DATASET_DESCRIPTION |
Data Set Overview
=================
A Surface Normal (UVW) file contains 3 bands of 32-bit floating
point numbers in the Band Sequential order. Alternatively, U, V and
W may be stored in separate single-band files as a U Component RDR,
V Component RDR and W Component RDR, respectively. The single
component RDRs are implicitly the same as the UVW file.
Processing
==========
The pixels in a UVW image correspond to the pixels in an XYZ file,
with the same image geometry. However, the pixels are interpreted
as a unit vector representing the normal to the surface at the point
represented by the pixel. U contains the X component of the vector,
V the Y component, and W the Z component. The vector is defined to
point out of the surface (e.g. upwards for a flat ground). The unit
vector can be referenced to any of the MER coordinate systems
(specified by the DERIVED_IMAGE_PARAMS Group in the PDS label).
Most UVW images will contain holes, or pixels for which no UVW
value exists. These are caused by many factors such as differences
in overlap, correlation failures, and insufficient neighbors to
compute a surface normal. Holes are indicated by U, V, and W all
having the same specific value. Unlike XYZ, (0,0,0) is an invalid
value for a UVW file, since they are defined to be unit vectors. Thus
there is no issue with the MISSING_CONSTANT as there is with XYZ,
where (0.0,0.0,0.0) is valid.
Data
====
Surface Normal (UVW) RDR: 3 bands, Float data type, DualPDS/VICAR
(OPGS) binary file.
Surface Normal U-component RDR: 1 band, Float data type, PDS (SOAS)
or dual PDS/VICAR (OPGS) binary file.
Surface Normal V-component RDR: 1 band, Float data type, PDS (SOAS)
or dual PDS/VICAR (OPGS) binary file.
Surface Normal W-component RDR: 1 band, Float data type, PDS (SOAS)
or dual PDS/VICAR (OPGS) binary file.
The RDR data product is comprised of radiometrically decalibrated
and/or camera model corrected and/or geometrically altered versions
of the raw camera data, in both single and multi-frame (mosaic)
form. Most RDR data products will have PDS labels, or if generated
by MIPL (OPGS), dual PDS/VICAR labels. Non-labeled RDRs include the
Terrain products (Mesh and Wedge).
The following is a list of the types of Surface Normal RDRs along
with the Product Type Identifier, which is an element in the formal
RDR file name:
Data Product Linearized Non-Linearized
------------ ---------- --------------
UVW (XYZ) Surface Normal RDR UVW UVL
UVW (XYZ) Surface Normal RDR (Thumbnail) UVT UVN
U (X) Surface Normal RDR UUU UUL
U (X) Surface Normal RDR (Thumbnail) UUT UUN
V (Y) Surface Normal RDR VVV VVL
V (Y) Surface Normal RDR (Thumbnail) VVT VVN
W (Z) Surface Normal RDR WWW WWL
W (Z) Surface Normal RDR (Thumbnail) WWT WWN
Software
========
The MIPL Mars Program Suite was used to generate these RDRs.
Media/Format
============
The data set will initially be delivered and kept online. Upon
Mission completion, the Hazcam Operations RDRs will be delivered
to PDS on DVD.
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