accuracy of photomod aerial triangulation, ivan katzarsky, vanya petrova accuracy of photomod aerial...
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ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
ACCURACY OF ACCURACY OF PHOTOMOD AERIAL PHOTOMOD AERIAL
TRIANGULATIONTRIANGULATIONIvan KATZARSKY, Vanya PETROVAIvan KATZARSKY, Vanya PETROVA
GIS SOFIA Ltd., BulgariaGIS SOFIA Ltd., Bulgaria
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
• For evaluation the capacity of a digital photogrammetric system of special
importance is the accuracy of the aerial triangulation
• An experiment in 4 variants in Photogrammetry Department at GIS
SOFIA Ltd. determines the accuracy of PHOTOMOD
INTRODUCTION
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
SOFIA SOFIA MUNICIPALITYMUNICIPALITY
Test areaTest area
TEST AREA
• Contractor: Hansa Luftbild Sensorik und Photogrammetry GmbH, Münster
• Execution of the photo-flight: 19.05.2006
• Aircraft: Cessna 404 Titan
• Aerial camera: Zeiss RMK TOP 30/23 (Z/I Imaging)
• Overlap between the pictures: forward 60 %, side 30 %
• Aerial film: Kodak Aerocolor Negative 2444 III, 19 DIN
• Film processor: Colenta
• Area: 3103 hectares
• Terrain: flat, lightly hilly and hilly not dense urban area with predominantly
low houses
• Average height of the terrain above sea level: 750 m
Test area characteristics
Aerial photography
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
DELTASCAN
GeoSystem Scientific Production Enterprise
12 μm pixel size
Scanning
Pre-marked on the terrain ground control and
check points, determined by GPS-receiver
Topcon GGD with an accuracy of ± 2 cm
in position and ± 3 cm in height
Land surveying
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
General information
EXPERIMENT DESCRIPTION
• Blocks of aerial pictures……………………………………………….. 1
• Strips of aerial pictures………………………………………………… 6
• Aerial pictures…………………………… 14+17+18+18+19+19 = 105
• Approximate picture scale…………………………………….. 1 : 4710
• Average flight height above the terrain, m……………………… 1440
• Ground pixel size, cm………………………………………………. 5.7
• Pre-marked points on the terrain……………………………………. 36
• Pictures per 1 pre-marked point……………………………………… 3
• Tie points…………………………………………………………….. 786
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
Scheme of the experimental block
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
Experimented variants
• PHOTOMOD Montage Desktop
• PHOTOMOD AT
• PHOTOMOD Solver
Aerial triangulation by PHOTOMOD 4.2 modules
Polynomial correction of 2nd degree in X, Y and Z axes are applied
VariantsGroundcontrolpoints
Check pointsPictures
per 1 GCPPictures
per 1 ChP
I 25 11 4.2 9.5II 20 16 5.2 6.6III 15 21 7 5IV 10 26 10.5 4
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
The accuracy of aerial triangulation is evaluated by mean square
differences between geodetic and photogrammetric coordinates
of the ground control and check points
RESULTS
Accuracy on the terrain, based on ground control points
Mean square differences between geodetic andphotogrammetric coordinates of the ground control pointsVariants
in X-axis in Y-axis in XY-plane in Z-axisI ± 3.3 cm ± 3.7 cm ± 5.0 cm ± 7.1 cmII ± 3.3 cm ± 3.4 cm ± 4.8 cm ± 5.5 cmIII ± 3.2 cm ± 3.5 cm ± 4.8 cm ± 4.8 cmIV ± 3.8 cm ± 1.1 cm ± 4.0 cm ± 2.3 cm
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
Accuracy on the terrain, based on check points
Mean square differences between geodetic andPhotogrammetric coordinates of the check pointsVariants
in X-axis in Y-axis in XY-plane in Z-axisI ± 4.5 cm ± 4.3 cm ± 6.3 cm ± 8.0 cmII ± 5.7 cm ± 5.7 cm ± 8.1 cm ±14.4 cmIII ± 6.5 cm ± 5.8 cm ± 8.7 cm ±14.4 cmIV ± 7.3 cm ± 9.3 cm ±11.8 cm ±26.7 cm
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
ANALYSIS
The mean square differences between geodetic and photogrammetric
• In X-axis : ± 3.2 cm to ± 3.8 cm
• In Y-axis : ± 1.1 cm to ± 3.7 cm
• In XY-plane : ± 4.0 cm to ± 5.0 cm
• In Z-axis : ± 2.3 cm to ± 7.1 cm
co-ordinates of the ground control points are in the following range
The mean square differences between geodetic and photogrammetric
co-ordinates of the check points are in the following range
• In X-axis : ± 4.5 cm to ± 7.3 cm
• In Y-axis: ± 4.3 cm to ± 9.3 cm
• In XY-plane: ± 6.3 cm to ± 11.8 cm
• In Z-axis: ± 8.0 cm to ± 26.7 cm
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
CONCLUSIONS
• PHOTOMOD aerial triangulation, based on one ground control point
per 4 to 7 pictures, shows best result
• The results strongly depend on the experimental conditions and
parameters. It gives an idea only for the capacity of PHOTOMOD
aerial triangulation. Another experiment could show other results
• Aerial triangulation carried out by PHOTOMOD shows a reliable
accuracy
ACCURACY OF PHOTOMOD AERIAL TRIANGULATION, Ivan KATZARSKY, Vanya PETROVA
THANK YOU FOR YOUR ATTENTION!THANK YOU FOR YOUR ATTENTION!
Assoc. Prof. Dr. Ivan Katzarsky
22 Omourtag Street
BG-1124 Sofia, Bulgaria
Tel.: +359 (0)2 8466953
GSM: +359 (0)88 5325509
Vanya Petrova, M.Sc.
GIS SOFIA Ltd., Photogrammetry Dept.
5 Serdica Str., BG-1000 Sofia, Bulgaria
Tel.: +359 (0)2 9238338; 9307946
GSM: +359 (0)88 6067306
Authors