Array Accelerometer Readout
Array Accelerometer
This module had now been replaced by the new Analog Array Sensors module.
We recommend that you switch to the newer module.
Overview
The Array Accelerometer module can be used to measure the pitch and roll of a hydrophone array.
With simple line arrays, knowing the precise orientation of the array is probably not necessary. However as more users move towards using multi-channel, multi-dimensional hydrophone arrays in order to determine animal locations in three dimensions, knowing the orientation of array sections becomes increasingly important.
Three axis accelerometers are readily available at low cost (most of us probably have one in our phone and another in our camera). The PAMGuard Array Accelerometer module has been designed to specifically to work with the Analog Devices ADXL335. Users who don’t wish to, or don’t have the capability to incorporate surface mount IC’s into their hydrophone designs can use the EVAL-ADXL335Z Evaluation Kit. These are readily available from electronic component suppliers worldwide.
The system currently only works with MeasurementComputing data acquisition cards (www.mccdaq.com) but may be extended to support other devices in the future. It is possible to use the same MeasurementComputing card with the Array Accelerometer module and the Hydrophone Depth Module
Pith and roll information is passed to the hydrophone array manager which makes it available to other PAMGuard modules as required.
hydrophone array configuration dialog.
A small side panel shows a graph of recent pitch and roll history.
Database output
Both the raw voltage data and the calculated pitch and roll are written to the database. It is therefore possible to recalculate pitch and roll off-line if sensors are re-calibrated at any point. (PAMGuard will not currently do this for you - you’ll have to work it out for yourself using your own software).