Which radar will perform best with Opencpn?

[Dockhead]

Originally Posted by Bill O

I wasn't disagreeing w/you, just wanted to make it clear for everyone that you possibly need the extra hardware and then configuring (e.g. signalk) get them to work. Yes there are many examples of the hardware in the manual link provided previously.This can be a pain at times and shouldn't be matter of factly glossed over as easy (full disclosure).
We do our own work and can compile from source, so we know it can be frustrating at times.

The convertors I've used are plug and play.

Likewise the 0183 datastream from the plotter works any old way -- 0183 to USB adapter, wifi, ethernet, with zero fiddling.


The only task is setting up OpenCPN data source correctly (which can be a minor fiddle). One other minor issue I have is that the IP address of the plotter which does the conversion, changes sometimes, so I have to set up a new connection from time to time, but once you've done it a few times, it's no big deal.

SignalK is fiddly, but POWERFUL.

I think this part of the process is fairly easy, although I do understand that people who have not even the kind of very superficial knowledge of networking I have, might be daunted by the OpenCPN setup.

[merrimac]

Originally Posted by Tupaia

The Halo and 3G/4G models use slightly different tech with Halo using pulse compression giving very slightly better squall definition. Neither are as good at this as a full "old fashioned" pulse radar.

Now that I've been forced into quibble mode, let me add a few words to this as well.


The BR24/3G/4G were the original disruptors over 10 years ago which used FMCW (Frequency Modulated Continuous Wave) which did away with a magnetron. This meant no startup time, but the electronics available at the time could not handle big pulses so to increase the amount of energy they used a continuous wave instead of a pulse. According to the FCC a BR24 only puts out 100mW ( https://fccid.io/RAYBR24 ) and a 3G/4G is 200mW ( https://fccid.io/RAY3G4G ) The up/downside of this tech is now well known: superb at short range, weak at (very) long range and at detecting weather, although 4G is better than BR24 + 3G.


The HALO radars still use a fully silicon based approach, but using higher power FETs they are able to (just) send out enough energy so that they can use a shaped pulse, with exact control over the length, shape and frequency of the pulse. The HALO20 puts out nearly 20W and the HALO24 puts out 25W during the pulse, see https://fccid.io/RAYHALO . The advantage over a magnetron is that it doesn't wear out and that the pulse is finely controlled, but the peak of the pulse is still orders of magnitude weaker which is compensated for by shaping amplitude and frequency. The magnetron is more like an internal combustion engine: you insert energy and hope that the pulse comes out the right way. You cannot use feedback loops or so to control it. It is a big whammer of a pulse though: 2 - 25 KW, although just a few milliseconds for each pulse. This is why a magnetron at some point wears out: the gap slightly widens, and the pulse, over time, shifts in frequency so that (a) you are creating noise in the wrong HF band and (b) the receiver can't receive it as well.


This new tech is now used by all manufacturers -- Furuno, Ray, Garmin, Navico -- in all their new lower power radars, with magnetrons pushed to higher powers (if at all.)


One advantage of the shaped pulse is that it can include a small frequency change allowing for better range detection, and the knowledge about the exact frequency can be used to compare the received energy pulse to the sent pulse, and any frequency shift is caused by the Doppler effect. This provides the "knowledge" whether a target is moving away or towards the scanner. For the HALO radars we know how to get this data out and paint the "doppler detected" targets in a different color. What we don't do yet (what the Furuno radar + MFD combo apparently can) is to automatically convert any doppler target into an ARPA target.


And having sailed the Atlantic with HALO, in my humble opinion HALO is much better at detecting squalls than FMCW, and does not leave me wanting for something better.

[Bill O]

Originally Posted by merrimac

Contra quibble, you are referring to the OpenCPN wiki which is not accessible to us plugin writers and are outdated compared to the plugin wiki, see https://github.com/opencpn-radar-pi/...lation-(Navico)


If you call crimping on a RJ45 to save a few bucks "reconfiguring" then maybe you shouldn't be doing this at all. Or you can read the proper manual page and buy a Navico RJ45 to Yellow converter cable.

For your link, yes you are correct, you just need to crimp on the end if needed.

Not that you have anything to do w/it, but it would be nice to have updated info in the manual or all in one place so people can find it easily.

[Douwe Fokkema]

Originally Posted by merrimac

For the HALO radars we know how to get this data out and paint the "doppler detected" targets in a different color. What we don't do yet (what the Furuno radar + MFD combo apparently can) is to automatically convert any doppler target into an ARPA target.

