Enhanced Thematic Mapper Plus (ETM+)
The Enhanced Thematic Mapper Plus (ETM+) is the main instrument on board Landsat-7 and has been operational since 1999.
ETM+ is an 8-band whiskbroom scanning radiometer consisting of:
- A primary mirror that sweeps side-to-side (across-track) to produce forward and reverse image scans, and
- A Scan Line Corrector (SLC) mirror assembly that sweeps forward-to-back to compensate for the forward motion of the spacecraft during integration time. The motion of these mirrors deviates from an ideal line profile, introducing along- and cross-track geometric distortions that require compensation.
The principal functional differences between the ETM+ and the former TM series are the addition of a 15 m resolution panchromatic band and two 8-bit "gain" ranges. The ETM+ adds a 60 m resolution thermal band, replacing the 120 m band on ETM/TM (band Number 6). ETM+ data therefore cover the visible, Near Infra-Red (NIR), shortwave, and Thermal Infra-Red (TIR) spectral bands of the electromagnetic spectrum.
|Swath Width||185 km|
|Spatial Resolution||15 m PAN|
30 m VNIR/SWIR
60 m TIR
Landsat operated in the SAM (Scan Angle Monitor) Mode for nominal routine operations. On 1 April 2007, Landsat-7 was switched to the 'backup' BUMPER mode to help correct issues associated with the end of an instruments lifetime. More information on this mode-switch is available in the monthly update from April 2002.
|Band No.||Wavelength (µm)|
|8||0.52 - 0.90||PAN|
|1||0.45 - 0.52||(VIS, blue)|
|2||0.53 - 0.61||(VIS, green)|
|3||0.63 - 0.69||(VIS, red)|
|4||0.77 - 0.90||NIR|
|5||1.55 - 1.75||SWIR|
|7||2.08 - 2.35||SWIR|
|6||10.4 - 12.5||TIR|
Through the Online Dissemination server, ESA offers registered users access to the following data collections:
- Landsat-7 ETM+ (Enhanced Thematic Mapper Plus) Geolocated Terrain Corrected Systematic processing (LANDSAT.ETM.GTC): Landsat-7 ETM+ ortho-rectified Level 1T dataset acquired by ESA stations (Europe, including Greenland and West Africa)
- Landsat 7 ETM + European and Mediterranean Countries Cloud Free Collection
Landsat-7 data can be processed using the HEDAVI tool. The HEDAVI (HEritage DAta Visualisation) service enables users to discover a wealth of heritage data from ESA's ERS and Envisat missions, as well as from Landsat-5 and Landsat-7.
Read more about the processor releases for ETM+.
Calibration allows the traceability of satellite sensor data to physical standards, and provides a routine check on instrument performance.
Validation establishes the link between EO measurements from space to derived data products and measurements on the ground, allowing for the verification of the algorithms, and models used to derive parameters and data products.
Calibration Activities and Reports are available for ETM+.
ETM+ Quality Control Reports
ETM+ Quality Control Reports detail the availability of products, any anomalies and the Pick-up Noise issue that affected some products.