Microlight aircraft for radiometric surveying applied to land resources assessment and monitoring in Mali (West Africa)

A microlight aircraft has been used to obtain and record concurrent, near-continuous, spectral responses in the MSS and SPOT bands over various ground features. The experiment was performed in Mali, along the Niger river, during November, 1985. The airborne instrumentation, developed as a prototype for this experiment, also included flying-height measurements by a laser range-finder and a colour video-camera. Spectral data and flying height (5 to 80 m) were scanned every 0.1 s and recorded on the audio channel of a videotape, after multiplexing and analogue to digital conversion (8 channels).

The following conclusions were made:

• 1.

  - the measuring and recording system, although light and simple, proved to be very efficient for automatic survey in a tropical environment;

• 2.

  - spectral reflectance profiles are feasible in a very short time over a wide range of objects;

• 3.

  - height measurements can provide very useful information for the geometric description of the vegetation cover;

• 4.

  - microlight aircraft are proving to be highly suitable as platforms for low-cost aerial survey including large-scale photography and complementary to conventional methods.