airborne methods  search
NTAVHRR
 AVIRIS
RTgeophysical methods
 geophysical surveys
 photogeology
 remote sensing
 aeromagnetic maps
 magnetic methods
 aircraft
 ground methods
 multispectral scanner
 SAR
 SLAR
 thematic mapper
 total-field methods
 vertical-gradient methods
SNBefore 1978, also search airborne.