Opensource and Furuno radar

[wstu]

I am researching whether I can hookup my Furuno 1623 radar wirelessly to Opensource on my Ipad. My radar has the ability to output/input NMEA1083 data which I could use this unit Yakker to get into my IPad. The question is whether Opensource can interpret the data and give me radar targets. Thanks all

[Hakan]

Wayne..
OpenCPN is a program where the code is available for everyone, e.g. open source.


OpenCPN is not able to run on a IPad, sorry. You've to use Android tablets.
And there is no OpenCPN plugin supporting any Furuno radar.
So, the quick answer is; No.

Håkan

[Sailmonkey]

A furuno 1623 does not output radar data, and 0183 is too slow anyway to support the data required

[wstu]

Thanks Hakan

Sailmonkey the 1623 DOES output radar data per the manual at least that is how I am reading the manual. It says it outputs the TTL in NMEA0183 Ver 3.0, 4800 bps.

[Sailmonkey]

Originally Posted by wstu

Thanks Hakan

Sailmonkey the 1623 DOES output radar data per the manual at least that is how I am reading the manual. It says it outputs the TTL in NMEA0183 Ver 3.0, 4800 bps.

It will not support a radar display on another device

http://www.furunousaforum.com/viewtopic.php?f=5&t=1651

It will however output the target position to a plotter



4800 is just not fast enough to do the fancy stuff that a nema 2000 or Ethernet network will do.

[Hakan]

Originally Posted by wstu

Thanks Hakan

Sailmonkey the 1623 DOES output radar data per the manual at least that is how I am reading the manual. It says it outputs the TTL in NMEA0183 Ver 3.0, 4800 bps.

Well. that's another thing. Then it's not the radar picture that's transferred but what you can call an ARPA or MARPA target.

The TTL sentence is well understood by OpenCPN as long it's according to the NMEA 0183 specification. If so each target will show up as a round icon that behaves like an AIS target. See attached shot. In radar_pi plugin we can either detect ARPA targets by a guard zone or manually.

Try to connect the USB and add the corresponding serial port to OCPN's connections tab.

Håkan

[Paul L]

Hakan
How do you get an MMSI from an ARPA target- as displayed in your sample?

[Hakan]

Originally Posted by Paul L

Hakan
How do you get an MMSI from an ARPA target- as displayed in your sample?

First:
The ARPA NMEA 0183 sentence should be TLL and not TTL as I and wstu wrote above. A TTL sentence is not available in the NMEA 0183 standard so I hope wstu also meant TLL.
Second:
The MMSI number is produced by OpenCPN AIS_decoder.
The first measage field in TLL is a sequential number from 00 to 99 produced by the radar program, arpa_tgt_num. That number is used to produce the MMSI number in OCPN starting from 199200000
(mmsi = arpa_mmsi = 199200000 + arpa_tgt_num)
Håkan

[Paul L]

Originally Posted by Hakan

First:
The ARPA NMEA 0183 sentence should be TLL and not TTL as I and wstu wrote above. A TTL sentence is not available in the NMEA 0183 standard so I hope wstu also meant TLL.
Second:
The MMSI number is produced by OpenCPN AIS_decoder.
The first measage field in TLL is a sequential number from 00 to 99 produced by the radar program, arpa_tgt_num. That number is used to produce the MMSI number in OCPN starting from 199200000
(mmsi = arpa_mmsi = 199200000 + arpa_tgt_num)
Håkan

That's interesting. So this is an arbitary number that is internally assigned and then labeled and displayed as an MMSI.
Why display it as an MMSI at all?

[Hakan]

I suppose the easiest way to handle an ARPA target was to use the same logic as for the AIS targets and then we need an MMSI ID-number to handle things like CPA and others.
Håkan

[Paul L]

Originally Posted by Hakan

I suppose the easiest way to handle an ARPA target was to use the same logic as for the AIS targets and then we need an MMSI ID-number to handle things like CPA and others.
Håkan

Easy for the programmer, misleading for the user. Understandable.

[Hakan]

Paul..
Misleading..? How do you mean. What kind of misunderstanding or problem could be the result of this use of a MMSI ID at the actual number series?

Håkan

[Paul L]

Originally Posted by Hakan

Paul..
Misleading..? How do you mean. What kind of misunderstanding or problem could be the result of this use of a MMSI ID at the actual number series?

Håkan

Not a big deal. But displaying a number labelled as an MMSI that isn't is misleading. I could try and look it up on marine traffic or use it to determine the nationality of the target, etc. Now that you tell me it isn't an MMSI I know to ignore it, yet it is still labelled as one. I assume I'd have to dig into the manual to realize that as a user.

[Hakan]

Paul..
I see. Let's see if I can explain more.

They are following the MMSI rules. Here's the comment in the program:
mmsi = arpa_mmsi = 199200000 + arpa_tgt_num; // 199 is INMARSAT-A MID, should not occur ever in AIS stream + we make sure we are out of the hashes for GPSGate buddies by being above 1992*
That series don't have a MID for country codes like "normal ship" MMSI starting at 201000000 (to 774999999.)
rgds
Håkan

[Paul L]

Originally Posted by Hakan

Paul..
I see. Let's see if I can explain more.

They are following the MMSI rules. Here's the comment in the program:
mmsi = arpa_mmsi = 199200000 + arpa_tgt_num; // 199 is INMARSAT-A MID, should not occur ever in AIS stream + we make sure we are out of the hashes for GPSGate buddies by being above 1992*
That series don't have a MID for country codes like "normal ship" MMSI starting at 201000000 (to 774999999.)
rgds
Håkan

That explains that the number used is not a valid AIS MMSI, so it is somehow OK to use. I get how it came about. It still is displayed in a misleading way to a user. Of course, not misleading to a coder.