A low-cost glacier-mapping system

An old portable 60 MHz radar has been upgraded with a new digital data-proc essing and acquisition system and a new antenna construction enabling a fas t and low-cost installation on a Twin Otter aircraft. Augmented by a laser altimeter and kinematic global positioning system (GPS), the system has the capability of acquiring accurate data on location and ice-surface elevatio n, and adequate-quality data on ice thickness. The system has been applied successfully in mapping the Nioghalvfjerdsfjorden glacier, northeast Greenl and, in spite of the difficult conditions with melting water on the glacier surface. The measurements from the floating part of the glacier have been evaluated by comparison of radar data with laser-altimeter and in situ meas urements.