NASA Technical Reports Server (NTRS) 20080021599: Initial On-Orbit Spatial Resolution Characterization of OrbView-3 Panchromatic Images

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by  NASA Technical Reports Server (NTRS)

Initial On-orbit Spatial Resolution Cha
Panchromatic Images
Slawomir Blonski
Science Systems & Applications, Inc.
John C. Stennis Space Center, MS 39529 81~k~~W~O~1m~#~_T~ACETETU1
Characterization was conducted under the Memorandum of
Understanding among Orbital Sciences Corp., ORBIMAGE,
Inc., and NASA Applied Sciences Directorate.
Acquired five OrbView-3 panchromatic images of the
permanent Stennis Space Center edge targets painted on a
concrete surface. 30
Each image is available at two processing levels: Georaw
and Basic. ' 0 ? , ~ 4 d 4 4 D 1 4 1 I
- Georaw is an intermediate image in which individual Oi.*no.,BSO
pixels are aligned by a nominal shift in the along-scan Ua.lr.2llW~elma0.~TARCET.W
direction to adjust for the staggered layout of the
panchromatic detectors along the focal plane array.
Georaw images are engineering data and are not
delivered to customers.
-The Basic product includes a cubic interpolation to align
the pixels better along the focal plane and to correct for
sensor artifacts, such as smile and attitude smoothing.
-
This product retains satellite geometry no rectification is
performed.
Processing of the characterized images did not include ' o ? , 0 4 . 4 4 0 1 . 1 1
DI.MO.,(UD
image sharpening, which is applied by default to OrbView-3
image products delivered by ORBIMAGE to customers. Pn.letlllO.Llmng..TARCET,Ul
Edge responses were extracted from images of tilted edges
in two directions: along-scan and cross-scan.
Each edge response was approximated with a superposition
of three sigmoidal functions through a nonlinear least-
squares curve-fitting.
Line Spread Functions (LSF) were derived by differentiation
of the analytical approximation.
10
Modulation Transfer Functions (MTF) were obtained after
applying the discrete Fourier transform to the LSF.
Dl"4""lQSD
Average values of MTF at the Nyquist spatial frequency for
five panchromatic acquisitions are as follows: 8a.ir2S6VKlm.pcTAR(irn.tll
-
0.12 i 0.04 for the Georaw images, and
- 0.09 i 0.04 for the Basic image products.
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8.m1~~1161CKb.1.1ABOET~fIt
OrbVlew-3 panchromatic images used for the SpaUal resolution characterization
and the results d these enluatlons shown as values dthe Modulation Transfer
Function at tho Nyquist spatial frequency.
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