Laboratory for
Climatology and Remote Sensing

Abstract:

Systematic, practicable, and global solutions are required for insect monitoring to address species decline and pest management concerns. Compact frequency-modulated continuous-wave (FMCW) radar can facilitate these processes. In this work, we evaluate a 60 GHz low-range FMCW radar device for its applicability to insect monitoring. Initial tests showed that radar parameters should be carefully selected. We defined optimal radar configuration during the first experiment and developed a methodology for individual target observation. In the second experiment, we tried various individual-insect targets, including small ones. The third experiment was devoted to mass-insect-target detection. All experiments were intentionally conducted in very uncertain conditions to make them closer to a real field situation. A novel parameter, the Sum of Sequential Absolute Magnitude Differences (SSAMD), has been proposed for uncertainty reduction and noisy data processing. SSAMD enables insect target presence detection and biomass estimation. We have defined ranges of SSAMD for distinguishing noise, insects, and other larger targets (e.g., bats, birds, or other larger objects). We have provided evidence of the high correlation between insect numbers and the average of SSAMD values proving the biomass estimation possibility. This work confirms that such radar devices can be used for insect monitoring. We plan to use the evaluated system assembled with a light trap for real fieldwork in the future.

Abstract:

Drastic declines in insect populations are a vital concern worldwide. Despite widespread insect monitoring, the significant gaps in the literature must be addressed. Future monitoring techniques must be systematic and global. Advanced technologies and computer solutions are needed. We provide here a review of relevant works to show the high potential for solving the aforementioned problems. Major historical and modern methods of insect monitoring are considered. All major radar solutions are carefully reviewed. Insect monitoring with radar is a well established technique, but it is still a fast-growing topic. The paper provides an updated classification of insect radar sets. Three main groups of insect radar solutions are distinguished: scanning, vertical-looking, and harmonic. Pulsed radar sets are utilized for all three groups, while frequency-modulated continuous-wave (FMCW) systems are applied only for vertical-looking and harmonic insect radar solutions. This work proves the high potential of radar entomology based on the growing research interest, along with the emerging novel setups, compact devices, and data processing approaches. The review exposes promising insect monitoring solutions using compact radar instruments. The proposed compact and resource-effective setups can be very beneficial for systematic insect monitoring.