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(i.e. multispectral scanners)

So what is not absorbed by the object or transmitted through the object is reflected by the object Reflected energy is what most remote sensor records (some also have detectors that record emitted thermal energy)

optical sensors (multispectral scanners) Radar, Lidar

Platform / Sensor(s) Resolution (revisit time) Length of record AVHRR (1km)daily35 years (1979-) MODIS ( m) daily15 years (1999-) Landsat MSS (80m)16 days41 years ( ) Landsat TM/ETM+/OLI (30m) 8-16 days33 years (1982-) SPOT HRV (20m)26 days29 years (1986-) Ikonos (4m)Variable (tasking)15 years (1999-) Quickbird (2.5m)Variable (tasking)13 years (2001-)

Improved temporal resolution (daily or weekly coverage) allows you to produce clear-sky composite imagery and do time-series trend analysis