The Enhanced Thematic Mapper Plus (ETM+)
The Enhanced Thematic Mapper Plus (ETM+) instrument is a fixed “whisk-broom”, eight-band, multispectral scanning radiometer capable of providing high-resolution imaging information of the Earth’s surface. It detects spectrally-filtered radiation in VNIR, SWIR, LWIR and panchromatic bands from the sun-lit Earth in a 183 km wide swath when orbiting at an altitude of 705 km.
The primary new features on Landsat 7 are a panchromatic band with 15 m spatial resolution, an on-board full aperture solar calibrator, 5% absolute radiometric calibration and a thermal IR channel with a four-fold improvement in spatial resolution over TM.
Landsat 7 collects data in accordance with the World Wide Reference System 2, which has catalogued the world’s land mass into 57,784 scenes, each 183 km wide by 170 km long. The ETM+ produces approximately 3.8 gigabits of data for each scene. An ETM+ scene has an Instantaneous Field Of View (IFOV) of 30 meters x 30 meters in bands 1-5 and 7 while band 6 has an IFOV of 60 meters x 60 meters on the ground and the band 8 an IFOV of 15 meters. Please visit the L7 Science Data Users Handbook for a detailed description of ETM+ spatial characteristics.
ETM+ Technical Specifications
- Sensor type: opto-mechanical
- Spatial Resolution: 30 m (60 m - thermal, 15-m pan)
- Spectral Range: 0.45 - 12.5 µm
- Number of Bands: 8
- Temporal Resolution: 16 days
- Image Size: 183 km X 170 km
- Swath: 183 km
- Programmable: yes