VIIth International Scientific and Technical Conference From Imagery to Map: Digital Photogrammetric Technologies

Bundle Adjustment Method in Bundle Adjustment Method in

PHOTOMODPHOTOMOD®® 4.3 4.3

Andrej Yu. Sechin, Scientific director, Racurs

September 17-20, 2007, Nessebar, Bulgaria

Selecting a method of adjustmentSelecting a method of adjustment

Tests on “synthetic” projectsTests on “synthetic” projects

Over 100 parametersOver 100 parametersTested on blocks up to 3000 imagesTested on blocks up to 3000 images

Tests in Racurs Production DepartmentTests in Racurs Production Department

More than 50 real blocks adjusted.More than 50 real blocks adjusted.Scales 1:10000-1:40000.Scales 1:10000-1:40000.From 20 to 1000 images per projectFrom 20 to 1000 images per project

New parameter: AccuracyNew parameter: Accuracy

Block of 2000 imagesBlock of 2000 imagesXYZ deviations ~ 0.40mXYZ deviations ~ 0.40m

Comparing different programsComparing different programs

Two synthetic test blocksTwo synthetic test blocks1000 images, 30000 points, 40 GCPs,1000 images, 30000 points, 40 GCPs,H=2000m, f=150mm,Scale – 1:13000H=2000m, f=150mm,Scale – 1:13000Deviations – 10 mkm (image), 20 cm(XYZ)Deviations – 10 mkm (image), 20 cm(XYZ)

2000 images, 60000 points, 75 GCPs,2000 images, 60000 points, 75 GCPs,H=2000m, f=150mm,Scale – 1:13000H=2000m, f=150mm,Scale – 1:13000Deviations – 10 mkm (image), 40 cm(XYZ)Deviations – 10 mkm (image), 40 cm(XYZ)

Computers usedComputers used

PHOTOMOD/Aerosys PHOTOMOD/Aerosys Celeron 2.8 GhzCeleron 2.8 GhzPhotocom(Antipov)Photocom(Antipov) Pentium 4 3 Ghz Pentium 4 3 Ghz OrimaOrima Core2Duo E6400Core2Duo E6400

Comparing different programsComparing different programs

I. 1000 Images synthetic block (40 GCPs)I. 1000 Images synthetic block (40 GCPs)

MethodMethod CPU TimeCPU Time ErrXErrX ErrYErrY ErrZErrZPHOTOMOD(Models)PHOTOMOD(Models) 0’18’’0’18’’ 9.19.1 9.89.8 24.324.3PHOTOMOD(Bundles)PHOTOMOD(Bundles) 2’43’’2’43’’ 7.07.0 8.68.6 16.716.7Photocom(Antipov)Photocom(Antipov) 4’4’’4’4’’ 6.66.6 8.78.7 16.316.3AerosysAerosys >4h>4h 7.47.4 10.010.0 53.353.3Orima(*)Orima(*) 1’14’’1’14’’ 6.66.6 8.28.2 16.116.1

II. 2000 Images synthetic block (75 GCPs)II. 2000 Images synthetic block (75 GCPs)

MethodMethod CPU TimeCPU Time ErrXErrX ErrYErrY ErrZErrZPHOTOMOD(Models)PHOTOMOD(Models) 0’48’’0’48’’ 10.610.6 11.711.7 28.728.7PHOTOMOD(Bundles)PHOTOMOD(Bundles) 10’23’’10’23’’ 8.38.3 8.68.6 19.919.9Photocom(Antipov)Photocom(Antipov) 20’12’’20’12’’ 7.47.4 7.57.5 19.219.2Orima(*)Orima(*) 4’54’’4’54’’ 7.27.2 7.07.0 18.618.6

When bundles is to be usedWhen bundles is to be used

IMU/GPS DataIMU/GPS Data

When bundles is to be usedWhen bundles is to be used

““Big” water areas on the imagesBig” water areas on the images

Example project:Example project:1:12000 image scale1:12000 image scaleBundles:Bundles:GCPs RMS residualGCPs RMS residual17 cm – XY17 cm – XY16 cm – Z16 cm – ZModels:Models:RMS residual 2.6 timesRMS residual 2.6 timesas bigas big

General Considerations/ExperienceGeneral Considerations/Experience

• For regular projects with no blunders the accuracy is similarFor regular projects with no blunders the accuracy is similar• Each method allows to detect specific blundersEach method allows to detect specific blunders• Independent models is better for controlling GCPsIndependent models is better for controlling GCPs• For final adjustment it is better to use “bundles”For final adjustment it is better to use “bundles”

Independent models vs. Bundle AdjustmentIndependent models vs. Bundle Adjustment

Usage schemeUsage scheme

Models/detectingModels/detectingtie blunderstie blunders

Bundles/detectingBundles/detectingtie blunderstie blunders

Models/detectingModels/detectingGCP blundersGCP blunders

BundlesBundles(increased accuracy)(increased accuracy)final adjustmentfinal adjustment

PHOTOMOD SolverPHOTOMOD Solver

Future DevelopmentsFuture Developments

•Self calibrationSelf calibration•Robust blunder detectionRobust blunder detection•Speedup, using sub-blocks for adjustmentSpeedup, using sub-blocks for adjustment•Various accuracy estimationsVarious accuracy estimations

Thank You for AttentionThank You for Attention

More Information at the Master ClassMore Information at the Master ClassEverybody is InvitedEverybody is Invited