lows to
; Spatial
attening
1 py
ne zero
cross of
| angles
rovides
eme of
nera
llows it
ng axis
is. V-V'
around
ion of
Ig on
tor are
| is the
> group
nd for
ecision
photo-
rovides
mode,
ivity of
ctronic
ty of
isopancromatic film with OS-14 light filter, which
excludes influence of chromatic distortion.
Resulting from the measurements on comparator
photogrammetric distortion is calculated as:
6x7 Xx - f tgox *- X, tg^ox (1)
8y 7 yk - f tgoy ^ yo tg^oy Q)
where:
dx dy - meanings of distortion;
Xx, Yk - coordinates of crosses;
9x, 9y - angles measured using spatial comparator;
f - photogrammetric focal length;
Xo, Yo - coordinates of man point.
In order to minimize the value of distortion
photogrammetric focal length and main point
coordinates are calculated under condition
[6x] +[ dy] = min.
When camera is placed into the spacecraft, illuminator
glass is also calibrated. In addition to that gas
environment inside of the spacecraft is measured, and
during the flight actual value of temperature and
pressure are controlled. This allows to consider
influence of illuminator and inner refraction and to make
necessary corrections in camera's focal length
determination. As a result of all on-ground calibrations
and in-flight measurements summarized RMS of TK-350
images is 5 mkm.
Panoramic camera KVR-1000.
Providing high accuracy of stereoscopic images, which
is necessary to define location of ground points in height
and in plane, topographic camera TK-350 let one to
have 10 m ground resolution. For the purpose of
mapping it is also important to know the details of
topographic map. Completeness of the map content
depends mainly on ground resolution, which has to be
near 2 m, i.e. much higher than TK-350 allows to have.
To provide this high resolution on condition of large
swath, KVR-1000 camera was developed in order to
obtain required high ground resolution. In developing of
KVR-1000 camera panoramic photographic solution
was chosen, where high resolution in central part of lens
system viewing field is kept along the whole frame, and
it is possible to obtain significant swath. Main technical
characteristics of this camera are listed below in table 2.
e Focal length 1000 mm;
e Frame FA 80 x 720 mm;
e Viewing angle | 11° 40
man Bl a YL p---------------4
e Relative p 4x5
aperture format !
E.
e Coordinate | at the angles 0°, 10°, -10°
marks I
107
e Time marks with 128 Hz frequency
—————————— SE SE — —
PTT
j by moving mirrors
e Type of
panoraming 5
e Panoraming ; +/- 20° 40°
angle I
e Compensation Loy decentralized mirror
of the image | rotation
shift
e Compensation | less than 1%
shift error |
e Light filter | OS-14, orange
e Imagery shift l available
compensation =
e Slit width j 0.3-15 mm
A I or mo om or me 2 em rr om oe mm
e Longitudinal | 6% - 12%
overlap |
L
Table 2. Technical characteristics of KVR-1000
camera.
Panoramic camera KVR-1000 provides 2 m ground
resolution from 220 km height and 160 km swath.
Thus, the area covered by one TK-350 image is also
covered by 7 KVR-1000 images, when two cameras
operate together as a companion system. Mutual
layout of TK-350 and KVR-1000 images is shown on
Figure 5.
KVR-1000 frames overlap KVR-1000 frames
= 17
» A y A
= j| s
Flight direction 8 8
40 KM.
dl
UM
Figure 5. TK-350 and KVR-1000 image layout.
Panoraming is made by means of rotation of two
mirrors projecting the imagery onto stable slit. In the
process of taking picture film is moving with preliminary
assigned speed, and the exposure is regulated by the
slit width. There are two protecting glasses in a set of
equipment. First one, placed in front of the lens,
provides its protection from external heat flow, and
second one placed beside the lens provides
hermetization of spacecraft descending module. In
front of the slit light filter is mounted. This filter is made
from OS-14 glass, and to control optimal position of
imagery plane seven control filters OS-14 can be
applied. These filters provide +/- 0.3 mm defocusing
with 0.1 mm step. This measure allows to select
optimal positioning of imagery plane. Scheme of KVR-
1000 camera is shown on Figure 6.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B1. Vienna 1996
