KPLO ShadowCam Derived Data - CMOS (Controlled Mosaic)

CMOS – Controlled Mosaic

PDS4 Bundle: urn:nasa:pds:kplo-shadowcamDOI: 10.17189/y89z-kt98

This controlled mosaic is composed of ShadowCam images typically acquired on sequential orbits, either on a single day or across a short range of days. The images are calibrated and map-projected using spacecraft position data. In these images, shadowed areas are visible if lit by light reflected from nearby surroundings, while sunlit areas are saturated. A control network is generated to tie the images to the most accurate ground truth available and a bundle adjustment is performed to minimize pointing errors and improve image alignment. The images are then map-projected and mosaicked together into an almost seamless mosaic of the region.

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

Bundleout.txt - The output text file from the USGS ISIS 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 2000 meters 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, the Sigma0 value have been included in the readme file. Sigma0 value 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.

To improve horizontal alignment to the best available LOLA LDEM, an x and y shift have been applied to the mosaic. This shift was applied to the UpperLeftCornerX and UpperLeftCornerY values after bundle adjustment. The overall horizontal offsets are anticipated to be within 10 m from the listed ground source LOLA LDEM. The listed coordinate values in the Bundleout and Residual Plots were generated before this shift value was applied.

In addition to the x and y shift, the final mosaic is trimmed to the target site using the USGS ISIS maptrim tool. Every ShadowCam controlled mosaic of the same target site is trimmed to the same bounds, however each mosaic of a target may have differing extents due to varying image coverage in each mosaic.

ShadowCam CMOS data and related products have the following file names:

shadowcam_Tmosaic_feature##_AyyyBzzz_ssss_tttt<_sup>.ext

where:

shadowcam = a ShadowCam product

T = type of mosaic

u for uncontrolled mosaics

c for controlled mosaics

collar for collar mosaics

feature = the feature name, or an abridged PSR ID in the following format: (WPlat-long-), where lat is the PSR ID latitude to the nearest tenth of a degree, long is the longitude to the nearest tenth of a degree, and WP is the lunar pole (NP for North Pole and SP for South Pole)

## = incremental index number for distinguishing multiple mosaics of the same feature or PSR ID (starts at 01 for that mosaic type)

A = projection type

e for equirectangular,

p for polar stereographic

o for orthographic

yyy = center latitude to the nearest tenth 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 ShadowCam controlled mosaics is 360 positive east.

ssss = local polar 'season'. Summer is defined as above 1.0 sub-solar latitude for the northern hemisphere, and below -1.0 sub-solar latitude for the southern hemisphere. Winter is the same definition as summer, but the hemispheres are switched. Spring occurs between the end of winter and start of summer, and fall occurs between the end of summer and start of winter.

tttt = local lunar time of day relative to the center longitude of the mosaic. The local time of other locations within the mosaic may vary widely due to the rapidly changing longitude near the poles. 6 AM is sunrise, 6 PM is sunset, from 6 PM to 6 AM is night, and from 6 AM to 6 PM is daytime. Calculated using the difference between center longitude and sub-solar longitude. The time is rounded to the nearest hour, and converted from the 24-hour clock (00-23) to the 12-hour clock (12am - 11pm).

_sup = indicates the supplemental product

_5m and _20m indicate the pixel scale in meters, used only for supplementary lower resolution products.

_cog indicates COG - pyramidal product files

_bundleout is the bundle-adjustment output

_cnet contains the USGS ISIS-formatted control network

_residuals is the residuals plot

_binned_residuals is the binned residuals plot

_images indicates the list of images names used in this mosaic

_readme indicates the readme file

ext = file extension for associated products

cub = ISIS cube files

tif = tif image files

txt = text files

pvl = a metadata text file that is written in Parameter Value Language (PVL)

xml= PDS4 XML labels

In ODE, ShadowCam CMOS data products have the following product IDs:

shadowcam_cmosaic_feature##_AyyyBzzz_ssss_tttt<_sup>

More information about the ShadowCam CMOS data products can be found in the following documents:

Wagner, R.V., et al. Cartographic Accuracy of ShadowCam Images, 2024 LPSC LV, Abs. #2357.https://www.hou.usra.edu/meetings/lpsc2024/pdf/2357.pdf.
LROC PSR Atlas: https://lroc.im-ldi.com/atlases/psr.
Manheim, M.R., Henriksen, R.V., Wagner, C.H., Michaud, and the ShadowCam Team,., ShadowCam Digital Terrain Models Of Permanently Shadowed Regions, 2024 LPSC LV, Abs. #1294.
Henriksen M.R., Manheim M.R., Grieser S.A., Carr N.F., Brown H.M., Collins1 W.M., Wagner RV., and Robinson M.S., ShadowCam Derived Mosaics, Digital Terrain Models, And Other Products, 2025 LPSC LVI, Abs. #2571.
Grieser, S. A., Henriksen, M. R., Wagner, R. V., Mahanti, P., Manheim, M. R., & Robinson, M. S. (2024), Investigation of Lunar Polar Regions Using ShadowCam Mosaics. In 45th Committee on Space Research Scientific Assembly, Busan, South Korea, 13-21 July 2024 (Abstract B3.1-0010-24). https://app.cospar-assembly.org/2024/browser/presentation/35177.