Abstract
We describe the first results of a program to extend the Landolt calibration standards to at least V=19 mag and to calibrate fields separated from the celestial equator. This program is one of several coordinated efforts to find faint type AV and KIII stars suitable for the mid-IR calibration of the 10~m Gran Telescopio CANARIAS. We have obtained 34~712 measurements of 373 stars in 26 quasar fields between declinations -30o and +70o, calculating magnitudes with high precision in the visible and near infrared (UBVRIJHK). The next stages will be to: 1) increase the number of fields covered, 2) take additional observations of poorly covered fields, 3) use our existing database to extend photometry of Selected Areas to include many stars not previously measured by Landolt, and 4) spectral type all candidate KIII and AV stars in the sample. We conclude that both samples (ours and that of Landolt) are increasingly dominated by local dwarfs at faint magnitudes.
