The Lunar Orbiter images on this website were all digitally scanned at 400 dpi at the Lunar and Planetary Institute in Houston. Whole images were too large to be scanned at once and were broken up into four sections, A-D. A is the upper right quadrant, B the lower right, C the lower left and D the upper left, with some overlap between each. If no letter follows the image number, only a portion of the image was scanned. Images were selected from the Lunar Orbiter collection based on the presence of craters with boulders, thus they over-represent the proportion of blocky craters.
Data about each lunar orbiter image can be found in Anderson and Miller (1971). From this resource we obtained information about the side length, altitude and emission angle of the images we scanned. To calculate the resolution of each image we followed several steps. We first calculated the resolution of images with an emission angle of less than 10° by dividing the side length of each image by the number of pixels. We then calculated the distance to the surface by dividing the altitude by the cosine of the emission angle. The resolution of low-emission angle images was plotted against their distance to the surface. From this we obtained the best-fit equation
corrected resolution = -0.0023272 + 0.014376 * distance to surface
and applied it to the remaining images to get the corrected resolution. For examples of the use of these data see Robinson et al. (2002) and Wilcox et al. (2002a, 2002b, 2005).
These scans were acquired by B.B. Wilcox as part of her Undergraduate Honors project at Northwestern University. For further information contact firstname.lastname@example.org.
Many thanks to Mary Ann Hager (Lunar and Planetary Institute) and Paul Spudis (formerly Lunar and Planetary Institute, now Johns Hopkins Univertsity Applied Physics Lab) for all of their help.
Hansen, T.P. (1970), Guide to Lunar Orbiter Photographs, NASA SP-242, 125 p.
Robinson, M.S., P.C. Thomas, J. Veverka, B.B. Wilcox (2002), Geology of 433 Eros, Meteoritics and Planetary Science, 37, 1651-1684.
Wilcox, B.B., M.S. Robinson, P.C. Thomas, B.R. Hawke (2005), Constraints on the depth and variability of the lunar regolith, Meteoritics and Planetary Science, 40, 695-710.
Wilcox, B.B., M.S. Robinson, P.C. Thomas (2002a), Regolith thickness, distribution, and processes examined at sub-meter resolution (abstract). Workshop on the Moon Beyond 2002 #3048, Lunar and Planetary Institute, Houston, TX.
Wilcox, B.B., M.S. Robinson, P.C. Thomas (2002b), Lunar Boulders Seen at Very High Resolution: Implications for 433 Eros (abstract). Lunar and Planetary Sciences Conference XXXIII, #1637, Lunar and Planetary Institute, Houston TX.
Space Exploration Resources ~ School of Earth and Space Exploration ~ Arizona State University