Evapotranspiration
Measurement Instruments
Measurement Definition: The vaporisation of water through direct evaporation from wet surfaces plus the release of water vapour by plants through leaf pores. In remote sensing, evapotranspiration can be estimated using land surface temperature measurements.
| Instrument | Status/
Accuracy | Instrument Description | Measurement Technology | Timeline |
| TIRS | Operational | Measures longwave thermal infrared surface emittance, land cover state, and change. Used as multipurpose imagery for land applications. | n/a |  |
| TIRS-2 | Operational | Measures longwave thermal infrared surface emittance, land cover state, and change. Used as multipurpose imagery for land applications. TIRS-2 will adhere to the Landsat 8 TIRS instrument performance specifications but will be built to NASA Class-B instrument standards (including a 5-year design life). | n/a | |