ABSTRACT
Photometry has been used as a technique for optical sensing ever since humans first looked at the horizon. Interpretation of photometric data is of value in obtaining geological or geophysical information from aircraft, earth meteorological or planetary satellites, or planetary landing craft. However, extensive spectral reflectance measurements are necessary to reduce ambiguity in data interpretation. Vast amounts of photometric data are readily obtained from observations of planetary surfaces. Such measurements were made by Krinov [1] on various soils, rocks, and sands and some vegetation. Additional measurements were made by Bauer and Dutton [2] on farmlands and wooded hills of Wisconsin and by Romanova [3] where sand deposits. The data may ultimately be presented graphically or as a picture.
