Using DSS digital camera images and DТM from ALS50 laser scanner for creating orthomosaics in PHOTOMOD system Dmitry V. Кochergin (Racurs), Maxim V. Skorniakov (Mosgiprotrans)

On-board data + software Digital aerial images Exterior orientation parameters DTM from Laser scanner TerraScan software PHOTOMOD software

PHOTOMOD 4.1 – automatic interior orientation of images from the digital camera

PHOTOMOD 4.1 – importing exterior orientation parameters from Applanix format

PHOTOMOD 4.1 – block layout creation from the exterior orientation parameters

PHOTOMOD 4.1 – automatic tie points measurements using the block layout

PHOTOMOD 4.1 – import of laser scanner data from LAS format

+ automatic tie points measurements + automatic tie points measurements + ground control points Digital aerial images, Exterior orientation parameters, DTM from Laser scanner Orthomosaics of different accuracy Input, processing, output direct georeferencing block adjustment

reconstruction of existing highways and railroads and projecting new ones aerial survey: DSS camera (focal length = 35 mm) Applanix ALS 50 Flight height 300 m Air vehicle Mi-8 helicopter Total length 180 кm Aerial survey productivity 150 km per day Velocity km\h one of the projects in 2006: output products: DEM Orthomosaics of 1:1000 scale 3D vector objects MOSGIPROTRANS Co. is the biggest Russian institute of exploration and projecting of transportation objects

How does it look like

Calibration of DSS-ALS50 system was done in accordance with standard Applanix technology on the special polygon

Project geodetic works GCPs (also for more precise field survey and calculation of accurate local datum parameters) Tacheometry Base stations for ALS and DSS (Applanix postprocessing) “Moscow” coordinate system

PHOTOMOD 4.1. One of project strips (35 images)

PHOTOMOD 4.1. Automatic interior orientation

PHOTOMOD 4.1. Block layout after importing Applanix data

PHOTOMOD 4.1. Automatic tie points measurements

PHOTOMOD 4.1. Block adjustment

TerraScan. All points ~8 points / sq.m ~ points / image

TerraScan. “Ground” points ~2 points / sq.m ~ points / image

TerraScan. “Model key” points ~0.2 points / sq.m ~ points / image

PHOTOMOD 4.1

PHOTOMOD 4.1 Laser scanner data The biggest LAS file imported to PHOTOMOD was about points

PHOTOMOD 4.1

PHOTOMOD 4.1 DEM from laser scanner data

PHOTOMOD 4.1 Orthomosaic

+ automatic tie points measurements + automatic tie points measurements + ground control points orthomosaic accuracy by check points (max residual) 30 cm25 cm15 cm Digital aerial images, Exterior orientation parameters, DEM from Laser scanner Accuracy and productivity  Total time for 35 images project processing is about 10 hours direct georeferencing block adjustment

Thank you for attention!