New Tools for Tracking Small Invertebrates Using Harmonic Radar

We introduce two novel radar systems for tracking small invertebrates, such as insects, using a harmonic radar operating around <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$9 \text{GHz} / 18 \text{GHz}$</tex>. The first is a scanning radar that continuously measures the range and angle of tagged targets to study their movement patterns. The second is a handheld radar designed for fieldworkers to periodically re-locate tagged targets with visual and audio prompts. Preliminary field results show promising capabilities, with the scanning radar detecting tags up to 130 m, and sub- 1 m localisation accuracy (at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$20-30 ~\mathrm{m}$</tex> range). The handheld radar could function effectively within 60 m under ideal conditions. However, challenges remain, such as the dependence on the tag orientation, occlusion by vegetation/leaf litter, affixing tags, and the influence of nearby objects (including the target body). Future work will address these issues, in addition to expanding system capabilities using mobile platforms and remote monitoring using cloud processing.