The two Narrow Angle Cameras (NACs) provide high-resolution (0.5 to 2.0 m/pixel) panchromatic images over a combined 5 km swath. While not designed to image within the Permanently Shadowed Regions (PSR) near the lunar poles, the LROC NACs can obtain useful images with long exposure observations of PSRs at time of maximum secondary illumination. The increased exposure time (20x to 80x) leads to pixel smear and elongated pixels in the along track direction, and thus reduced image resolution compared to typical NAC images (10-40 m/pixel vs. 0.5-2 m/pixel). This may also result in bright saturated pixels outside the PSR. For more information about PSRs and PSR products, refer to [1] or the PSR Atlas. NAC images acquired on consecutive orbits, or occasionally over non-consecutive orbits under very similar lighting conditions (e.g. less than 5 degrees 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 using the GLD100 (WAC derived 100 m/pixel DTM) and LOLA derived crossover corrected ephemeris and mosaicked together into an almost seamless mosaic of the region. A manual linear stretch is performed on images for the final mosaic and it is cropped to the PSR region using a PSR boundary shapefile to create an additional mosaic product. The PSR boundary shapefile is derived from PSR maps modeled from LOLA [2]. This shapefile can be found with the polar PSR mosaic, linked below. To determine which PSR ID corresponds with which PSR, refer to the downloadable PSR map.

When citing this product, use the following reference: Cisneros, E., Awumah, A., Brown, H. M., Martin, A. C., Paris, K. N., Povilaitis, R. Z., Boyd, A. K., & Robinson, M. S. (2017, March). Lunar Reconnaissance Orbiter Camera Permanently Shadowed Region Imaging - Atlas and Controlled Mosaics. In Lunar and Planetary Science Conference (Vol. 48, Abstract #2469).

For more information about this and other RDRs, see the RDR Software Interface Specification (SIS) at

PSR Atlas
North PSR Pole Mosaic

[1] Cisneros, E., et al. "Lunar Reconnaissance Orbiter Camera Permanently Shadowed Region Imaging - Atlas and Controlled Mosaics." Lunar and Planetary Science Conference. Vol. 48. 2017. Abstract #2469.

[2] Mazarico, E., et al. "Illumination conditions of the lunar polar regions using LOLA topography." Icarus 211.2 (2011): 1066-1081.


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.

For PSR mosaics that have been stretched to visualize the area inside the PSR, the coordinate string (AyyyBzzzz) has been replaced with the word 'STRETCHED'.

Examples: NAC_ROI_PSRAMUNDLOA_P834S0854.IMG is a NAC ROI of the PSRs in Amundsen crater with low-Sun. A indicates it's the first low-Sun mosaic of the Amundsen crater PSR produced. This mosaic is centered at latitude=83.4S, longitude=85.4E and is in Polar Stereographic projection.


Site Name Permanently Shadowed Regions in Peary
PSR IDs NP_879680_0297220
Center Lat 87.6
Center Lon 45.4
Pixel Scale 14.00 m/px
Image Start Time (UTC) 2013-03-27 11:45:13.535+00
Image Stop Time (UTC) 2014-01-21 19:46:28.249+00
# Images 3
Incidence Low Sun
Minimum Latitude 86.92
Maximum Latitude 88.32
Minimum Longitude 11.87
Maximum Longitude 78.84

Link to browse PNG

Images used, in order of layering from front to back:
Image ID Center Lat Center Lon Incidence Pixel Scale
M1144972781R 87.87 36.71 89° 18.27 m/px
M1119023956L 87.83 23.59 87° 18.77 m/px
M1144944359R 87.84 41.08 89° 5.16 m/px

Permanently Shadowed Regions in Peary low-Sun controlled NAC mosaic (A)

Cropped and stretched mosaic (14.00 m/px) (click for more information)

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