# Source for emergency ROV/Sonar recovery pinger? **URL:** \ **Category:** Sonar and Acoustics\ **Created:** [November 28, 2022, 1:44am UTC](https://discuss.bluerobotics.com/t/source-for-emergency-rov-sonar-recovery-pinger/13274 "2022-11-28T01:44:08Z")\ **Posts on this page:** 1\ **Showing post:** 7
**Author:** ![EliotBR](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/eliotbr/32/6937_2.png) [@EliotBR](https://discuss.bluerobotics.com/u/EliotBR)\ **Post date:** [December 19, 2022, 12:03am UTC](https://discuss.bluerobotics.com/t/source-for-emergency-rov-sonar-recovery-pinger/13274/7 "2022-12-19T00:03:20Z")
> [@StrikeLines](#): > > 1. Lets say, “No larger than a can of spray paint.” I don’t think weight will be a factor. Ping sonar, additional circuitry and battery should be small enough. Fair enough. > [@StrikeLines](#): > > 1. I envision a solid state relay that closes and powers up the transmitter when external power is removed. I’d use a custom cable termination to “T” in where the tow cable connects to the sonar. That could also work 🙂 And yes, some form of T splice would likely be necessary to detect when power is available, unless you’re using AC power in which case you could also potentially measure it with current induced in a loop around the tow cable. > [@StrikeLines](#): > > They are the same as any other transducer, and are all tuned to a certain frequency. If we wanted to be universal, we could feed a “chirp” type frequency sweep from 50 to 400 kHz into the ping and just know that the signal will be “loudest” at 115 kHz. Thus a ~100kHz receiver transducer would be most effective. Fair enough, although there may be issues with trying to drive a narrow band transducer at any significant power level outside of its tuned range (it might crack, or build up excessive heat). > [@StrikeLines](#): > > Even better, is it possible to modify the code on the Ping sonar’s directly? That would make the most sense, but is not currently available. I’ve passed it on internally that you’re a +1 on us providing an open firmware source template for people to modify and compile. I believe that’s something we’re planning to do, but we haven’t yet had the time to make a version we can publicly share the source for. > [@StrikeLines](#): > > I got some specs from a commercial pinger. Do you know how Blue’s Ping sonar’s acoustic output compares to this? > > ULB-362C > Acoustic Output: **160.5dB re 1μPa @ 1m** Unfortunately we don’t currently have significant testing data to verify the absolute acoustic output of the Ping Sonar. We’ve [got a test setup](https://discuss.bluerobotics.com/t/ping-sensor-beam-profile/11662/5), but I believe our latest testing has been focused on our next iteration of the sonar, which should have more complete data when it launches. --- _[View the full topic](https://discuss.bluerobotics.com/t/source-for-emergency-rov-sonar-recovery-pinger/13274)._