Remote sensing techniques in the exploration for petroleum have not moved from the small-scale, limited study-area, experimental state to full-scale, large-area, operational status. Remote sensing techniques will have come to maturity when total basin surveys for known and potential hydrocarbon anomalies are commonplace. As with much of petroleum exploration, remote sensing is primarily an indirect approach limited to the development of drillable petroleum prospects. The techniques include spectroscopic analysis, which offers the potential for airborne compositional analysis. Research toward the latter objective is still in early phases.
The most commonly used wavelengths are the visible part of the spectrum (0.3–0.7 μ), infrared film emulsions (0.3–0.9 μ), and thermal infrared (8–14 μ). Equipment and materials covering these spectral bands are the best developed and the most widely available.
Exploration in areas of consistently poor illumination because of meteorologic conditions will bring about increased use of the longer wavelength (microwave) equipment. Cloud penetration is a function of wavelength; passive microwave radiometers, side looking radar, and scatterometers possess this capability. Currently, airborne microwave instrumentation is not widely available, but indications are that it will come into wider use.
Service companies prepared to perform multisensor data collecting on a global scale are now operational. They offer, on a contract basis, sophisticated equipment in advanced aircraft, with or without interpretation packages. In addition to petroleum companies, their clientele includes mining companies, widely diversified agricultural interests, and domestic and foreign government agencies.