Time Expansion Bat Detector Circuit

A 5 ms bat call at 40 khz would sound like a 50 ms call at 4 khz.

Time expansion bat detector circuit.

Time expansion bat detectors. Frequency divider heterodyne time expansion dsp digital signal processor. Time expansion detectors work by storing the call in their internal memory and then replaying it back 10 x slower thus lowering the frequency. The advantage of this system is that all frequency information is retained for later analysis.

Typically the sampling rate ratios can be varied from 1 10 to 1 32. A bat detector is an electronic listening device that will allow us to hear the bat chirps and buzzes. Heterodyne detectors are great for beginners but professional bat workers will also turn to the more technologically advanced models which allow extensive recording and. They detect all frequencies across the frequency range within which bats are likely to be calling.

Chris eve s bat detector circuit view experiment. Bat sounds are heard at 1 10th the frequency and 10 times the duration so no frequency information is lost as is the case with heterodyning or frequency division. The output is audible on a loudspeaker or headphones. Hand held or passive and type of technology heterodyne fixed frequency time expansion or full spectrum.

There are several types of bat detectors being used by bat listeners. They work by digitally recording a brief snatch of bat sound usually about one second and replaying it at a slower rate usually ten times slower. Time expansion te detectors work by digitising the bat calls at a high sampling rate using an analog to digital converter and storing the digitised signal in an on board memory. Time expansion te detectors are broadband detectors i e.

Bat detector choices are influenced by factors such as your experience the mode of operation that you want e g.