from 28 June 2015 to 3 July 2015 (Africa/Johannesburg)
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SAIP2015 Proceeding published on 17 July 2016
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Development of kHz applied optical remote sensing for atmospheric insect monitoring applications

Presented by Mr. Alem GEBRU on 1 Jul 2015 from 15:20 to 15:40
Type: Oral Presentation
Session: Photonics
Track: Track C - Photonics


Alem Gebru1, 2, Erich Rohwer1, Pieter Neethling1, and Mikkel Brydegaard1, 2 1. Stellenbosch University 2. Lund University Effective ways of monitoring insect activities in situ is crucial for entomologists. Such studies have in the past relied more on manual analysis using traps and sweep nets [1-3]. However, it is difficult to monitor fast interaction kinetics and huge numbers simultaneously, which leads us to look for other ways of studying the activity of atmospheric fauna. We have developed a kHz applied optical remote sensing system for monitoring atmospheric insect , which is capable of determining wing-beat frequency, flight directions, optical cross-section and range. This is a comprehensive system, which works both in active and passive modes. The passive mode is based on a remote dark field spectroscopy technique. We use sun light as an illumination source, a dual band detector (silicon (Si) and indium gallium arsenide (InGaAs)) to study the iridescence features, silicon quadrant detector to determine flight direction and a spectrometer for colour information. We have used a 25cm diameter F/4 receiving telescope and dark termination box to reduce the back ground signal. In the active mode, which is continuous wave light detection and ranging (CW-LIDAR) technique, we use a 3W, 808nm laser transmitted by F/5 refractor telescope and the same receiving telescope as in the dark field experiments. In our previous work, we were able to determine wing-beat frequency, irradiances features and flight direction of insects remotely [4, 5].This technique enables us to track fast events and huge numbers.






Prof Erich Rohwer,, Stellenbosch University





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