School of Surveying and Spatial Information Systems

The University of New South Wales


Mobile Mapping System: Concept & Current Development 

by Wei. H Chan

Supervised by Dr. Jinling Wang

 

October 2004


Abstract

This research reviews the evolution of Mobile Mapping System (MMS) from photolog pictures to the current modern multi-sensor data acquisition systems that support different platforms. Different positioning techniques used in MMS are examined with emphasis on GPS/INS integration, while the preferred sensors use is also highlighted.

The backbone technology for MMS, direct georeferencing, is reviewed with experiments conducted by various research groups. System calibration is one of the important factors that influence the accuracy of MMS. This is also discussed in depth. The different aspects that will be expected to benefit MMS in future are also discussed. In addition, a collection of literature related to MMS is compiled and presented by a webpage.

 

Objectives

The concept of Mobile Mapping has evolved over the last decade to improve the efficiency of spatial data collection and it is designed to be installed on various land based and airborne platforms.

 The aim of this project is:

(a)           to review the historical development and current status of MMS,

(b)          to discuss the basic concepts and principles, and

(c)           to analyse the factors that affect its performance and future trends.

 

Overview

A Mobile Mapping System (MMS) can be defined as a kinematic platform, upon which multiple sensors have been integrated and synchronized to a common time frame, to provide three-dimensional near-continuous and automatic positioning of both the platform and simultaneously collected geo-spatial data.

At the present time, spatial data are highly in demand for the inputs into GIS (Geographical Information System) databases. Traditional techniques of data collection, such as using total stations, are too expensive or time consuming and aerial photographs on the other hand could not provide sufficient detailed information. Therefore, to find a way to capture data efficiently is important to generate new databases and to update existing databases for applications such as highway and facility mapping, roads inventory, natural resources inventory, utility management and city planning.

The main components of MMS are the navigation and imaging sensors. The most important aspect for MMS is direct georeferencing. This is made possible due to the integration of GPS and INS to provide exterior orientation with six parameters: projection centre coordinates (X0, Y0, Z0) and the rotations around the three axis omega (ω), phi (φ) and kappa (κ) of the mapping sensor without having any ground control points. Figure 1 shows an example of a land-based MMS GPSVisionTM from Lambda Tech International. This is particularly useful for aerial photogrammetric mapping as it eliminates the traditional aerial triangulation, which is labour and time intensive. An integrated Kalman filter is then applied to combine the GPS and inertial solutions. 

 

Figure 1: Land based MMS GPSVisionTM from Lambda Tech International

Major Components of MMS

MMS consist of two major components: namely the positioning and imaging sensors. The positioning component mainly comprises of GPS and INS. In addition, other dead reckoning sensors such as odometer and digital magnetic compass, are used for integration to perform direct georeferencing.  The imaging sensors may be in a form of digital (CCD) based or video cameras, Laser Range Finder, LIDAR, InSAR and Multi/hyper spectral sensors (airborne systems) .  Table 1 summarised the primary sensors and functionality of MMS.

 

Table 1: Primary sensors and their functionality

 

Conclusion 

The development of MMS has gone through major changes from photolog to multi-sensors systems integration with the ability to support kinematic platforms in land and airborne environments. Integration of INS/GPS is the preferred positioning technique to perform direct georeferencing as it is able to support high accuracy imaging sensors that operated in a continuous scanning mode such as a laser scanner.

One of the most important factors that influenced the accuracy of direct georeferencing is sensors calibrations. It is important that all sensors are well calibrated, especially boresight misalgnment, and referenced to a common coordinated frame.

 The high cost of MMS is mainly due to the high price of INS components and the large CCD chip. However, the cost is likely to drop as the MMS community is becoming bigger and will continue to expand. The trend of MMS is moving towards low cost, advanced real time image processing, automated data flow and fast wireless transfer of spatial data. All these can be expected in the future as enhancement of third generation wireless technology 3G, mobile GIS, telegeoinformatics and Galileo progresses.

 

Useful Links

The following links are some companies, universities and conference/journal papers that related to MMS.

Companies

Applanix Corporation,Canada - Integrated inertial/GPS  products for commercial applications

ARRB Transport Research, Australia - Australia's leading provider for value-added research and technical services addressing transport problems

Ingenieur-Gesellschaft für Interfaces mbH (IGI), Germany - Integrated inertial/GPS  products for commercial applications

 

Universities

Ohio State University, Columbus, USA - Centre For Mapping

University of Calgary, Canada - Satellite-Based Positioning and Navigation Group, Department of Geomatics Engineering

University of New South Wales, Sydney, Australia - Satellite Navigation and Positioning Group, School of  Surveying and Spatial Information System

 

Conference/Journal Papers

Ellum C. and El-Sheimy N. (2002). Land-Based Mobile Mapping System, Journal of the American Society for Photogrammetry and Remote Sensing, (68) 1, January, p.13-17. Download

Grejner-Brzezinska D., Li R., Haala N., and Toth C. (2002). Multi-Sensors System For Land-Based and Airborne Mapping: Technology Of The Future?, ISPRS Commission II, Symposium, Xi'an, China August 20-23.Download

Cramer, M., Stallmann, D. & Haala, N. (2000). Direct Georereferencing Using GPS/Inertial Exterior Orientations for Photogrammetric Applications. IAPRS Vol. XXXIII Part B3/1 pp. 198-206. Amsterdam. 2000. Download

 

Further Information

For more information, please contact:

Dr. Jinling Wang
Email: jinling.wang@unsw.edu.au 

Mail:
School of Surveying and Spatial Information Systems
University of New South Wales
UNSW SYDNEY NSW 2052
Australia

Phone: +61-2-9385-4205

Fax: +61-2-9313-7493

WWW: http://www.gmat.unsw.edu.au