This one-month WAC global mosaic was created by mosaicking 2757 nadir-pointing 
WAC images acquired during orbits 13913 through 14328 (6 July 2012 through 
9 August 2012) into a single global image with seamless lighting. The orbit 
tracks progress across the Moon from 360 degrees E to 0 degrees E over the 
course of the month of imaging, with beta angles (the angle between the orbital 
plane and a vector to the Sun) going from -72.8 degrees to -39.3 degrees. Some 
gores may be present due to spacecraft slews for observations by other 
instruments. This mosaic uses the 643 nm band of the WAC. It uses a simple 
cylindrical map projection from 0 to 360 degrees longitude and -90 to 90 
degrees latitude. 

Each image was projected onto the GLD100 (WAC derived 100m/pixel DTM), with 
accurate positioning of each WAC image ensured using ephemeris provided by the 
LOLA and GRAIL team and an improved camera geometry model [1]. All images were 
corrected to a common photometric geometry using a Hapke model [2]. To minimize 
lighting discontinuities near the poles, the images were mosaicked on a per-
pixel basis based on incidence angle (angle between the Sun and the zenith): 
for each pixel in the output, the data was selected from the image with the 
lowest incidence angle at that location.

A note on timing: To get complete coverage at the poles, the source image list 
extends slightly beyond the nominal ~28 days for the orbit track to cover the 
entire Moon.  At the equator, the first and last images with visible data will 
be about 40 orbits (~3 days) after or before the listed start and end times, 
respectively (roughly orbits 13953-14288).


## Image Selection Details ##

Color and monochrome WAC images with:
- data_quality_id < 16, 
- exposure time <= 0.1 seconds
- incidence angle < 95 degrees (or image center within 5 degrees of a pole)
- off-nadir slew angle < 5 degrees
- and orbit between 13913 and 14328, inclusive.

A complete image list can be downloaded separately.


## Naming Scheme and Additional Files ##

The naming scheme for this product is WAC_ORBITS_XXXXX_YYYYY, where XXXXX is the 
first orbit number from which images were used, and YYYYY is the last orbit.

A low-resolution 8-bit browse product in PNG format for this product is 
available at:
http://pds.lroc.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/WAC_ORBITS/13913_14328/WAC_ORBITS_13913_14328.BROWSE.PNG

A full-resolution GeoTIFF version of this product is available at:
http://pds.lroc.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/WAC_ORBITS/13913_14328/WAC_ORBITS_13913_14328.TIF


## References ##

For more information on LROC Reduced Data Records (RDRs), please refer to the
Software Interface Specification (SIS):
http://pds.lroc.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/DOCUMENT/RDRSIS.PDF

[1] Speyerer et al. 2014, Pre-flight and On-orbit Geometric Calibration of the 
    Lunar Reconnaissance Orbiter Camera.
    http://link.springer.com/article/10.1007%2Fs11214-014-0073-3
    
[2] Sato et al. 2014, Resolved Hapke parameter maps of the Moon.
    http://onlinelibrary.wiley.com/doi/10.1002/2013JE004580/abstract