AIS data

[FWB]

As many know, NASA Marine also produce an AIS engine which puts out data for use in chartplotting software as well as their new AIS RADAR device. This device is not waterproof nor sunlight readable so I had hoped that the Engine would work in chartplotters. I rang NASA Marine, they were very helpful but unable to tell me of any chartplotters that would support the NMEA data coming from the engine. They did send me the tech details of the NMEA output.
I sent this to Raymarine to find out which of their plotters would support the AIS data. Their reply...

Unfortunately, the current range of Raymarine products does not support AIS

So it looks as if the data can only be used on computers. I wonder if I'm alone in wishing to have this data in the cockpit?
I appreciate that there are previous threads on the relevance of AIS, but I'm just sharing the info I have received.

 

[jonjo]

NMEA to Bluetooth converters already exist.

It should be within the capabilities of a collaborative hobby software project to read the NMEA data on a pocket PC and present AIS CPA vectors.

 

[Piers]

Like you, I would like to show AIS data on my chartplotter. So, when Raymarine or Simrad introduce a suitable chartplotter which can support an AIS input, I will be upgrading. Until then, no.

 

[david_bagshaw]

Seaclear works along with a program from shipplotter.com, but still need laptop.

 

[mogensl]

In the 2005 catalogue from german supplier svb at www.svb.de two makes of plotters supporting AIS input are mentioned; VDO and Standard Horizon.

Which NASA unit is it that will supply AIS data via NMEA?

Best of luck, and thanks
Mogens Lindstrøm

 

[FWB]

The NASA Marine product is simply called an AIS Engine. No doubt they can give you a list of suppliers. I will look at the vdo and standard horizon. Thanks.

 

[Amphitrite]

I am currently developing a software to display the data from the AIS engine on a laptop as a kind of "radar display" because I could not find any software (except SeaClear) which is capable of handling AIS data. I know, AIS has nothing to do with radar (don't bash me), but a screen with rings in different ranges is also useful for AIS data and CPA/TCPA calculating.
Holger

 

[Oldhand]

Software for plotting AIS data is already available. ShipPlotter will either plot directly form a suitable receiver output, doing the decoding in the software, or will plot incoming NMEA AIS data. It can also output NMEA AIS data. It works fine using the Packet output of an ICOM PCR1000 receiver tuned to one of the two AIS VHF FM frequencies, so if you have a suitable receiver and a PC, you don't need a dedicated AIS receiver or "engine".

 

[jonjo]

Re: Do you need a Beta tester?

Just say the word and I will order the Nasa engine.

 

[Amphitrite]

Re: Do you need a Beta tester?

Software is still under development, but you can take a look at www.yacht-ais.de . I'll give you notice if it is ready for testing...

Cheers,
Holger

 

[Oldhand]

Re: Do you need a Beta tester?

Why not use ShipPlotter which already exists?

 

[Ships_Cat]

I think you will find that most electronic charting systems support display of AIS data. I have not done any search but the one I use does (Endeavour Navigator) as do many others that I have come across casually eg MaxSea, Euronav. Oldhand has mentioned another.

John

 

[Oldhand]

You are right of course but with MaxSea for example, you have to buy the expensive "radar" package before you can dispaly AIS data. All the applications you mention require AIS data to be input on NMEA, the difference with ShipPlotter is it can decode raw AIS radio signals directly from a suitable non dedicated communications receiver. I'm watching traffic in my local coastal area right now using an ICOM PCR1000 receiver and ShipPlotter and if it works OK with my boat PC and receiver installation, I will have no need for any other equipment for AIS ship plotting.

 

[jonjo]

[ QUOTE ]
if it works OK with my boat PC and receiver installation, I will have no need for any other equipment for AIS ship plotting.

[/ QUOTE ]
What % load on the PC's CPU do you seen while the PC is digesting the raw VHF/AIS signal from the ICOM?

 

[Oldhand]

13% on a XP2800+. Still do everything else while its running in the background, just like now. /forums/images/graemlins/smirk.gif

 

[tome]

How many targets are you tracking? I would expect the processor load to increase with more target data to decode as any unused slots can be ignored.

 

[Oldhand]

5 is the most I have tracked at once 'cause a) I'm 4 miles inland and b) I'm not using a VHF antenna. Each AIS transmission is only 35ms, it would take an awful lot of them to bog down the processor and there is nothing to prevent the operating system missing some transmissions if there are higher priority tasks to do. You don't need to have ship's data every 10 seconds to be able to know what its doing unless its turning round to berth or something similar.

 

[Oldhand]

Second reply after further study:

ShipPlotter appears to use a "free running" decoder so it is trying to decode continuously whether there is a signal or just noise. As a result it doesn't matter how many AIS signals there are the docoder will always use the same amount of processor resources. The only thing that will increase with many signals is the logging (all decoded data can be viewed as text) and the plotting, which are not very heavy tasks. /forums/images/graemlins/laugh.gif

 

[Ships_Cat]

I took Amphitrite's post's reference to "AIS engine" in the usal use of that word in that it outputs NMEA sentences. Looking at the site he refers to (his own perhaps?) it is not clear whether the software it promotes takes raw audio ex a radio receiver or NMEA ex an AIS engine.

Perhaps Amphitrite could clarify what it does?

In the end, as I think we are both saying, modern ECS's already plot AIS data and ShipPlotter exists already to display raw audio ex a receiver.

John

 

[Oldhand]

Yup!