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-   -   Keeping track of our lifeguard rescue boats? (http://www.cruisersforum.com/forums/f134/keeping-track-of-our-lifeguard-rescue-boats-184144.html)

Rince 02-05-2017 10:26

Keeping track of our lifeguard rescue boats?
 
Hi,

we´re wondering how we could keep track of our rescue boats, and if OpenCPN could be of any help :)
We´ve got 14 rescue boats located on 10 different lifeguard stations (with internet).
The equipment is from nothing but a fast going engine, up to 3D deep scanners.

We cover about 25 sq mi. :thumb:

Our basic idea:
For sake of simplicity, we would like something like this on every boat:

Raspberry
GPS
battery pack
3G or LTE for uplink
(kind of black box; once installed, forget it)


Our basic idea is creating VPN connections including the stations and the boats.

The 10 stations should be able to run their own OpenCPN instance and receive the GPS data from every boat.

As far as I´ve been reading, OpenCPN is not able to handle different GPS data.

But using something like AIS could do the trick?

So, we would need a small program on each boat-RasPi receiving GPS data, converting it to something like AIS and making it available in our network.

So OpenCPN could receive these "AIS" signals and display the boat's location on the chart.


Now:
1. Is this possible?
2. Is there any software around generating AIS over network? (also if 10 instances of OpenCPN are trying to connect)?

3. Do you know any better (or working) solution? (perhaps something like a MQTT broker?)


Thank you very much in advance :thumb:

Rince

PS:
Using any public servers is a no go...

bcn 02-05-2017 10:48

Re: Keeping track of our lifeguard rescue boats?
 
You might look at OpenPlotter (= Navigation and sensor package with OpenCPN on RasPi, including multiplexing) and their SignalK implementation.

In SK the originator or source is one part of the data set, multiple sources for the same type of data are part of the spec.

Tunnel the data to your base.

At your base you would need to map the different SK streams to either faked AIS NMEA signals or perhaps easier to GPS Buddy (--> at the OCPN manual).

There have been discussions about towing a barge with its GPS and how to get the signal as an own object into OCPN not that long ago. Search at the forum.

Several pieces of software to generate NMEA0183 data sets are available as well.

Hubert

Hakan 02-05-2017 13:59

Re: Keeping track of our lifeguard rescue boats?
 
Rince..
If you could generate IP messages from each rescue boat via an Internet server it would be possible to get them visible on a OCPN screen.
If each GPS position where converted to a NMEA0183 message $xxTTM and sent to a IP network connected to OCPN the targets will show up as an ARPA target. An ARPA target is acting like an AIS target and position, course and speed will be shown. Each boat can send there's name for identification.

Hubert is referring to the discussion here: http://www.cruisersforum.com/forums/...ml#post2301647

Håkan

Jim Cate 02-05-2017 14:23

Re: Keeping track of our lifeguard rescue boats?
 
I may be a bit dense, but why would you not simply put an AIS transceiver on each boat and track them via normal AIS protocols?

Jim

Rince 02-05-2017 23:16

Re: Keeping track of our lifeguard rescue boats?
 
Thank you all for your ideas.
I appreciate them very much.

@Jim
This is a matter of costs I think, but feel free to correct me:

RasPi 40$
Battery pack with 12 V ~ 40$
GPS ~ 50$
LTE ~ 30$
Waterproof case: 10 $ and a little diy
Subscription (uplink): free to 5 $ / month


At the stations:
Existing computers
Or, RasPi kit ~ 80 $



@bcn & hakan
Will reply soon, have to do some reading first :)

OpenCPN is one of two ideas in my mind:
Other idea is adopting my home automation system. Basically, I would have to write a few lines of code converting GPS to pixels on the chart.

So, it would look like this:
Boat+RasPi+GPS+LTE => VPN => MQTT broker in one main-station => home automation in every station OR home automation in one station and others do simply connect via browser

+ I know the system
+ Minimal bandwith on LTE (only one time GPS to MQTT for unlimited stations receiving)
+ small footprint on RasPi
+ expandable
+ eye candy (like blinking lights for storm warnings)

- resolution dependend (home automation can't use real charts)
- no navigation possible (but that wasn't on the todo list anyway)


So, it looks like SK would act as kind of MQTT broker. Question is, if it is possible to run SK only in one station for sake of bandwith.

GordMay 03-05-2017 02:40

Re: Keeping track of our lifeguard rescue boats?
 
Greetings and welcome aboard the CF, Rince.

TravellingKiwis 03-05-2017 02:57

Re: Keeping track of our lifeguard rescue boats?
 
I really like your ideas and with the challenge you are trying to resolve I can see how money would be an issue. I have absolutely no doubt you would be able to build a cheaper system as you have planned but I do see a few possible challenges:
- You will need everything on the boats to be able to handle the lifeguard rescue marine environment which I imagine is not all 'plain-sailing'.
- It would have taken a bit of technical fiddling so fails the KISS principle and could have issues when you least expect it. In life and death rescue situations, can you really afford for this to happen.
- It may have a higher ongoing operational cost eg 10 x Data SIMs either prepaid with ongoing topups or on contract.
- It will be limited by mobile coverage.

