From ARVP
Project Members
- Darrel Ross
- Chris Woloschuk
- Brodi Roberts
- James Rodway
Overview
The raw signal from the hydrophones is first sent through two programable MAX261 bandpass filters. The filtered signal is then sent to a dsPIC30, which time stamps each of the signals and sends them directly to the embedded computer.
Updates
Jan 2, 2009: In the end, we decided to go with the SensorTech SQ26-11 hydrophones. The total cost for each hydrophone, with a built in preamp, was about $200. They arrived before the winter break and testing will commence in the new year.
Feb 12, 2009: Below is a technical paper on passive sonar that was written by one of the members of our team, James Rodway. If you are working with they hydrophones, it is recommended that you read through it.
The hydrophone board has been built and is now in the testing stage.
Below is a link to a high level diagram showing how the signal is captured:
Below is the PCB of the 2009 Hydrophone Board
- The board measures 124.71 mm wide and 96.77 mm tall.
Depreciated Information
Hydrophone Comparison
Aquarian Audio Products H2a Hydrophone
| H2a Hydrophone | |
|---|---|
| Preamp? | Yes |
| Connection | 3.5mm Mic Jack |
| Weight | 265g |
| Dimensions | 40mm length x 25mm diameter |
| Price | $150 |
Cetacean Research C54XR Hydrophone
| C54XR Hydrophone | |
|---|---|
| Preamp? | Yes |
| Connection | Unknown |
| Weight | Not Listed |
| Dimensions | 130mm length x 25mm diameter |
| Price | Not Listed |
| Notes | Student / Non-profit discount available |
| TC4012 Hydrophone | |
|---|---|
| Preamp? | Extra ~ $1000 |
| Connection | Not Listed |
| Weight | 75g |
| Dimensions | 63mm length x 9.5mm diameter |
| Price | ~ $1300 |
| SQ01 Hydrophone | |
|---|---|
| Preamp? | Extra ~ $? |
| Connection | Not Listed |
| Weight | 75g |
| Dimensions | 95.2mm length x 30.7mm diameter |
| Price | ~ $450 |
The original design used LM567 tone decoders to detect the signal and trigger a line to the MCU 5V high, but during inital testing, it was discovered that interference could cause the LM567s to fail to trigger. It was due to this that the team decided to send the filtered signal directly to the embedded computer for processing. Further refinements on the system decided to have the filtered signal connected directly to a dsPIC30F which could time-stamp the arrival of the signals and forward the values to the embedded computer, reducing the workload of the computer.
