I'm happy to be the one to inform about the ongoing BR24Radar_pi development.
The BR24Radar plugin for Navico/Simrad/Lowrance BR24, 3G and 4G radar scanners is close to handle ARPA targets and transfer needed data into OpenCPN
It is a MARPA function in respect that the user has to right click a radar target on screen
and select a new menu item "Set ARPA Target". The radar plugin will now set the extent and position of the target's echo. While following the target its speed, course as well as distance and range to own ship is reported to OCPN and it will appear as an ARPA target following most of the logic for an AIS
target but with a different symbol.
Douwe is developer for the ARPA part of the plugin and source is available on GitHub, see below.
What we have tested so far are simulations using a recorded radar transmit session and a program feeding OCPN with navigational data for the same route
as the radar capture. All attached pictures are from such a simulation.
The ARPA implementation in OCPN was already very well prepared and only some minor adjustments are needed. Some already queuing as a pull request in GitHub and others are in a development phase.
Next steps are more testing, not less in reality but the winter season here prevents such activities.
Feel free to test the source for your own build, or if desired I can serve a dll file. See below.
The plugin will mainly work
in present OCPN 4.5 without mentioned changes although a lost
ARPA target deletion will not act as desired. I haven't tried in 4.4 but have no doubts.
Comments, Q's or thoughts? We'll try to answer all.
This test period has been very stimulating and many thanks to Douwe for this extension of the plugin where Kees and others has created a very good base for the ARPA implementation.
A Windows dll: https://dl.dropboxusercontent.com/u/...24radar_pi.dll
Test issues reporting: https://github.com/douwefokkema/marpa/issues
from the tests:
1. The process starts with a mouse over the radar target, right click and select "Set ARPA Target"
2. As soon the radar plugin has detected the target limits and position it reports to OCPN as status acquired - Amber symbol.
3. When course and speed are stable the status changes and the symbol is green with course and speed data.
4. The ARPA targets has the same functionality as an AIS
target, like CPA and TCPA info.
5. Also is the AIS target list applicable for ARPA targets.
6. The radar plugin use normal NMEA
messages to communicate to OCPN. ARPA targets can be seen on other screens as well.