A new approach to lightweight radar altimeters

Test results and key principles are given for a radar altimeter designed for meteorological balloons. The instrument, which weighs 160 g and consumes 0.7 W, will fill a gap in meteorological, sensing using balloons-an area where pressure altitude was formerly the preveiling reference. The instrument is basically a delay-lock radar utilizing a superregenerative RF stage. Long-term absolute accuracy of ±10 m and short-term stability of better than- 2 m rms were measured at altitudes of 20 km.