Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 30-07-2015, 05:45   #316
Registered User

Join Date: Aug 2014
Location: Argentina
Boat: H20
Posts: 55
Re: New rtlsdr Plugin

Quote:
there are large high speed ferries doing 40 kts
Ferries....
Is interesting to share experiences that show differents situations. The "Instructions in Notices to Mariners" are scary, no doubt in such scenario your criteria is very reasonable
__________________

__________________
piluso is offline   Reply With Quote
Old 30-07-2015, 06:20   #317
Registered User

Join Date: Aug 2011
Location: Mississippi Gulf Coast
Boat: 37' TransPac Trawler, heavily modified
Posts: 88
Re: New rtlsdr Plugin

Quote:
Originally Posted by the_muck View Post
That is interesting... on this weekend i can test a bit more . can you tell something about the stick and start oparators?
The sdr stick that I use is a NooElec R820T2 Amazon.com: NooElec NESDR Mini 2 USB RTL-SDR & ADS-B Receiver Set, RTL2832U & R820T2 Tuner, MCX Input. Low-Cost Software Defined Radio Compatible with Many SDR Software Packages. R820T2 Tuner & ESD-Safe Antenna Input, Guaranteed: Electronics

"C:\SDCard\Program Files\rtl_ais_win_v0.1\rtl_ais.exe" -p74 -g 38 -n are the parameters for rtl_ais program.
__________________

__________________
LeoA is offline   Reply With Quote
Old 30-07-2015, 07:35   #318
Registered User
 
boat_alexandra's Avatar

Join Date: Aug 2009
Location: BVI
Boat: bristol 27
Posts: 2,675
Re: New rtlsdr Plugin

Quote:
Originally Posted by piluso View Post
I think a library could be built using MinGW and used into VC. I'll try this as a next step.
This is like to automate a graphical method, seems to be feasible, would be great if we can code it.
I think I'll try to build it in for linux, then maybe you can make it work on windows?

It would be cool to autocalibrate from AIS in an intelligent way, but also we can code an option to transmit on a known vhf frequency which a lot of people can easily do to quickly calibrate the dongle.

Any more news on softfm vs rtl_fm? I would like to offer different filters. The more feedback I am seeing it is less and less clear what setup is optimal... Probably has more to do with the antenna than anything else.
__________________
boat_alexandra is offline   Reply With Quote
Old 30-07-2015, 10:03   #319
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 8,082
Re: New rtlsdr Plugin

Sean,
QUOTE]Can code an option to transmit on a known vhf frequency which a lot of people can easily do to quickly calibrate the dongle.[/QUOTE] Good thought, Yes.

At first I understood this incorrectly which leads to the next question. Is there some way to manually transmit using VHF DSC Vessel name, mmsi, lat long, course, speed? Kind of a manual AIS transponder? --Maybe this is way to convoluted. You are just going to get on the VHF and hail the boat.

I wish I'd gotten the newer noelec dongle, but I tried them again.

This time I followed:
RTL-SDR Tutorial: Cheap AIS Ship Tracking - rtl-sdr.com
Quote:
To set up an AIS ship radar on a windows system you will need four things.
  1. An RTL-SDR dongle working with SDRSharp.
  2. An audio piping method.
  3. A vertically polarized antenna tuned to 162MHz.
  4. Software for decoding the AIS signals.
In particular Item #2 using Windows Stereo Mix
Tutorial: How to Enable Stereo Mix in Windows 7 - rtl-sdr.com

I thought that was the missing link to Opencpn, but stilll no dice. the Rtlsdr dongle sort of works in SDRsharp etc and not in Opencpn.
__________________
rgleason is offline   Reply With Quote
Old 30-07-2015, 10:44   #320
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 8,082
Re: New rtlsdr Plugin

Boston tests:
1. Rooftop with DVB-T+DAB+FM USB dongle and rough AIS Colinear Antenna. Nothing
2. Out Window 50' high AIS antenna horizonatal with dAISy AIS reciever. 20 ships
3. Out window with DVB-T+DAB_FM USB and AIS antenna. Nothing.
--Rooftop is not really a viable location, too many buildings in direction of harbor with no signal.

Some pics showing the rough antenna and coil with duct tape on the roof, then later antenna out the window horizontal with dAISy receiver.
Attached Thumbnails
Click image for larger version

Name:	Antenna-on-roof.jpg
Views:	146
Size:	292.3 KB
ID:	106359   Click image for larger version

Name:	Antenna-Coil.png
Views:	137
Size:	218.5 KB
ID:	106360  

Click image for larger version

Name:	GPS-BU-353S4+DVB-dongle+Hub.jpg
Views:	145
Size:	195.0 KB
ID:	106361   Click image for larger version

Name:	20ships-antenna-horizontal-50ft-high.jpg
Views:	147
Size:	141.1 KB
ID:	106362  

Click image for larger version

Name:	dAISy+Holux240Slim-BT-GPS-setup.jpg
Views:	248
Size:	102.5 KB
ID:	106363  
__________________
rgleason is offline   Reply With Quote
Old 30-07-2015, 10:49   #321
Registered User

Join Date: Aug 2014
Location: Argentina
Boat: H20
Posts: 55
Re: New rtlsdr Plugin