The feature Kees mentions here is further discussed on: https://www.cruisersforum.com/forums...=1#post3316552

Douwe Fokkema

[SoonerSailor]

Originally Posted by Tupaia

Although both 3G/4G and Halo 20 have running consumption of 18-20W the Hal has roughly twice the standby consumption 6.5W vs 2.9W albeit that both are tiny.

I've measured standby on the HALO24 to be .250 A at 14 V

Chip

[Twilight-lat]

Hi,
I also have the same question.
Just read all the posts in this thread.

"It's not rocket science" errr atm yes it is.

I need layman terms please, I am software geeky but not marine hardware.

We have to buy a radar asap to send to the mast builder.
Expensive gizmo to be buying the wrong one.


Navico Halo, there are a number of choices.
"with the dual-range Navico radars counting as two radars" (from github page)
Does this also means it uses twice the power?

Running pi 4gb. pi is the chart plotter. So one ethernet port. Do not have a router.


from the github page https://github.com/opencpn-radar-pi/...n-%28Navico%29

The radar get installed on the mast, cable comes down into boat.
It doesn't seem like it's just a matter of running the cable to the Ethernet port on the pi.

The Navico radars are very easy to use with OpenCPN. All you need is a wired Ethernet connection."

Then this:
"We recommend always using an ethernet switch in this setup to provide further electrical isolation between the scanner and the computer -- this makes your computer safer in case of lightning. If you connect the computer directly to the radar scanner you have a higher chance of lightning ruining your computer."

Lightning is a concern, so an ethernet switch, I guess is a must.
Is a 12v one ok?

Our cat is electric, so power consumption is a major consideration.
It seems radars consume a lot of power, even in standby mode.
Is this correct?

Will this simrad Halo 20 be compatible?
Is is on special atm

https://chsmith.com.au/Products/Simr...hoCyPQQAvD_BwE

If not another suggestion please.

[Hakan]

Twilight...
A Halo20 is very fine. See the post before yours for power consumption. These types use very little power. And it's also easy to shut it completely of since there's no waiting time for next start up. There's no "power up" time period as for a "normal" X-band radar.

Lightning can be a concern as for all electronic devices. I'd say it's up to your trust and risk assessment. But a switch is not bad at all. A small one with e.g. 5 ports and 12 supply is good. Then you can feed it direct from a fuse without a power converter.
But apart from the lightning issue you can also very well connect your radar IP connection direct to the RPi4. The extra lightning risk, apart from the radar itself, is for the RPi4. And you may have another for backup reasons already? (And a dongle for O-Charts oeSENC charts if that's your choice.)

If a Halo or 4G takes considerable more power when in dual mode I don't know but I don't think so. Chip or anyone else may have tested that. (I've a 3G myself.)

[Twilight-lat]

Originally Posted by Hakan

(And a dongle for O-Charts oeSENC charts if that's your choice.)

If a Halo or 4G takes considerable more power when in dual mode I don't know but I don't think so. Chip or anyone else may have tested that. (I've a 3G myself.)

I guess, if not tested, I will and share the results.

Thank you so much for your quick reply, I understood your answers clearly.
I'm good to go ahead now with the radar. Phew....

There will be 3 raspberry pi's. One to muck with, program/test etc., and one in a farraday cage with a couple of spare backup sd cards.
Did not know about the dongle for multiple devices. That's a little annoying. Another thing to have to plugin and risk losing, so this means we'll have to buy 2 (one for the farraday cage).


Is there a list for compatible autopilots (hydraulic) like there is for radars?
We already have hydrive rams.

[Hakan]

re: The dongle.
Talking O-Charts.org and oeSENC charts the dongle is fine for rescue and for use of the charts on every other PC. Onboard or at home. For the NAV-PC you don't normally need it. There are two copies, slots, for every chart license. I use one slot for the Nav-PC to run without the dongle and one slot for the dongle.
For a RPi that's essential since a SD card failure is a the most known cause for a breakdown. Than the chart slot is broken.
So no need for daily dongle handling. Keep it in the cage.

No list of autopilots. The general rule is its control system shall understand NMEA0183 to work with OCPN directly. For some NMEA2000 APs there are plugins to OCPN but you still need a N2K-NMEA0183 converter. A wind vane is most power saving though. :-)
Good luck

[Twilight-lat]

Originally Posted by Hakan

No list of autopilots. The general rule is its control system shall understand NMEA0183 to work with OCPN directly. For some NMEA2000 APs there are plugins to OCPN but you still need a N2K-NMEA0183 converter. A wind vane is most power saving though. :-)
Good luck

Thank you again. I'll look for nmea0183.

