Needing electronic compass for Radar (AIS)

[chouliha]

Hi Guys

I recently installed a Furuno 1815 radar. The product info states it will display GPS data and AIS information. BUT the manual never said I needed to supply compass information as well. After a number of emails with the Furuno tech I was told I needed heading info.

Furuno states: It will need a GPS input (GP32), AIS data (Vesper) and a Heading Data input (Heading Sensor or compass). Otherwise, targets will not show up. Heading input (HDM, HDT, or HDG)

I can supply GPS using the Furuno GP32 and AIS data from Vesper watchmate.

Does anyone know of an inexpensive compass that I could receive NMEA signal from? Needing HDM,HDT or HDG sentences.

Thanks

Chuck

[clownfishsydney]

Surely it means compass heading from GPS.

[IslandHopper]

I would check with Furuno and see if their PG-500 or PG-700 Heading sensors are suitable, if not then ask what is? they should have the correct answer....

http://www.furuno.com/en/products/compass/PG-500

http://www.furuno.com/en/products/compass/PG-700

It does mention on the Furuno website the need of a heading sensor...

8.4" COLOR LCD RADAR MODEL1815 | Marine Radar | Products | FURUNO

Display Mode

Head-up, Course-up*, North-up*, True view, True motion**

* Heading data required

** Heading data and position data required

@clownfishsydney, GPS alone will not give a heading.

[Opie91]

As IslandHopper said the gps alone will not supply the information.

The GPS has no idea where the bow is pointed it only knows the COG. The radar needs to know where the bow is pointed as it has no other reference to work off of.

[Suijin]

You need a heading sensor (i.e. electronic compass) for MARPA/ARPA to work on your radar. I would suggest that if you want that functionality that you buy a decent compass, ideally one that is confirmed to work well with your Furuno. If the updates are not rapid the output can be shaky and borderline unusable.

[Bleemus]

Heading data should only be needed for MARPA/ARPA right?

[Snore]

On my personal boat I get heading (vs GPS COG) from my autopilot.

[alctel]

Use this

Simrad GS25 GPS Antenna | SIMRAD

This is the simrad flavour, but Lowrance/B&G do a version as well (all owned by the same company and basically identical)

I belive most people should have one of these anyway - for the price (a couple hundred dollars) it's amazing as:

- nmea2000
- its a powerful GPS reciever
- it does GLONASS
- also WAAS
- has a heading indicator/roll indicator built in as well (which is what you are looking for). Now, it's not as good as a dedicated electronic compass and I wouldn't use it for autopilot stuff probably but to get a radar to display it's fine and makes a great backup to a primary electronic compass. I used it to get my radar to display MARPA targets before I got an Airmar H2183 compass for a autopilot system.

[bauer965]

The Simrad GS25 isn't a true compass, even though it manufacturers a HDG sentence. Even Simrad admits to it, to wit: "Please note this product is not suitable for use with MARPA or autopilot systems". The accuracy and quality of the heading from these type of fake compasses (does the unit also pour you a latte?) isn't something you want to send to other equipment for navigational calculations.

The Digital Yacht DSC100 is a fine unit at a fair price. I recommend it for those not needing to step up to the very expensive true dual-antenna GPS Compass.

[Paul L]

There's a used Furuno PG-500 on EBay now for $199.

[alctel]

Originally Posted by bauer965

The Simrad GS25 isn't a true compass, even though it manufacturers a HDG sentence. Even Simrad admits to it, to wit: "Please note this product is not suitable for use with MARPA or autopilot systems". The accuracy and quality of the heading from these type of fake compasses (does the unit also pour you a latte?) isn't something you want to send to other equipment for navigational calculations.

The Digital Yacht DSC100 is a fine unit at a fair price. I recommend it for those not needing to step up to the very expensive true dual-antenna GPS Compass.

It's totally fine for MARPA - I used it for that for almost two years. As I said, I wouldn't recommend it for a primary unit for autopilot. What makes it fake?

[roland stockham]

A heading sensor is also needed to stabilize the radar. Don't know your unit but radar works most effectively if it monitors heading changes and compensates the display to give 'course up'. Without this the radar picture swings around with every small change in heading and makes it very difficult to see what is going on.
Do you have an autopilot? If so it should have a min 10hz heading sensor. If you can link that into the network you should then have the required data available to the radar.

[captmikem]

Check to see if your autopilot uses a Fluxgate compass, if not you can buy a new or used one pretty cheap. Quick internet search shows a Raymarine Fluxgate for $161.

M

[sailon46]

I am lost with the original post. I have a Garmin 740s still working brilliantly and a Garmin HD18 radar connected to it. No compass needed since it works off the 740s. This Furuno stuff I don't understand, anybody willing to enlighten me.
Thanx,
Ernie on the Mary Jane

[roland stockham]

Originally Posted by captmikem

Check to see if your autopilot uses a Fluxgate compass, if not you can buy a new or used one pretty cheap. Quick internet search shows a Raymarine Fluxgate for $161.

M

These do work pretty well but I think need to be linked to the autopilot to get NMEA output. The one that give direct NMEA output are more expensive and usually have a compass readout or display head.