I agree with Jim Cate, this sounds exactly what AIS was designed for so I would suggest a pure VHF AIS solution:
- VHF generally has better coverage than mobile but clearly subject to location of your 'home base'and the terrain / coverage of the 25sq mi you cover.
- Will not only allow the base to see all boats and all of the boats to see each other but also other vessels with AIS can see / be seen!
- Will plug into any NMEA network any of the boats already have and allow easy future NMEA expansion.
- Keeps the solution simple and robust with lower ongoing costs BUT will have a higher set up cost


I would suggest the Vesper Marine XB-6000:
Waterproof - designed for marine environment
Wifi / USB - allows for wireless or wired connection for data to be pushed to a desktop, smartphone or tablet which you can put an app (OpenCPN or other) on to display the data. You can connect up to 5 wireless devices without needing a seperate router.
NMEA 0183 and 2000 - allows data from other NMEA sensors to be shared as well and will also allow AIS data to be shown on NMEA attached MFDs (assuming your bigger boats have these?)
GPS Receiver - with internal antenna but usually comes with external as well.
VHF Receiver - can have own external VHF antenna or add splitter to use existing VHF radio antenna.


Now clearly at around £540 a piece without power supply connection, splitter etc this is likely to be outside your budget but a couple of thoughts on this:
- you should consider how long you planned solution is going to last for (3-5 years?) and calculate the SIM Data costs over this lifetime.
- perhaps you could approach Vesper Marine directly to see if you can get at cost or wholesale in return for a written and video case study about the setup for 10 boats and benefits it brings. A life guard case study must be pretty valuable.
- If still not affordable for all boats but you end up with an AIS solution, perhaps you could just install on any bigger boats you have that already have NMEA backbones, an MFDs and VHF antenna.

All the best. I am sure that what-ever solution you end up with will bring a huge benefit over what you have now!

AedanC 03-05-2017 05:25

Re: Keeping track of our lifeguard rescue boats?
 
If considering AIS you might want to ask is the update interval sufficient for your requirements.

For the Pi based solution you need to add a 12v to 5v converter into your bill of materials. They are quite cheap.

Moo 03-05-2017 18:04

Re: Keeping track of our lifeguard rescue boats?
 
Quote:

Originally Posted by AedanC (Post 2384667)
If considering AIS you might want to ask is the update interval sufficient for your requirements.

Yes.. several minute updates are probably not sufficient in an inshore SAR situation - definitely needs thought before "diving in".

rgleason 10-05-2017 13:02

Re: Keeping track of our lifeguard rescue boats?
 
Why not include an AIS transponder on each boat?
This would then use the AIS system as intended and you would not need the 3G or LTE uplink and there would be no special programming involved!

Jim Cate 10-05-2017 13:48

Re: Keeping track of our lifeguard rescue boats?
 
Quote:

Originally Posted by rgleason (Post 2390288)
Why not include an AIS transponder on each boat?
This would then use the AIS system as intended and you would not need the 3G or LTE uplink and there would be no special programming involved!

See post #4 above. Still seems the best way t go, and prices keep coming down on AIS systems.

Jim

Moo 10-05-2017 15:23

Re: Keeping track of our lifeguard rescue boats?
 
Quote:

Originally Posted by Jim Cate (Post 2390312)
See post #4 above. Still seems the best way t go, and prices keep coming down on AIS systems.

Jim

Yes the price comes down but the technology doesn't change. The update rate is probably too slow to accurately report high speed rescue craft and their rapid changes of course and speed, while engaged in an inshore rescue operation.

They would be better off looking out of the lifeguard tower with binoculars than looking at an AIS plot several minutes old.

Jim Cate 10-05-2017 16:27

Re: Keeping track of our lifeguard rescue boats?
 
Quote:

Originally Posted by Moo (Post 2390394)
Yes the price comes down but the technology doesn't change. The update rate is probably too slow to accurately report high speed rescue craft and their rapid changes of course and speed, while engaged in an inshore rescue operation.

They would be better off looking out of the lifeguard tower with binoculars than looking at an AIS plot several minutes old.

Valid poiint about update rate, but I'm a bit unsure of t he need for folks on shore needing instantaneous knowledge of where the SAR boats are, especially if maneuvering at high speed. Perhaps I don't understand the mission well enough to comment, so I'll back out of the discussion.

Jim

rgleason 17-05-2017 13:21

Re: Keeping track of our lifeguard rescue boats?
 
I think that perhaps this application requires a more instantainous of the shelf solution combined with OpenCPN and the Navico Broadband Radar using Marpa. Sorry I had not thought of this earlier. Each boat would need a radar at about $1500, but perhaps the Ais could be dropped, but the id of the fleet would be lost.

Another alternative which would be even cheaper, but might be more work and be more complex for the crew, is to use DSC/ VHF fleet calling with position information included. This type of call can be initiated when needed and fits in the stanard vhf protocal, which perhaps the mother landbase can use to update and publish a complete fleet database to the vessels (added programming).
This might prove to be the cheapest solution if it can be programmed.

Please keep us appraised on your decisions and progress as we are interested and someone may be able to help.

Rasbats 17-05-2017 14:40

Re: Keeping track of our lifeguard rescue boats?
 
AIS Class B SOTDMA is becoming available.

Mike


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