A portable radio-acoustic sounding system for temperature profiling within the boundary layer

The development of an outdoor portable radio-acoustic sounding system is presented using a novel composite antenna. A parabolic antenna is coupled with a centrally located acoustic emitter which facilitates monostatic operation. The radar operates within the 2.4 GHZ ISM bandwidth at 2.45 GHz, corresponding to a typical acoustic frequency of 5.6 KHz (at 15 °C). Modeling and simulation was carried out to provide a basis for development of the prototype, yielding an expected return power of -94.5 dBm at the desired range of 100 m. The performance of individual Doppler radar and signal processing subsystems has been validated using a highly-reflective metal target. Initial prototype testing was conducted using the feed antenna placed alongside the speaker in order to generate a response consistent with Bragg matching; this has revealed microphonic behavior, rendering temperature immeasurable at close range. Further work is to be done to configure the parabolic antenna so it can be used in testing; this is expected to improve the signal to noise ratio by 25.8 dB, improving the likelihood of obtaining measurable backscatter.