Data package for opportunistic constant target matchup study

Opportunistic constant target matching is a new method for satellite
intercalibration.

It is complementary to the traditional simultaneous nadir overpass
(SNO) method because it can provide warm matchups in cases where the
SNO method provides only cold matchups.

A geostationary infrared sensor (SEVIRI) is used to select constant
target matches for two different microwave sensors (NOAA 18 and Metop
A). This is the data package for a publication where we discuss the
main assumptions and limitations of the new method and explore its
statistical properties with a simple Monte Carlo simulation and with
real observations from NOAA 18 and Metop A.