Ocean Sonics icListen HF and icListen AF hydrophones contain accelerometers which record acceleration in X, Y, and Z axes, and magnetometers which record magnetic field in X, Y, and Z axes.
Acceleration and magnetic data are recorded to .acc files at 1 sec intervals. Samples are also written to ancillary data at the data rating for the device (often 1 sample per minute), and are available independently as scalar data products or via Plotting Utility.
These values can be used to monitor changes in the orientation of the instrument once it has been deployed. icListen HF User Guide 2018
Oceans 3.0 API filter: dataProductCode=HACC
Depending on the 'HardwareVersion' attribute of the icListen Hydrophone that can be found under the Additional Attribute tab of the Device Detail URL, the vertical axis varies as follows and the details can be found in this Ocean Sonics document
| Hardware Version | Vertical Axis |
|---|---|
| 4 | -Y |
| 6 | No Orientation sensors |
| 7 | +X |
| 8 | -X |
Note that the diagram has the hydrophone element drawn as laid horizontally, but in our deployments the element is deployed pointing with the tip upwards.
There are no options for this data product.
Raw acceleration and magnetic data are combined in a single file format ACC.
An example ACC file:
ICLISTENAF2556_20191009T000000.000Z.acc
ACC/.acc files are in the format:
20191009T000003.363Z -451,-883,-129,65,391,-654 20191009T000004.152Z -452,-882,-132,66,393,-649 20191009T000005.156Z -450,-881,-132,61,405,-643 20191009T000006.157Z -450,-880,-130,59,398,-635 20191009T000007.157Z -449,-880,-130,64,392,-647 20191009T000008.157Z -449,-880,-130,64,392,-647 20191009T000009.159Z -453,-882,-135,64,393,-655 20191009T000010.157Z -451,-882,-133,61,401,-644 20191009T000011.160Z -450,-885,-132,63,392,-651 20191009T000012.157Z -451,-877,-126,64,391,-652 ... |
Where:
Oceans 3.0 API filter: extension=acc