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The color map was adapted from the Hapke Normalized WAC Mosaic, a composite built by the camera team from over 100,000 WAC (Wide Angle Camera) images. The readme file provides a technical summary of how the mosaic was constructed along with references to more detailed publications. A less formal introduction to the process is in this LROC blog post.
For the color map here, the visualizer modified and combined three of the seven wavelength bands of the LROC color data to more closely match what the human eye sees. The red channel contains the 643 nm band, while green and blue were created from different linear combinations of the 566 and 415 nm bands to more nearly center them on 532 nm (green) and 472 nm (blue). A gamma of 2.8 was applied (the LROC data is linear), and the channels were multiplied by (0.935, 1.005, 1.04) to balance the color. The intensity range (0.16, 0.4) was mapped into the full (0, 255) 8-bit range per channel. Small data dropouts near the top and bottom were inpainted using Photoshop's content-aware spot healing brush.
The source data covers the lunar globe from 70°N to 70°S. Because the Moon's axial and orbital tilts are both small, many areas outside these latitudes remain shrouded in shadow, even after thousands of passes by LRO's camera, so they are left out of the LROC mosaic. For this color map, the missing latitudes were filled in with a combination of monochromatic LROC data and an albedo map (LDAM) from LRO's laser altimeter. When rendered with realistic shadows, these parts of the map aren't particularly visible, and while they comprise more than 20% of the map's pixels, they represent only 6% of the Moon's surface.
https://svs.gsfc.nasa.gov/4720?fbclid=I ... 3AXTDcnaD8
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