Table 1.

General methods to measure ground temperatures.

Ground temperature measurement method	Advantages	Drawbacks
Contact sensor	- Technically simple. - Gives the real kinematic temperature.	- Very localized measurement. - Gives the temperature where there sensor is buried, which may differ from the skin temperature (layer of dust). - Mission technical restrictions.
Contactless sensor	- Gives the skin temperature, i.e., the temperature of the first microns of the surface. - Possible to measure over a large area, to avoid local effects in the temperature. - Possible to measure the temperatures of different points moving the sensor.	- Technically more complex. - Gives the brightness temperature of the surface. - Needs a correction from atmospheric effects. - The emissivity of the surface and the atmospheric emission are needed in order to give the kinematic temperature. - Atmosphere absorbance (transmission windows).
Contactless sensor with color pyrometry	The same as the standard contactless, technique but also: - Gives the real kinematic temperature.	- Needs at least two measuring bands and a very good estimation of atmospheric effects, so more complex than the standard contacless technique.