GEOMETRIC CORRECTION OF LINEAR ARRAY SENSOR DATA 
Shunji Murai and Ryosuke Shibasaki 
Institute of Industrial Science 
University of Tokyo 
7-22, Roppongi, Minatoku 
Tokyo, Japan 
ABSTRACT 
The Study deals with the following items: 
1) Production of simulated stereo images which 
will be obtained from linear array sensor, by 
using the digital terrain model (DTM) and the 
corresponding scene corrected LANDSAT MSS data. 
2) Determination of exterior orientation parameters 
given as the function of time, by using ground 
control points. 
3) Automated three dimensional measurement by 
applying auto-correlation to the stereo imagery. 
Computer simulation was done for the test area 
where the national elevation data bank and scene 
corrected LANDSAT data are available. The test 
area was selected in the mountaneous area includ- 
ing high mountaines covered with snow, flat plane, 
rivers, reservoirs and so on. 
Simulated stereo images were generated by 
computer with a given exterior orientation para- 
meters. Two different stereo angles of 30? and 
45? were compared. 
A mathematical model to determine the orienta- 
tion parameters was developed with use of ground 
control points which were selected in the imagery. 
Accuracy of exterior orientation was compared 
for two different stereo angles. Standard devia- 
tion of residuals ranges 0.3 to 0.5 pixel around 
the control points, while 0.3 to 1.0 pixel for 
unobservel points. 
Three auto-correlation methods to recognize 
the conjugated points in the stereo imagery, were 
compared with respect to the accuracy and comput- 
ing time. As the result of comparison, minimum 
alsolute sum method were selected as the optimum 
method. 
SIMULATED STEREO IMAGERY 
  
Computer simulation was done for the following 
variables. 
. Stereo angle 
. Satellite orbit 
. satellite attitude 
Following data are given as known input data. 
configuration of earth surface 
. ————— given by national elevation data bank 
23 
. allocation of elements of array sensor 
. radiance value which will be reflected the 
earth surface 
-—---- given by LANDSAT MSS data 
Simulated imagery for linear array sensor was 
obtained as follows: 
1) Input those data of satellite orbit ( X, (L), 
Yo (1), Zo (L), and satellite attitude (uXL), 
¢ (L), x (L)) as the function of line number. 
2) Generate a beam connecting each element and 
and the projection center. 
3) Determine the cross point of the beam and the 
earth surface. 
4) Interpolate the radiance value from the geogra- 
phically corrected LANDSAT MSS data. 
Fig. 1 shows the schematic geometry of linear 
array sensor and DTM. 
Fig. 2 show the topographic map in the test 
area. 
Fig. 3 shows the computer simulated imagery. 
EXTERIOR ORIENTATION 
  
Exterior orientation parameters are given as 
the function of time or line number, as follows. 
satellite orbit: 
Xo = Xoo + X, .L 
Yo = Yoo t Y, .L 
Zo = Zoo + 21 .L 
satellite attitude: 
Q =wo +w3.L Ha Le +03. L° 
$ 7$o *$i.L +62.L° +63.L 
K =K9 +K;.L 4K2.L? H3. L? 
where L : line number 
( Xo , Yo , Zo ) : projection center 
(0. , à, K ) : attitude (roll,pitch 
and yaw)