Tagged: AIS

AISRec Updated to Version 2.1

AISRec is an RTL-SDR (and now Airspy) compatible AIS (automatic identification system) dual channel decoder. AIS is an acronym for Automatic Identification System and is a system used by ships to broadcast position and vessel information. By monitoring AIS transmissions with the RTL-SDR we can build a boat radar system.

Last time we tried AISRec we found its performance to be very good, with it decoding more messages than other software we tried. The new version includes the following updates:

  • Added auto detection of devices when devices are plugged in.
  • Added the support for airspy. Allow selection of devices by serial number for rtlsdr dongles.
  • Added AISRec core 3.0. The new core is 2x faster than AISRec core 2.0.
  • Added one embedded multi-user TCP server. Any client works with AISRec should implement auto reconnection.
  • Added auto display of local IP for the TCP server.
  • Added one output to one serial port.
  • Added interactive changes of gain parameters for devices.
  • A few changes on GUI.
  • Added an icon for GUI. Users should reset the windows icon buffer to allow the display of the new icon.

In addition, while AISRec hopes to be commercial software one day, at the moment they are currently offering free registration. See their FAQ for information on registering for free.

AISRec running with OpenCPN.
AISRec running with OpenCPN.

Using AIS Share, OpenCPN and an RTL-SDR on a Sailboat

AIS Share is an app for Android that allows you to turn an Android device into an AIS receiver by using an RTL-SDR. AIS stands for Automatic Identification System and is used by ships to broadcast their GPS locations, to help avoid collisions and aid with rescues. An RTL-SDR with the right software can be used to receive and decode these signals, and plot ship positions on a map.

AIS Share is a dual channel decoder that outputs decoded NMEA messages via UDP, so that plotting software like OpenCPN can be used to display the ships on a map. AIS Share had been around before in another form known as rtl_ais_android which we posted before, but this version of AIS Share is a newly updated and improved version that now includes a very nice GUI. The app costs about $2 and is available on the Google Play store, but there is a demo available that will work up until 1000 messages are received. You will need an RTL-SDR and a USB OTG cable to run the app.

Recently the author of the app received word from a user called Harmen who has successfully been using his AIS Share app on his sailboat. Harmen uses the app on an Android tablet which is enclosed in a waterproof box. For an antenna he uses a coax collinear.

In the future the author writes that he’d like to update the app to support things like the ability to change more dongle settings like bandwidth/sample rate and add the possibility of using the internal phone/tablet GPS. He is also open to any community suggestions.

AIS Share Receiver on the sailboat in a waterproof case.
AIS Share Receiver on the sailboat in a waterproof case.
The back of the Android Tablet, showing the RTL-SDR and the antenna connection.
The back of the Android Tablet, showing the RTL-SDR and the antenna connection.
The AIS Share main screen GUI.
The AIS Share main screen GUI.

https://www.youtube.com/watch?v=ApGk8P82THs (Unfortunately the video has been removed)

AISRec: Windows and Android AIS Decoder

Back in 2015 we posted about the free trial version of AISRec a few times, but we never really saw a full completed version get released. So far this year the full version is still not released, but the programmer Jane Feverlay has created a website and uploaded the latest Windows version of their trial version software

AISRec is an RTL-SDR compatible AIS decoder that is made for Windows and Android. AIS is an acronym for Automatic Identification System and is a system used by ships to broadcast position and vessel information. By monitoring AIS transmissions with the RTL-SDR we can build a boat radar system. We have a tutorial on this here (using other software).

The last time we tried AISRec we found that it had very good ability at decoding AIS messages, especially very weak ones and was by far the easiest AIS decoder to set up and use on Windows. The features include:

1. Work with all rtlsdr dongles. Allow future support for other SDR devices.
2. Stable reception of AIS signals at as low as SNR 7 dB.
3. Tolerance to frequency drifts > 30 ppm.
4. Dual-channel reception at 161.975 MHz and 162.025 MHz.
5. Channel selectivity > 56 dB.
6. Low CPU usage. No problem for Atom CPU and above.
7. Output all types of AIS messages (including Class A and Class B) in NMEA formats to UDP ports.
8. Convertion of AIVDM to AIVDO messages for your own ship.
9. Display of the received NMEA messages and the statistics.

The author of AISRec writes in an email to us an explains that the trial version has a time limit and an RX message count limit for each run, whereas the registered lite version will not. The pro version will have some additional features. Currently the author has no method for taking in paid registrations, but plans to have this ready in the future. We will post again once registration is available.

AISRec Running with OpenCPN
AISRec Running with OpenCPN
AISRecWinFull (rtlsdr, AIS)
AIS box: AISRec for the raspberry pi 2. (rtlsdr, AIS)
AISRec for Android. (rtlsdr, AIS)

 

A new AIS Decoder for the RTL-SDR on Android

A reader of our blog, EBC81, has written in to let us know about a new RTL-SDR based AIS decoder that he has written for the Android OS. AIS stands for Automatic Identification System and is used by ships to broadcast their GPS locations, to help avoid collisions and aid with rescues. An RTL-SDR with the right software can be used to receive and decode these signals, and plot ship positions on a map.

