Empirically Normalized 7-Color Reflectance of the Moon

 

This empirically normalized Wide Angle Camera (WAC) color mosaic covers area from 60°S to 60°N and 0°E to 360°E; it is composed of seven wavelength bands (321 nm, 360 nm, 415 nm, 566 nm, 604 nm, 643 nm, and 689 nm). The 7-band mosaic was constructed from 137,400 color WAC images acquired from January 21, 2010 to January 31, 2013 over a broad range of lighting and viewing geometries.

Each pixel from the WAC observations were photometrically normalized to a standard geometry of 30° incidence angle, 0° emission angle, and 30° phase angle using an empirically derived photometric function similar to that of Boyd et al., 2012 and local topography provided by the GLD100 (WAC derived 100m/pixel Digital Terrain Model; Scholten et al., 2012). The median of normalized reflectance values (average n=142) for each 1600 m² area were computed and stored in an equal area projection. The final archive products were created by transforming this to a simple cylindrical projection in eight regional tiles that encompass 60° latitude by 90° longitude at 64 pixels/degree (~475 meters/pixel) and 304 pixels/degree (~100 meters/pixel).

Spatial accuracy of each WAC image was ensured using ephemeris provided by the LOLA and GRAIL teams (Mazarico et al., 2012) and an improved geometric camera model (Speyerer et al., 2014).

 

The archived products are available at 64 pixels/degree for all 7-bands and additonally at 304 pixels/degree for the 643 nm band. For the 643 band, additional tiles in polar stereographic projection at 304 pixels/degree are available and contain data from 60°-90° latitude. A 3-band 8-bit/band RGB (R=689 nm, G=415 nm, B=321 nm) mosaic at 64 pixels/degrees is also archived using the same tiling scheme. All tiled product files are named in following manner: WAC_EMP_[wavelength, e.g., 321NM]_[projection, E for equirectangular|P for Polar Stereographic][center latitude x10][N/S][center longitude x10]_[Pixels/Degree].

 

References:

Boyd, A.K., Robinson, M.S., and Sato, H. (2012), Lunar Reconnaissance Orbiter Wide Angle Camera Photometry: An Empirical Solution, In 43^rd Lunar and Planetary Science Conference, Abstract #2795.

Mazarico, E., Rowlands, D.D., Neumann, G.A., Smith, D.E., Torrence, M.H., Lemoine, F.G., Zuber, M.T., (2012), Orbit determination of the Lunar Reconnaissance Orbiter, Journal of Geodesy , Volume 86, Issue 3, pp.193-207, doi:10.1007/s00190-011-0509-4

Scholten, F., J. Oberst, K.-D. Matz, T. Roatsch, M. Wählisch, E.J. Speyerer, M.S. Robinson (2012), GLD100 – the near-global lunar 100 meter raster DTM from LROC WAC stereo image data, Journal of Geophysical Research, 117, doi:10.1029/2011JE003926.

Speyerer, E.J., R.V. Wagner, M.S. Robinson, A. Licht, P.C. Thomas, K. Becker, J. Anderson, S.M. Brylow, D.C. Humm, M. Tschimmel (2014), Pre-flight and On-orbit Geometric Calibration of the Lunar Reconnaissance Orbiter Camera, Space Science Reviews, doi:10.1007/s11214-014-0073-3

For more information on LROC Reduced Data Records (RDRs), please refer to the LROC RDR Software Interface Specification (SIS).

WAC Empirically Normalized Mosaic

3-band color (064 ppd) 321 nm wavelength (064 ppd) 360 nm wavelength (064 ppd) 415 nm wavelength (064 ppd) 566 nm wavelength (064 ppd) 604 nm wavelength (064 ppd) 643 nm wavelength (064 ppd) 689 nm wavelength (064 ppd) 643 nm wavelength (304 ppd)

3-band color (064 ppd)

321 nm wavelength (064 ppd)

360 nm wavelength (064 ppd)

415 nm wavelength (064 ppd)

566 nm wavelength (064 ppd)

604 nm wavelength (064 ppd)

643 nm wavelength (064 ppd)

689 nm wavelength (064 ppd)

643 nm wavelength (304 ppd)