Time Expansion Bat Detector Circuit

The output is audible on a loudspeaker or headphones.

Time expansion bat detector circuit.

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. Frequency divider heterodyne time expansion dsp digital signal processor. Time expansion te detectors are broadband detectors i e. Time expansion te detectors work by digitising the bat calls at a high sampling rate and replaying them at a lower sampling rate immediately afterwards.

The advantage of this system is that all frequency information is retained for later analysis. Chris eve s bat detector circuit view experiment. There are several types of bat detectors being used by bat listeners. Typically the sampling rate ratios can be varied from 1 10 to 1 32.

Heterodyne detectors are great for beginners but professional bat workers will also turn to the more technologically advanced models which allow extensive recording and. Time expansion bat detectors. Time expansion detectors work by storing the call in their internal memory and then replaying it back 10 x slower thus lowering the frequency. 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.

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. Hand held or passive and type of technology heterodyne fixed frequency time expansion or full spectrum. They detect all frequencies across the frequency range within which bats are likely to be calling. Te detectors are real time devices in that they can be monitored at the time of recording but there is an inevitable delay while the high speed sampled extract is.

A time expansion detector needs some kind of memory to store the bat call.