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.

Due to the large size of this NAC ROI mosaic, the highest-resolution tiffs and pyramidal tiffs were down-sampled from 1.30 m/px to 2.40 m/px to fit the size constraints of the TIFF format.

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_VSCHROTELO1_E258N3093
Site Name	Vallis Schroteri
Center Lat	25.8
Center Lon	309.3
Pixel Scale	1.30 m/px
Image Start Time (UTC)	2012-06-02 15:22:21+00
Image Stop Time (UTC)	2014-06-22 17:36:07.389+00
# Images	22
Incidence	Low Sun
Minimum Latitude	23.73
Maximum Latitude	27.85
Minimum Longitude	307.04
Maximum Longitude	311.55
Sigma0	0.29
Map Projection DTM	GLD100 with LOLA 30M POLE [SCHOLTENETAL2012]
Radius Source	GLD100 with LOLA 30M POLE [SCHOLTENETAL2012]

This mosaic is a composite mosaic formed from the following NAC ROI controlled mosaic products:

• NAC_ROI_COBRAHD_LOA
• NAC_ROI_VSCHROTELOA
• NAC_ROI_VSCHROTELOB

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

Image ID	Center Lat	Center Lon	Incidence	Pixel Scale
M1108603578R	24.93	310.30	73°	1.36 m/px
M1108603578L	24.94	310.54	72°	1.37 m/px
M1108589284R	24.95	311.14	74°	1.38 m/px
M1108589284L	24.96	311.38	74°	1.38 m/px
M1108596431R	24.94	310.73	73°	1.36 m/px
M1108596431L	24.95	310.96	73°	1.36 m/px
M1123939436R	26.70	308.85	73°	1.34 m/px
M1123939436L	26.70	309.09	73°	1.35 m/px
M1123932324R	26.69	309.30	74°	1.33 m/px
M1123932324L	26.69	309.53	74°	1.33 m/px
M1123925213R	26.69	309.75	74°	1.34 m/px
M1123925213L	26.69	309.99	74°	1.34 m/px
M1158076433R	25.42	308.67	69°	1.24 m/px
M1158076433L	25.41	308.45	69°	1.25 m/px
M1158083552R	25.41	308.25	70°	1.23 m/px
M1158083552L	25.40	308.04	70°	1.23 m/px
M1158090672R	25.39	307.85	70°	1.25 m/px
M1158090672L	25.38	307.63	70°	1.24 m/px
M1158097791R	25.38	307.42	71°	1.29 m/px
M1158097791L	25.37	307.18	71°	1.28 m/px
M193289808L	26.07	310.07	76°	1.39 m/px
M193289808R	26.07	309.82	76°	1.39 m/px

Link to browse PNG
http://lroc.sese.asu.edu/data/LRO-L-LROC-5-RDR-V1.0/LROLRC_2001/EXTRAS/BROWSE/NAC_ROI/VSCHROTELO1/NAC_ROI_VSCHROTELO1_E258N3093.BROWSE.PNG

Vallis Schroteri Composite low-Sun controlled NAC mosaic (Combined mosaic #1)