispectral data and 15m for panchromatic data with a swath width of 185km. It will include all spectral bands used by Landsat TM and ETM+ along with two extra bands. One is a shorter wavelength blue band designed for aerosol remote sensing and monitoring coastal water quality. The other is a SWIR band designed for monitoring cirrus clouds.

The TIRS instrument (image 2) has also remained similar to its predecessors on Landsat TM and ETM+. The only upgrade being that now the single thermal band is split in two providing measurements at a spatial resolution of 100m.

Image1: The OLI Instrument:  To help calibrate the system the left hand opening will be aligned with the Earth and the right with the Sun.

Image1: The OLI Instrument:
To help calibrate the system the left hand opening will be aligned with the Earth and the right with the Sun.

 

Image2: Landsat 8 TIRS:   (Thermal Infrared Sensor) Instrument. The second of Landsat 8's two sensors.

Image2: Landsat 8 TIRS:

(Thermal Infrared Sensor) Instrument. The second of Landsat 8’s two sensors.

Image 3:  Landsat 8 at Orbital Science Corp.

Image 3:
Landsat 8 at Orbital Science Corp.

Image 4:  Landsat 8 Imagery is taken at different wavelengths and then combined to give the final image. Different terrain features can be seen based on the combination of the different colour layers.

Image 4:
Landsat 8 Imagery is taken at different wavelengths and then combined to give the final image. Different terrain features can be seen based on the combination of the different colour layers.