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Operation porcupine

dwblair edited this page Aug 16, 2012 · 43 revisions

"(Pulses-Of-Remote-Camera-Use-Ping-If-Not-Enduring)"

  • Related discussion re: general technique here
  • Discussion re: using walkie-talkies here

Links / Resources

Battery monitoring

Loud noise generation

Research Notes

August 12, 2012

Purchase of Motorola FV300 at Radio Shack. $20 for walkie talkies, $19 for headset.

August 15, 2012

Test of line-of-sight audio transmission range for the Motorola FV300.

Today we took two FV300s out onto the Amherst High School field, at a line-of-sight distance of around 1300 feet. We had one researcher hold down the push-to-talk (PTT) button and simultaneously trigger the camera on an iPhone, and determined with the researcher 1300 feet away could discern the clicks. No wind to speak of today.

We tried several positions of iPhone, and several volumes for the "click" sound. Here is a video of one such test, where the phone was placed right up against the FV300 mic.

Our main conclusions were:

  • When the handset was held right up against the phone ("position 1" below), all volume settings generated clicks that were audible at 1300 feet;

  • When the handset was held a hand's distance away from the FV300 ("position 2" below) and maximum volume was used, clicks could be heard at 1300 feet;

  • Any further away from the phone, clicks weren't really discernible at maximum volume.

  • Approximately 1300 feet, line-of-sight, between the walkie-talkies. See the map on Google Maps.

The field.

The experimentalist: Marcelo Dias.

Position 1 (see video here. Result: All iPhone camera shutter clicks, at all volume settings, were audible.

Position 2. Result: iPhone camera shutter clicks were audible only at maximum volume.

Position 3. Result: No shutter clicks were audible.

Position 4. Result: No shutter clicks were audible.