Abstract

Use of Modern Airborne Digital Sensors for Large Scale Mapping, Surveying and Infrastructure Development in Africa

Kenneth Smillie
Sales Director-Airborne Sensors Leica Geosystems AG Heerbrugg, Switzerland

Over the past years there have been significant changes in airborne sensing capabilities. This paper will explore the advantages of aerial data acquisition by means of new airborne digital sensors for improving the accuracy, quality and efficiency of digital mapping products. These improvements can and should be used to accelerate the renewal of large scale mapping to assist in infrastructure developments in Africa. Especially in the fields of large scale mapping, map updating, surveying, infrastructure development, orthomap production or the creation of high accuracy elevation data - a fully digital acquisition and workflow has been shown to be greatly advantageous. Looking at the present infrastructure situation in Africa one can see potential, as well as the demand, for high accuracy data derived from airborne sensors. Once captured this data can efficiently be processed shortly after the survey flight and widely distributed to all concerned stakeholders involved. Infrastructure development can now be based on newly acquired digital data rather then historical information and small scale topographic maps.

A number of ancillary new technologies and software have also been developed in addition to airborne hardware. The calculation of airborne GPS positions using Precise Point Positioning (PPP) has reduced restrictions when executing survey flights in remote areas. With PPP it is now possible to undertake survey flights without using a fixed GPS reference station on the ground, and yet still obtaining sufficiently accurate directly georeferenced imagery or LiDAR captured points The Leica airborne sensors developed to acquire this broad range of high-resolution data are leading the way in both the imaging and laser scanning markets. These sensors and recent technology breakthroughs will be reviewed. This includes key aspects of their workflow and how Leica provides the total solution from flight planning to in-flight data capture to preparing the data for careful photogrammetric and point cloud analysis. Finally, as progress seems to be accelerating year after year in this digital sensor age, some thoughts on future sensor and workflow developments are presented.