S.D. Maley writes of an interesting and somewhat surprising NASA program trying to fill in observation gaps where satellites are getting cloud cover wrong:
NASA is in the process  of checking two satellites  against ground observer reports. Student groups seem to be the primary focus, but adults can participate via:
The Database can be searched , and some of the ground observer reports have comparisons with what the satellite passing over was seeing. For example, one where the satellite saw 3 levels, but ground observer only noticed high level clouds:
I have taken a few digital photos while doing ground observations for SCOOL Rover. When the sky overhead appeared to be clear, the satellite sometimes picked up 2 or 3 levels of “clouds”. As the satellite listed Opacity as Transparent, how would a ground observer be able to detect them?
Nonetheless, the Database might be a resource for helping train ground spotters about cloud classification, … unless the CERES sensors are so good that ground spotters will only be useful to fill in the gaps between satellite overpasses, or for fast-moving weather events.
 Database search goes back into 2008, but only a scattering of reports have both ground and satellite, even though the satellites were launched in 1999 and 2002. The reports by user Cloudie for Mar2008 suggest how hard it is for a ground observer to discern cloud altitude (though one confounding factor is that ground observer reports AGL(AboveGroundLevel), and satellites are likely showing MSL (MeanSeaLevel)).
 Aqua and Terra, polar-orbiting satellites carrying CERES (Cloud and the Earth’s Radiant Energy System) sensors.