Transcript Document

VIIth International Scientific and Technical Conference
From Imagery to Map:
Digital Photogrammetric Technologies
Bundle Adjustment Method in
PHOTOMOD® 4.3
Andrej Yu. Sechin,
Scientific director, Racurs
September 17-20, 2007, Nessebar, Bulgaria
Selecting a method of adjustment
Tests on “synthetic” projects
Over 100 parameters
Tested on blocks up to 3000 images
Tests in Racurs Production Department
More than 50 real blocks adjusted.
Scales 1:10000-1:40000.
From 20 to 1000 images per project
New parameter: Accuracy
Block of 2000 images
XYZ deviations ~ 0.40m
Comparing different programs
Two synthetic test blocks
1000 images, 30000 points, 40 GCPs,
H=2000m, f=150mm,Scale – 1:13000
Deviations – 10 mkm (image), 20 cm(XYZ)
2000 images, 60000 points, 75 GCPs,
H=2000m, f=150mm,Scale – 1:13000
Deviations – 10 mkm (image), 40 cm(XYZ)
Computers used
PHOTOMOD/Aerosys
Photocom(Antipov)
Orima
Celeron 2.8 Ghz
Pentium 4 3 Ghz
Core2Duo E6400
Comparing different programs
I. 1000 Images synthetic block (40 GCPs)
Method
PHOTOMOD(Models)
PHOTOMOD(Bundles)
Photocom(Antipov)
Aerosys
Orima(*)
CPU Time
0’18’’
2’43’’
4’4’’
>4h
1’14’’
ErrX
9.1
7.0
6.6
7.4
6.6
ErrY
9.8
8.6
8.7
10.0
8.2
ErrZ
24.3
16.7
16.3
53.3
16.1
II. 2000 Images synthetic block (75 GCPs)
Method
PHOTOMOD(Models)
PHOTOMOD(Bundles)
Photocom(Antipov)
Orima(*)
CPU Time
0’48’’
10’23’’
20’12’’
4’54’’
ErrX
10.6
8.3
7.4
7.2
ErrY
11.7
8.6
7.5
7.0
ErrZ
28.7
19.9
19.2
18.6
When bundles is to be used
IMU/GPS Data
When bundles is to be used
“Big” water areas on the images
Example project:
1:12000 image scale
Bundles:
GCPs RMS residual
17 cm – XY
16 cm – Z
Models:
RMS residual 2.6 times
as big
General Considerations/Experience
Independent models vs. Bundle Adjustment
• For regular projects with no blunders the accuracy is similar
• Each method allows to detect specific blunders
• Independent models is better for controlling GCPs
• For final adjustment it is better to use “bundles”
Usage scheme
PHOTOMOD Solver
Models/detecting
tie blunders
Bundles/detecting
tie blunders
Models/detecting
GCP blunders
Bundles
(increased accuracy)
final adjustment
Future Developments
•Self calibration
•Robust blunder detection
•Speedup, using sub-blocks for adjustment
•Various accuracy estimations
Thank You for Attention
More Information at the Master Class
Everybody is Invited