TOWARDS THE FULL AUTOMATION OF LASER SCANNING AND AERIAL 
PHOTOGRAPHY DATA PROCESSING 
Dr. E. Medvedev 
Geokosmos, R&D Directorate, 14, build. 20, B. Ordynka str., Moscow, 119017, Russia, 
eveeniy medvedev@egeokosmos.ru 
Commission PS WG 11/2 
KEY WORDS: Laser scanning, LIDAR, Mapping, Orthorectification, Automation, Digital Terrain Model 
ABSTRACT: 
The theoretical conclusions and practical results described in this article are based on the extensive experience of 
geodetic, photogrammetry and aerial survey works that are being implemented by Geokosmos in Russia and globally as well. 
Being a commercial service providing company, Geokosmos is greatly interested in obtaining technologies for aerial survey 
data processing with extremely short duration of technological cycle while applying such data for generating up to 1:1000 
topographical maps. The time factor is rather critical in modern Russia, taking into account the huge Russian territory and the 
strong demand for various topographical and remote sensing data provoked by intense post-Soviet economic processes. Aerial 
data acquisition is implemented using Geokosmos" helicopter or fix-wing platforms equipped with Optech airborne laser terrain 
mappers ALTM 2050, 30/70, digital aerial cameras, infra-red sensors, GPS/GLONASS systems and some auxiliary devices. 
Joint collecting and ultimate combining of LIDAR and aerial photography data is the crucial point of the company's strategy in 
both methodological and marketing aspects. Specifically, such an approach makes it possible to reduce the entire processing 
time and therefore dramatically increase productivity. All these considerations lead to the necessity of automation of all stages 
of combined LIDAR & aerial photography data processing aimed at topography map making. 
The proposed approach to realising the complete automatic technology have been described in this paper based on the 
experience gained by Geokosmos during the last 5 years. The main achievements and disadvantages have been discussed, 
especially concerning the maximum achievable accuracy of the method. 
1. GENERAL CONSIDERATIONS 
The combination of laser scanning and digital aerial 
photography seems to be very promising for the following 
reasons: 
these two types of data, namely, laser detection and 
ranging and acrial photography data, supplement cach 
other to the utmost extent when they are used to 
produce large-scale maps and plans, 3D semantic 
models and other geoinformation objects. Indeed, 
laser scanning data provide detailed information on 
terrain features and allow the automatic creation of 
Digital Terrain Models (DTM) as well as models of 
geographic objects having distinct morphology like 
power transmission lines, forests, etc. On the other 
hand, digital aerial photographs give a natural 
presentation of the scene thus allowing the decoding 
and identification in the office of meaningful contours 
of objects that cannot be identified otherwise using 
laser data only. 
laser scanning and digital aerial photography can be 
readily combined in practice. Weight, dimensions and 
power consumption of modern laser scanners and 
digital cameras allow their easily mounting on light 
aircraft of almost any type, both on planes and 
helicopters, so that these two types of survey can be 
performed concurrently from the same aircraft. It is 
noteworthy that laser detection and ranging data are 
by definition supported by a complete set of exterior 
orientation parameters due to airborne GPS 
(GLONASS) receiver and inertial navigation system 
176 
like POS/AV from APPLANIX or IGI. Therefore 
exterior orientation parameters can be applied, for no 
extra cost, to all aerial photographs taken with an 
accuracy within 5-6 cm for spatial coordinates of the 
point being photographed, and within 0.5-1.0 mrad 
for camera's optical axis angular orientation. 
Although this degree of accuracy may be insufficient 
in some cases, these data can be useful as initial 
approximations. for the final image orientation 
through phototriangulation, both for the processing of 
survey path data and sets of aerial photographs. 
The possibility to develop absolutely new algorithms 
of geomorphological analvsis is probably the most 
interesting aspect of combining laser scanning and 
digital aerial photography data, such algorithms being 
capable of using both types of data to reproduce 
terrain features and ground objects, and perform high- 
precision spatial geometric measurements. The latter 
assumption requires some comments. The application 
of laser scanning and aerial photography (for 
subsequent stereophotogrammetrie processing) makes 
it possible to achieve similar results in 3D modeling 
of terrain features and of the entire ground 
infrastructure of the scene being surveyed in general. 
In both cases, models of the terrain surface can be 
generated, outlines of buildings and structures can be 
determined, and plan and vertical measurements can 
be taken. The following notes are very important: 
1) All above-mentioned methods of 3D modeling of 
the surveyed scene and its individual components as 
well as geometric measurements are performed 
independently meaning that various sources of data 
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