MARPA?

[SimonGH]

I just installed a Halo 20+
I have a Vulcan 12R
Also in the system is a ZG100 and an FC40

MARPA requires a "rate stabilized heading sensor" putting out a signal at 20hz.

Simrad says the ZG100 is definitely not good enough, and they mention the RC42, but don't talk about the FC40...

Does the FC40 meet that requirement? From the tech specs it looks like it should...


from SIMRAD:
"Mini-automatic radar plotting aid (or MARPA) is a maritime radar feature for target tracking and collision avoidance. Targets must be manually selected, but are then tracked automatically, including range, bearing, target speed, target direction (course), CPA (closest point of approach), and TCPA (time of closest point of approach), safe or dangerous indication, and proximity alarm.
MARPA is a more basic form of ARPA (automatic radar plotting aid).

It is essential to use a heading sensor with an output speed of 20 Hz for MARPA to operate. Heading sensor needs to be a rate gyro stabilized compass or better. Point-1, GS25, and ZG100 GPS Compass is not intended for use with MARPA."

 

[zurk]

i have a HS60 DGPS. works fine with the halo 20+.
realistically it will take anything as long as you can show radar overlay on your charts. if it shows overlay you can do MARPA. you dont need a compass anything as long as you have something which can generate heading on the NMEA 2K bus.

 

[b393capt]

Furuno SCX20 is an even better choice.

 

[SimonGH]

If i'm going to buy something, I think i'd go with the Precision-9...

I'm not really understanding the benefit to a Satellite compass?

 

[SASSAFRASS]

Precious 9 works on the previous dome, 4G one before the Halo. Using with Simrad Evo9" display

 

[zurk]

If i'm going to buy something, I think i'd go with the Precision-9...

I'm not really understanding the benefit to a Satellite compass?

no magnetic interference. zero calibration required. always dead accurate.

 

[SimonGH]

As with anything there is a bit of a tradeoff. The satellite compass install manuals I looked at required an unobstructed view of the sky, and rigging and other sailboat stuff would definitely interfere with it... so ideally it goes at the top of the mast?

 

[Guillaume1066]

I was told by my B&G guys that the satellite compass is best for heading however the entire h5000 system was built with the precision 9 compass in mind. The heel pitch roll are used to correct the TWA and Tws. This lets the pilot drive much better. The downside it marpa is not crazy accurate. For me that was a good trade off since marpa is cool but not as important as a efficient and safe autopilot.

 

[2airishuman]

As with anything there is a bit of a tradeoff. The satellite compass install manuals I looked at required an unobstructed view of the sky, and rigging and other sailboat stuff would definitely interfere with it... so ideally it goes at the top of the mast?

Depends on the boat. The taffrail has a pretty good view unless there are davits, solar panels, a "stern arch" or other high-windage abominations. On cruising boats that rarely/never set a spinnaker the pulpit is a pretty good bet.

 

[kent_island_sailor]

Don't be surprised if MARPA/ARPA sucks on a sailboat, either direction. Either as a target or as the user of it, a boat running hard in a big sea and changing course rapidly is not what this was originally designed to do.