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A high-resolution and light-weight impulse radar has been developed for short range detection of subsurface objects and interfaces. This radar can be used as a hand-held instrument or it can be mounted on a vehicle. The new radar is optimized for fairly short measuring distances (about 2 m) with good accuracy (few centimetres). Modern data processing and display technology has been used in order to reduce the power consumption and physical size of the instrument. The radar has proved to be very useful in ice thickness measurements. For safety reasons it is essential to measure continuous profiles of the ice thickness and to find the weak spots in order to avoid vehicles to sink through the ice. The impulse radar measures a continuous profile of ice thickness without any conventional methods, e.g. by drilling holes in ice and measuring the thickness with a scale stick.

A newly developed microwave snow sensor, snow fork, measures the dielectric properties of snow in the 500 to 1000 MHz frequency range. The relation between the dielectric and physical properties is used to calculate the density and free water content of snow. The instrument is portable and battery operated. In March 1988, field tests were conducted to compare the fork with conventional measuring devices for the analysis of 13 snow profiles. In general, the curves of snow layer properties based on snow fork and comparative measurements were similar in shape but the fork results produced a more detailed profile. There was some systematic error in density values. The fork was easy and fast to handle and operate on the field. After further development the snow fork can be a useful tool in collecting data of snow properties for trafficability analysis.