Driver to decode multibeam data from an Imagenex (http://www.imagenex.com/) Model 965 profiler system outputting the "96P" format suitable for 360 degree scan output.
The system uses 4 x 90 degree DeltaT sonars to generate the 360 degree image (there is no mechanical tilting involved). This system is capable of delivering 360, 7020 or 1440 beam points per scan.
Beam data is broadcast via network UDP packets by the topside processing application. QINSy driver will receive and decode the beam data and transfer it into the QINSy system.
Driver can currently not be used to decode any auxiliary data like position and motion but only multibeam data.
At the time of writing this document (June 2013) the system is still in its prototype stage.
Driver decodes raw range and angles and beam intensity from the data. In contrary to old mechanical profilers all the beams of one head are transmitted at the same time so internally the decoded data is the same as an 'ordinary' multibeam system. Beam data does not contain any additional info beside range, beam angle and intensity. Number of beams are user selectable: 360, 720 or 1440 per head at a resolution of 1, 0.5 or 0.25 degrees respectively. Note that the beam angles are inverted in the driver to convert from Imagenex convention (positive clockwise) to QINSy convention (positive counter clockwise). Note that in QINSy a beam angle of 0 degrees is considered straight down for an ordinary multibeam, but the same principle applies for a system like this.
The Device list is currently not used, driver is only used for decoding the multibeam data.
To prevent loss of Multibeam UDP packets it is recommended to interface directly between topside processor and QINSy with a network cross cable, not through a hub or switch.
The Imagenex software that will be run on the topside computer should be set up to broadcast UDP packets to the QINSy computer where the driver will receive and decode these packets. In the Imagenex software the UDP output must be enabled via the menu "Data Output". Select "P96 (Point Output)" and the IP Address can be set at 127.0.0.1 if QINSy is running on the same PC as the Imagenex program or on the IP Address of the QINSy computer if running separately. The number of beams can be selected in the Imagenex software, either 360/720/1440.
Driver can decode the ping time reported by the system (PPS drivers.io option) or use the time of arrival of the UDP packet. The latter may not be reliable because of network latencies. The multibeam does not report a latency value yet in its output telegrams, so if timing will be accurate remains to be seen. Make sure that if the ping time reported by the multibeam is used (PPS driver.io option) that the topside processor's clock is synchronized with the QINSy clock by means of PPS otherwise time stamping will be totally unreliable. Timestamp will only be used if QINSy itself is using a PPS system for time synchronization.
Add new multibeam system to the template, select Driver "Imagenex 965 Profiler" . Set port number to 4040, this is the default UDP output port of the Imagenex software.
If you would like to use the timetag as reported in the packet and the profiler is properly time synchronized then select Driver "Imagenex 965 Profiler (UTC)"
The port number is usually 4040. The maximum number of beams should be set to 1440.
If proper roll data was fed into the sonar and its output is roll stabilized then the "Unit is roll stabilized" can be checked. In this case QINSy will not apply a roll correction to the beams.
For more information refer to Imagenex website: http://www.imagenex.com/
Drivers IO Notes
Command line parameter description for "drivers.io" file.
PPS: Use timestamp as reported by the profiler. If this option is not used (default) then UDP arrival time is used.
Make sure that if you use the PPS option that clocks on both PCs (Imagenex topside Processor and QINSy) are synchronized to UTC time.