The two Narrow Angle Cameras (NACs) provide high-resolution (0.5 to 2.0 m/pixel) panchromatic images over a combined 5 km swath. NAC images acquired on consecutive orbits, or occasionally over non-consecutive orbits under very similar lighting conditions (e.g. less than 5° difference in incidence angle and the same sun direction), can be combined to create controlled mosaics. A control network is generated to tie the images to the most accurate ground truth available and a bundle adjustment is performed to correct for pointing errors and image alignment. The images are then map-projected and mosaicked together into an almost seamless mosaic of the region. The digital terrain model used for the radius source and for map-projection are listed below.

There are a few files included to assist in evaluating the controlled mosaic. These include:

Bundleout.txt - The output text file from the ISIS3 jigsaw tool summarizing the results of bundle-adjusting the control network. For more information, see: https://isis.astrogeology.usgs.gov/Application/presentation/Tabbed/jigsaw/jigsaw.html

Residual Plot - A plot of every residual overplotted onto a 20 m/px version of the mosaic. This is useful for local inspection of residuals (in pixels), which ideally should be zero, but we consider residuals less than one acceptable.

Binned Residual Plot - A plot with the residuals (in pixels) binned by 0.05 degrees of latitude and longitude. It can be used to determine if there are any trends in the residuals over the entire mosaic. Ideally residuals should be very close to zero and there should be no trends in the directions.

In addition to the provided files, we have included the Sigma0 value below, which is the standard deviation of unit weight and a summary number for the bundle-adjustment performed by jigsaw. Ideally, Sigma0 should be less than one.

When citing this product, use the following reference:

Klem, S. M., Henriksen, M. R., Stopar, J., Boyd, A., & Robinson, M. S. (2014). Controlled LROC Narrow Angle Camera High Resolution Mosaics. In Lunar and Planetary Science Conference (Vol. 45, abstract #2885). https://www.hou.usra.edu/meetings/lpsc2014/pdf/2885.pdf

PDS PRODUCT NAMING CONVENTION

The PRODUCT_ID naming convention for LROC NAC ROIs is:

NAC_ROI_xxxxxxxxSSv_AyyyBzzzz[_##M].IMG where

• NAC_ROI = indicating it's a NAC ROI product
• xxxxxxx = words specifying the sitename (8 characters)
• SS = LO for low Sun angle or HI for high Sun angle
• v = incremental character for distinguishing multiple mosaics with similar lighting of the same region. Letters are used for individual mosaics and numbers are used for composite mosaics composed of mulitiple controlled mosaics.
• A = projection type (E for equirectangular, P for polar stereographic)
• yyy = center latitude to the nearest 10th of a degree
• B = N for northern hemisphere, S for southern hemisphere
• zzzz = center longitude to the nearest tenth of a degree. The longitude domain for all NAC DTMs is 360 positive east.
• [_##M] = indicates the pixel scale in meters; used only for supplementary lower resolution products.

Example: NAC_ROI_APOLLO15LOC_E252N0018.IMG is a NAC ROI of the Apollo 15 landing site with low-Sun. C indicates it's the third low-Sun mosaic of the Apollo 15 landing site produced. This mosaic is centered at latitude=25.2N, longitude=1.8E and is in equirectangular projection.

RDR Name	NAC_ROI_PETAVIUBLOB_E212S0562
Site Name	Petavius B UV Anomaly
Center Lat	-21.2
Center Lon	56.2
Pixel Scale	0.80 m/px
Image Start Time (UTC)	2013-05-14 23:25:31.707+00
Image Stop Time (UTC)	2013-05-15 03:23:00.814+00
# Images	6
Incidence	Low Sun
Minimum Latitude	-21.83
Maximum Latitude	-20.50
Minimum Longitude	55.81
Maximum Longitude	56.60
Sigma0	0.21
Map Projection DTM	GLD100 with LOLA 30M POLE [SCHOLTENETAL2012]
Radius Source	GLD100 with LOLA 30M POLE [SCHOLTENETAL2012]

Images used, in order of layering from front to back:

Image ID	Center Lat	Center Lon	Incidence	Pixel Scale
M1123213199R	-21.17	56.37	68°	0.80 m/px
M1123213199L	-21.17	56.51	68°	0.79 m/px
M1123220311R	-21.16	56.14	67°	0.74 m/px
M1123220311L	-21.16	56.26	67°	0.74 m/px
M1123227423R	-21.16	55.90	66°	0.76 m/px
M1123227423L	-21.16	56.03	66°	0.77 m/px

Link to browse PNG
NAC_ROI_PETAVIUBLOB

Petavius B UV Anomaly low-Sun controlled NAC mosaic (B)