EBC81’s program is called rtl_ais_android and can be downloaded from this GitHub link. It decodes the AIS data into NMEA messages, which can then be sent via UDP to mapping programs in Android or a program like OpenCPN on your PC. To use the app you will need a USB OTG cable to connect your Android device to the RTL-SDR.

In the future EBC81 hopes to create a second app which will display the ship positions on a map.

https://www.youtube.com/watch?v=sUkkcEq8FCU

New RTL-SDR software: rtl_ais

Over on cruisersforum.com we’ve seen news of a user who has worked to combine rtl_fm and aisdecoder into a single command line program called rtl_ais. AIS stands for Automatic Identification System, and is used in the marine industry to broadcast vessel GPS coordinates to one another to work as a collision avoidance radar system. With the correct software and an RTL-SDR, nearby boat AIS broadcasts can be received and the boat GPS coordinates plotted on a map.

Until recently, to decode AIS you had to pipe the AIS audio from software like rtl_fm or SDR# into a decoder. rtl_ais is a decoder which allows you to directly connect to the RTL-SDR and decode AIS without the need to pipe audio. The software is compatible on Linux and Windows and the current source code and Windows binary release is available at https://github.com/dgiardini/rtl-sdr-misc/releases/tag/v0.1.

The RTL_AIS help screen
The RTL_AIS help screen

AISRec for Android: New AIS Decoder

Back in December last year we posted about Jane feverlay’s work on his software called AISRec, which was a Windows AIS decoder for the RTL-SDR that he had developed.

AIS is an acronym for Automatic Identification System and is a system used by ships to broadcast position and vessel information. By monitoring AIS transmissions with the RTL-SDR we can build a boat radar system. We have a tutorial on this here.

Now from YouTube it looks as though Jane has developed a new Android version of AISRec which he describes as a high performance dual-channel AIS receiver for use with a single RTL-SDR dongle. The features of AISRec include:

1. Functions include AIS and GPS NMEA I/O, from/to USB devices and serial ports (special android devices with serial ports).
2. It supports TCP server and UDP forwarding jointly or independently for AIS and GPS.
3. It supports steaming in WIFI in AP or station modes and Ethernet.
4. It supports auto run on boot for especially rooted devices.

He also writes that AISRec also has companion implementations for Windows desktop and metro, Linux on Raspberry Pi 2 and the Radxa pro.

Unfortunately, at the moment there does not seem to be a link available to download the software and the video may only be a preview. The video does link to his Taobao shop at http://shop114459024.taobao.com/ (in Chinese use Google Translate), which is where he might release the software when it is ready.

AISRec for Android. (rtlsdr, AIS)

New Windows AIS Decoder For the RTL-SDR: AISRec

Over on YouTube user Jane feverlay has uploaded a video showing a new AIS decoder called AISRec for Windows that he has developed.

AIS is an acronym for Automatic Identification System and is a system used by ships to broadcast position and vessel information. By monitoring AIS transmissions with the RTL-SDR we can build a boat radar system. We have a tutorial on this here.

The new software is not free, but he offers a trial version that limits the run time to 20 minutes and 5000 max messages. The paid version removes these limits and also decodes both AIS channels simultaneously. The program monitors data from the RTL-SDR and sends decoded data out via UDP. Software such as OpenCPN can then be used to display the AIS data on a map.

We tested the trial version on our machine and found that it worked well at decoding AIS messages. To download the trial go to http://pan.baidu.com/s/1pJiEzEV and enter the code kn44. The download site is in Chinese, but it is obvious where to enter the code. We found the software to be virus free, but remember to always scan unknown software like this yourself. The full price of the software is unknown, but purchasing instructions are given in the trial download readme. The author also writes that his software now supports the Airspy, but not in the trial version.

Note that we discovered that the software doesn’t use a PPM correction setting as expected. Instead it uses a frequency shift setting. To set the shift in the AISRec.ini file, we had to calculate freqshift = 162.025 MHz – frequency of the second AIS channel as shown in SDR# with no PPM correction set.

Another similar software program that was released earlier is PNAis.

Airspy RTL SDR RTL-SDR RTL2832: AIS software receiver for airspy and RTL2832 USB dongles

New AIS Decoder for the RTL-SDR: PNAIS

Over on our Forums  has told us about his recently released an AIS decoder called PNAIS which appears to directly connect to the RTL-SDR and decode AIS data. After decoding it then outputs the decoded NMEA data via UDP, which could then be received and used in map plotting software such as OpenCPN.

AIS is and acronym for Automatic Identification System and is a system used by ships to broadcast position and vessel information.

PNAIS
PNAIS Decoder