International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B3. Istanbul 2004
Geodetic coordinates of these points are measured by Topcon
GTS4 Total Station. Images, which have 1/10000 and 1/16000
scale, were used. Description of flying information both
1/10 000 and 1/16000 photographs scale is given in the Table 2.
Photographs (1/10000 scale) are restitutied by Zeiss Planicomp
P3 analytical instrument. Photographs that have 1/16000 scale
were scanned by ZEISS SCAI Photogrammetric Scanner. Pixel
size is 21 pm. The data sets which were obtained from
photographs (1/16 000 scale) were restitutied by PHOTOMOD
and eComputer Imaging software which was developed by
E.Coskun and H.Karabork. Today, PHOTOMOD software is
recognized as one of the most popular digital photogrammetric
system in Russia. Photomod product line utilises latest advances
in digital mapping theory and is put to every day work in many
production facilities worldwide.
Photomod functionality is summarized as below:
e Central projection and pushbroom scanner imagery
processing,
e Aerial triangulation,
e Automatic DTM extraction,
e Orthomosaic generation,
e On-screen 3D-digitizing in stereo mode,
e Orthomonoplotting,
e Digital maps creation and output
e DTP scanner calibration.
Montage Desktop Module is the main system used to create,
delete, copy, import project; enter camera passport data and
start all other system modules.
AT/Solver Module performs a full set of digital aerial
triangulation computations for the block of images.
DTM Module provides a set of tools to create DTM (as
triangulated irregular network-TIN) and contour lines.
Stereo Draw Module is a module of 3D feature extraction.
Mosaic Module is used to create seamless orthomosaic from
source block images.
Vector Module is a powerful vector —based GIS and desktop
cartography system used to create, edit and print out digital
maps including cutting and merging standard map sheets.
Stereo Vector Module is used basically for vector maps
updating and supports working with two monitors.
ScanCorrect is designed for the geometric calibration of
desktop scanner (Photomod 2000) .
eComputer Imaging software has modules for image
enhancement, interior orientation, bundle adjustment and digital
elevation models (Karabork 2002).
Table 2. Description of flying information both 1/10 000 and
1/16000 scale of photograph
1/16000
Photo Scale
1/10000
Photo Scale
October 1998
Flying date September 1995
Flying direction East-West East-West
Forward overlap %60 %70
Side overlap %30 0020
Camera WILD RC-8 ZeissRMKATOP30
Photographs Size 23 cm*23 cm 23 em*23 em
Focal length 153.29 mm 305.339 mm
1550 4900
Flying Height(h)
3.3 Description of Procedure
The data sets which were obtained from restitution of
photographs (1/10000 scale) on Zeiss Planicomp P3 analytical
instrument were derived from selective, progressive and
composite sampling methods. The grids obtained from
progressive sampling method were measured in 25 m by 25 m
intervals in X and Y directions. More than 1500 points were
measured with analytical instrument in progressive sampling
method. Feature-specific points were measured in selective
sampling method. More than 2500 points were obtained from
analytical instrument in this method (Karabork 1996).
440 points is directly measured on PHOTOMOD software by
means of stereoscopic model. The test area is gridded on
eComputer Imaging software. The these grids were measured in
10 m by 10 m intervals in X and Y directions. More than 10
000 points were obtained from this software.
Heights of 440 points in test area were calculated by bilinear-
interpolation method. This equation is written for the four
points, which are nearest points to point at which the Z
coordinate is sought.
ZzatX*aitY*gtrxt*Yt*a (3)
where
ag, 41,82, az 7 bilinear transformation parameters
X.Y = plane coordinates of point in object
system
Z = height of point
eComputer Imaging software follow below steps for generation
DEM.
^
I. Needed inputs are entered in the DEM window. (Fig.3).
(Inputs are names of stereo pair, first coordinates and grid
interval).
IL. Image coordinates of point, at which plane coordinates (X,
Y) are known, are calculated by Eq.4.
I *«(X-X)*5, *«(Y-Y,)*5, «(Z-Z.)
JE #(X-X,)+1, *(Y-Y,)*t; «(z-z,)
(4)
Tp» *«(X-X,)*6, *(Y-Y,)*r, «(z-Z)
I; *(X-X,)*15 *(Y-Y,)*5, «(Z-Z.)
XX, C*
va ET
Xo, Yo, Zo, O, ©, x values are calculated before in bundle
adjustment module.
International Arc
UE EE ESS
Xo, Y Zo
e
X,Y
Xo, Yo
Tjj, F12 , F3.
I5, F22; T23,
T31> l'32, T33
X.Y. Z
eComputer Imaging
ll. Digital Elevation Model...
Project Property ——
| File Name : [ker
DEM File : [oia
Grid Space (mi: fio
x: 421
Y: 456
2: 114
plmages
Figure 3. DEM ı
III. Image coord
this transformati
before in interioi
III, coordinates 1
coordinates (X, *
dy;
b
[0
bi; 2j.
where
40, 4, Aa, L
Xi yj
j
X
IV. The window
Step IIL, are selec
