12
January 2016
PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
The aero-triangulation software used was various editions
of MUSAT (Multiple Station Analytical Triangulation)
developed by the Autometric Operation (first headed by
Fred Doyle, later by Atef Elassal as the Team Leader for the
various MUSAT versions) for the Army Map Service, then
Army Topographic Command (TOPOCOM), then DMA/HTC,
and then NIMA.”
The stereo pair transparencies from the Rectifier were
ultimately passed to the National Archives and Records
Administration (
)
M
ap
M
aking
from
C
orona with
L
ittle
or
N
o
G
round
C
ontrol
Problems in making maps of the former Soviet Union and
China from the Corona images with little or no ground control
information and deliberate distortion in Soviet maps are
discussed by Baclawski (1997), D.A. Day (1998), J.M. Logsdon
and B. Latell as well as Cloud (2002) and K. Brunner (2015).
Much was learned from documents captured by the Germans
from the Russians early in World War II and later recovered
by US forces in 1945 near Saalfeld in Thuringia where the
geodetic archive of the Wehrmacht was stored to protect it
during the bombing of Berlin.
F. W. Hough (1958), later of the National Geospatial-
Intelligence Agency, led the team which retrieved the German
geodetic and map archives. Among many useful things,
these maps contained astronomically determined geographic
coordinates of the wooden towers used for the planning of the
Trans-Siberian railway (1891 - 1916) and whose remains can
still be seen in some Corona images. Irene K. Fischer (2015) was
the geodesist who first calculated a new Earth ellipsoid from
satellite measurements and named it in honor of F.W. Hough.
This was used for accurate targeting of anti-ballistic missile
systems and was the predecessor of ellipsoid measurements
which culminated in the WGS84 and its successors.
Hough (Fischer, 1959) ellipsoid latitudes and longitudes from
1960 from the USGS metadata were used in Corona for initial
georeferencing according to Sealander (1997). Constants are
not available for datum transformation of Hough latitudes
and longitudes to the WGS84 ellipsoid for comparison with
Google Earth. Errors introduced may be as much as 30 meters
or more at middle latitudes. An approximate correction
reduces the error so that rough searches for preliminary
georeferencing in strip areas are possible.
S
oftware
R
eduction
of
G
eometric
D
istortion
, P
ost
-P
rocessing
and
G
eoreferencing
With equations from the de-classified Gamma Rectifier Report
and Ondrejka (1980), test software was written to emulate the
Gamma Rectifier plus image and satellite motion corrections
as described by (Sohn 2004) with approximate Hough-WGS84
correction as suggested by Clifford J. Mugnier to the first author.
The software processed a full resolution 7.0 micron scanned
USGS strip (4 stitched sections totalling 110,000 x 8000 pixels)
in less than 90 seconds on a modern machine. By using a
mathematical model from the optical design, all five principal
types of optical distortion are reduced significantly. Only a
few ground control points are required for georeferencing to
UTM WGS84 after rectification.
Q
ualitative
T
est
A test object near the high distortion end of a KH-4B Corona
strip through Nalbandyan, Armenia, which has a pattern
of accurately laid-out circular streets and houses visible in
Corona and in Google Earth Pro, was found by sheer good luck!
This test object, Figure 13, was used for visual estimation
of the quality of the geometric correction in an area of high
distortion. The whole strip can not be reproduced here.
USGS Entity ID: DS1115-2154DF095
Acquisition Date: 1971/09/20
Mission: 1115-2
Frame: 95
Direction Flag: 154D
Image Type: Black and White
Camera Type: Forward
Camera Resolution: Stereo High
Film Type: 70mm Panoramic
Generation: 2
Polarity: Negative
Figure 12. Bunker-Ramo UNAMACE stereo plotter for post-
processing of rectified Corona transparencies AMS 1:250,000
Pictomap.