Quote:
I think I'll try to build it in for linux, then maybe you can make it work on windows?
Sure, I can try !
Beside all the parameters actually used, would be nice to be able to change some of them at runtime: ppm_error,gain, turn on/off rtl AGC, turn on/off debug messages (audio level, nmea senteces), for a fine tunning directly from the plugin (may be in advanced mode).
Quote:
It would be cool to autocalibrate from AIS in an intelligent way, but also we can code an option to transmit on a known vhf frequency which a lot of people can easily do to quickly calibrate the dongle.
It's a good option, I think the only drawback is that an onboard, or neighbor VHF as RF source will deliver a signal too strong for this may be.
__________________
piluso is offline   Reply With Quote
Old 30-07-2015, 17:11   #322
Registered User

Join Date: Jul 2015
Posts: 12
Re: New rtlsdr Plugin

Tried rtl_ais successfully this afternoon, and found it uses only 25% or less CPU than AISRec. It's very simple to use with a .bat file. Tracked High Speed Ferries leaving port, but lost signal @ 9 nm range (speed then 35kts), which was about half the antenna horizon. I could still see it. Max range for any target was just over 10 nm but for slower surface targets. I suspected a doppler problem until I got a signal from a SAR heli @ 11 nm doing 139 kts. I'm using a "100KHz-1.7GHz full band UV HF RTL-SDR USB Tuner Receiver/ R820T+8232 Ham Radio" which is more stable than the original dongles with a correction of only -5ppm, and also far more versatile.
__________________
Maelruan is offline   Reply With Quote
Old 31-07-2015, 03:18   #323
Registered User

Join Date: Apr 2013
Posts: 2
Re: New rtlsdr Plugin

As an update, I have everything now running under Windows 10 without any issues so far. I did have to delete the dongle from the control panel, install and re-run Zadig 2.1.2 to enable it. SDRConsole, rtl_ais and OpenCPN seems to be running fine.
__________________
bluegoose57 is offline   Reply With Quote
Old 31-07-2015, 07:22   #324
Registered User

Join Date: Aug 2014
Location: Argentina
Boat: H20
Posts: 55
Re: New rtlsdr Plugin

Thanks your feedback Maelruan.

Could you please start rtl_ais using -s12k (default is 24k) , and tell us if you see any improvement ?

Regards,David
__________________
piluso is offline   Reply With Quote
Old 31-07-2015, 13:11   #325
Registered User

Join Date: Jul 2015
Posts: 12
Re: New rtlsdr Plugin

Hi Piluso,
I'm ashore now, and tried -s12k and other values with a spare Slim Jim out the window. -s17K seemed to work a little better than 12. Also varied other arguments. Better overall results using SDRSharp & Shiplotter with the same hardware. 6nm was greatest range from home. It will be a day or 2 before I can try it on board.
__________________
Maelruan is offline   Reply With Quote
Old 01-08-2015, 19:16   #326
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 8,082
Re: New rtlsdr Plugin

Regarding 162 mhz colinear antenna location. Can I secure it to the backstay? Must it be vertical? Must it be away from and not aligned with other metal things like stays backstay radar mount pipes, etc?
Could I find a hollow fiberglass rod mount it in that and attach that vertically next to the backstay pole mount radar 9' high?
__________________
rgleason is offline   Reply With Quote
Old 01-08-2015, 19:22   #327
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 8,082
Re: New rtlsdr Plugin

PS the very simple duct tapped antenna taped to our stern pulpit pops up more "contacts" than I can believe. Everyone seems to have AIS transponders, boats I would not expect..
__________________
rgleason is offline   Reply With Quote
Old 01-08-2015, 19:29   #328
Registered User
 
rgleason's Avatar

Join Date: Mar 2012
Location: Boston, MA
Boat: 1981 Bristol 32 Sloop
Posts: 8,082
Re: New rtlsdr Plugin

There are lots of cpa alarms and there seems to be a scale difference between when I normally get attentive and the greater distance of the alerts. This could become a bother acknowledging all the alerts. I will have to study the setting in greater detail.
__________________
rgleason is offline   Reply With Quote
Old 02-08-2015, 08:17   #329
Registered User

Join Date: Aug 2014
Location: Argentina
Boat: H20
Posts: 55
Re: New rtlsdr Plugin

Quote:
there seems to be a scale difference
"Objects in AIS are closer than they appear."
Happy sailing !
__________________
piluso is offline   Reply With Quote
Old 03-08-2015, 10:23   #330
Registered User

Join Date: Jul 2015
Posts: 12
Re: New rtlsdr Plugin

My best results with RTL_ais using Slim Jim 162Mhz antenna, -g43, & -s25k, are ranges for AtoN 18.6nm, & 14nm for a 29m high ship.
Results with AISRec are still better, also using g43: AtoN 47.4nm (this is on an elevated site), ship 22nm, albeit with far higher CPU demand.
Ranges using a 162Mhz colinier were about half in each case.
Encasing antennas in a non conductive tube & keeping them clear of other conducting material should preserve their designed characteristics. I've been using a Slim Jim encased in a PVC tube very successfully as a temp (2 yrs now) replacement for the u/s VHF whip at the top of my mast.
__________________

__________________
Maelruan is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Logbook Konni for OpenCPN konni OpenCPN 822 14-02-2017 19:01
OpenCPN Release Candidate Version 3.1.1411 Released bdbcat OpenCPN 48 24-02-2013 06:59
GRIB Weather Mark Ward OpenCPN 26 12-02-2012 21:33
Route Properties, Missing Functions James Baines OpenCPN 13 13-07-2011 04:31


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 01:50.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.