CLEM UVVIS Global Basemap Mosaic (MDIMG)

MDIMG – UVVIS Global Basemap Mosaic

Instrument: Ultraviolet/Visible Camera

PDS Data Set ID: CLEM1-L-U-5-DIM-BASEMAP-V1.0DOI: 10.17189/1520170

For more information about UVVIS MDIMG products, see the Data Set Catalog File.

The Ultraviolet/Visible camera (UVVIS) Global Basemap Mosaic (MDIMG) is a radiometrically and geometrically controlled, photometrically modeled global mosaicked digital image model compiled using more than 43,000 images from the 750 nm filter observations of the UVVIS. The MDIMG is mapped in Sinusoidal Equal-Area Projection at a resolution of 100 meters per pixel.

The basemap is partitioned into 14 geographic zones. Twelve zones, each 30 degrees wide in longitude and ranging from 70 degrees north to 70 degrees south, make up the mid-latitude regions. The two polar zones cover 360 degrees of longitude from 70 degrees latitude to the pole. The polar regions additionally contain orthographic projection maps centered at the poles. The data set also contains reduced-resolution planetwide coverage at 0.5, 2.5, and 12.5 km/pixel. Backplane data files for emission, incidence, and phase angle values are also present.

The 14 geographic zones are further divided into “tiles”. Each tile covers ~7 degrees of latitude and ~6 degrees of longitude at the equatorial regions to larger longitude coverage at higher latitudes (longitude convergence at the poles allows more longitude coverage of each tile at the higher latitudes with approximately the same file size). Tiles are stored as image files of approximately 2000 pixels on a side. Pixels are 16-bit signed integers.

Processing for the creation of the MDIMG includes radiometric and geometric correction, spectral registration, photometric normalization, and image mosaicking. Radiometric correction applies ‘flat fielding’, dark current subtraction, non-linearity correction, and conversion to radiometric units. Geometric transformations tie each raw image with a ground control network and convert from raw image coordinates to the Sinusoidal Equal-Area projection. Photometric normalization is applied to balance brightness variations due to illumination differences among the images in a mosaic. Images are then mosaicked together to form a global map of continuous image coverage for the entire Moon.

UVVIS MDIMG products have the following file names:

traadooo.IMG

where:

t = data type

B = Clementine Basemap Mosaic

E = Emission angle backplane

I = Incidence angle backplane

P = Phase angle backplane

r = resolution (km/pixel)

I = 0.1

J = 0.15

M = 0.5

Q = 2.5

U = 12.5

aa = 2-digit truncated integer center latitude of image file (00-90)

d = latitude

N = Positive latitude

S = Negative latitude

ooo = 3-digit truncated integer center longitude of image (000-360)

In ODE, MDIMG products have the following product IDs:

TRAADOOO