—= 240 -
1. Introduction
Since 1976 the STEREOCORD G-2 is produced in series by Carl
Zeiss of Oberkochen, The instrument is a mirror stereoscope
combined with a desk calculator. The stereoscope serves to view
a pair of aerial photographs together with a floating mark. The
image coordinates of the point on which the floating mark has
been set are digitized and transmitted to the desk calculator
via a DIREC-1 interface unit. The calculator converts the image
coordinates into terrain coordinates.
The idea of such a combination of stereoviewing unit and desk
calculator is not entirely new [1 to 6]. Practical applications
of the unit have also been published [7,8] or will be published
in the near future.
What is new is that in the course of the past year new STEREO-
CORD programs have been developed at the Stuttgart Technical
College. These new programs have considerably improved the
accuracy of the machine. This specific point will be discussed
in chapter 4, while the first part of this paper is devoted to
the operating principle and uses of the instrument.
2. Operating Principle
Figure 1 is a schematic diagram of the STEREOCORD system. This
consists of the STEREOCORD itself, the DIREC-1 interface, the
desk calculator, and the software stored on a magnetic tape
cartridge.
DIREC 1
J
| xa
| px
4
A x e ^ = RESULTS:
STEREOCORD IY = C 775 COORDINATES
y . 14 DISTANCES
sy ANGLES
AREAS
PARAMETERS : Ru uv V 7 VOLUMES
CAMERA FOCAL LENGTH. Z7 vA
FLIGHT HEIGHT +
TILTS @,, 94,9,
9 2 DESK CALCULATOR
Fig.1: The STEREOCORD system
The stereo pair to be viewed through the mirror stereoscope is
positioned on & mobile photocarriage. The position of the latter
(x',y' image coordinates) and of the right hand photo in relation
to the left hand one (x-parallax px) is digitized and trans-
mitted to the desk calculator via the DIREC-1 interface. The
x',y,px -coordinates are then used by the calculator to compute
the terrain coordinates X, Y, H with the aid of the software.
Camera focal length, flight height and the photo tilts @1, 2,