I looked into getting a windvane for our multihull.
Because of the power saving.
I contacted Hydrovane. last year. Never got a response.
I've only seen them in use on mono's in videos.
and this picture on a multihull. [from Hydrovane's site]
I was unable to find out if it was a possibility with our cat.

https://hydrovane.com/wp-content/upl...7-Red-Vane.jpg

[Hakan]

Now where out of topic but one last:
https://www.cruisersforum.com/forums...an-201651.html

[zigzag930]

Is there any chance that Furuno, might be supported by radar_pi at this time? I see the last post was some time ago.

I would be willing to work with a developer on this if that would be of any help.

Currently using MFD12, DRS25a and Hub101, so ethernet connection is easy. Packet display of radar info is another story.

Thanks
J

Originally Posted by Hakan

No you've got it to a mix.
All Navico broadband types, (BR24) 3G, 4G and Halo, are supported by radar_pi and OCPN.
The 3G is then a Navico and not a Furuno and no Furuno is supported by radar_pi.
Read more here about radar_pi and supported types: https://github.com/opencpn-radar-pi/radar_pi/wiki

There are also advises about connections.
Håkan

[jordanbigel]

Originally Posted by zigzag930

Is there any chance that Furuno, might be supported by radar_pi at this time? I see the last post was some time ago.

I would be willing to work with a developer on this if that would be of any help.

Currently using MFD12, DRS25a and Hub101, so ethernet connection is easy. Packet display of radar info is another story.

Thanks
J

I tried to figure out how to modify the radar plugin to work with my furuno DRS4DNXT and didn't get past the starting line (I watched the traffic from the furuno on Wireshark) got the plugin to build and run, but didn't get any further. That was like 2 years ago...

The learning curve is steep and my day job is still a huge demand on my time, sadly. Plus I'm busy every weekend working on the boat, etc., etc. - </lame excuses>.

[zigzag930]

I am guessing the you tried using the Garmin and other settings, but none worked?

I wonder if the radar packets use some un-obtainable proprietary coding? Clearly if Timezero can display the radar, then it is possible (with knowledge) to do this in the OpenCPN plugin.

I'd be willing to devote a bunch of time to this if anyone could assist in how to approach the project.

J

Originally Posted by jordanbigel

I tried to figure out how to modify the radar plugin to work with my furuno DRS4DNXT and didn't get past the starting line (I watched the traffic from the furuno on Wireshark) got the plugin to build and run, but didn't get any further. That was like 2 years ago...

The learning curve is steep and my day job is still a huge demand on my time, sadly. Plus I'm busy every weekend working on the boat, etc., etc. - </lame excuses>.

[catsketcher]

I have read and re-read the forums here and elsewhere about radar. I would like to cruise to Vanuatu in 2024. I have done a heap (about 8 years fulltime) of coastal cruising and would like a radar for
- watching squalls at night (I sail a cat and would like to reef for the gusts)
- seeing ships and non AIS targets at night
- helping keep watch day and night
- helping me get the lay of the land at night.

I have coastal cruised for 40 years with few electronics, I like my GPS and OpenCPN is a great. My little dAISy was great on our Hobart trip and I can't live without a depth sounder, but no wind, and no plotter. (OpenCPN on the laptop is great - on a cat I can see it when it sits on the table inside, from the helm and inside), and I am putting together a PyPilot autopilot.

I am now richer than when I built our boat, and would like to have an extra set of eyes for sailing shorthanded (I always sail shorthanded - 1 or 2 up). So radar has piqued my interest. I have been looking for secondhand 4G setups and after reading the forum I have been wondering - should I bother with secondhand 4G or just spend the extra and go Halo?

I was thinking of the Halo 20+. It has doppler (which might be nice) and other stuff. I can get one for $2700 AUS. 4G radars (secondhand) are going for about $1000. For that I get no warranty and an older radar which may or may not work (I can't test them). I have the money to buy either, I just don't like spending money on electronics, as they always get old. I end up spending plenty on the boat anyway, but when the night comes down I get a little more uneasy than in the day and I think radar may help me feel a little better about what is out there. I feel the weight of responsibility quite heavily in the pitch black.

I can make my own mast mount and installed my own rig (and built my own boat) so I should be fine for fitting the thing. My son is doing the Raspberry Pi side of things with PyPilot, a Davis wind instrument, (going to the dark side) Openplotter and the radar. We may have a few Pis in the end.

Is the extra money for the Halo20+ worth it? Or is the 4G fine for what I want? I can make up my own mind but I would be interested in what people who know more than me about radars would do in my case.

My cat is a 38ft performance (ish) cat. The radar will be about 5 metres up the mast.

cheers

Phil