161MHz AIS decoder

The installation of an AIS decoder to detect ships around Melbourne.


Examples

Here are some example screenshots of OpenCPN with AISRec on Windows.

A Passsenger Ship

A Passsenger Ship

A Tanker

A Tanker

A Cargo Ship

A Cargo Ship

A Search and Rescue Vessel

A Search and Rescue Vessel

A Sailing Vessel

A Sailing Vessel

An interesting vessel is the SAR (Search And Rescue) Aircraft. It appears on both the AIS network and the ADS-B network.

A SAR Aircraft A SAR Aircraft

A SAR Aircraft

A Base Station

A Base Station

A Virtual Reference Point

A Virtual Reference Point

A Virtual Reference Point

A Virtual Reference Point

A vessel in Western Port Bay

A vessel in Western Port Bay

A Pleasure Craft

A Pleasure Craft

A tug

A Tug

A Victoria Police Vessel

A Victoria Police Vessel

An Australian Navy Vessel

An Australian Navy Vessel

A Beacon

A Beacon

A Fixed Structure

During Tropospheric Ducting, A Fixed Structure

A Tasmanian Base Station

During Tropospheric Ducting, A Tasmanian Base Station


Software Defined Radio Waterfall

Here is a video of the SDR# waterfall for AIS reception at 161.975 MHz and 162.025 MHz.

AIS Signal Waterfall


Hardware

The receiver uses an RTLSDR usb dongle and an indoor antenna.

During 2019 I updated the antenna from a magnetic base antenna to a rabbit ears antenna.

AIS Magnetic Base Antenna

AIS Magnetic Base Antenna

The magnetic base antenna specifications say 136-174 MHz and 400-480 MHz which includes AIS at 161 MHz. There was not a more specific magnetic base antenna on ebay. It cost $12.

AIS Rabbit Ears Antenna

AIS Rabbit Ears Antenna

The rabbit ears antenna is for generic VHF reception. Installed with the elements aligned vertically. Sold from Radio Parts at a sale cost of $6.

The RTLSDR usb dongle cost $14 on ebay.

The 3m usb cable cost $9 on ebay.


Software

There is a webpage on making an AIS decoder using an RTLSDR dongle on rtl-sdr.com
https://www.rtl-sdr.com/aisrec-updated-to-version-2-1/

This reception solution uses the AISRec and OpenCPN.

The home page for AISRec is:
https://sites.google.com/site/feverlaysoft/home

The Windows version is used i.e. AISRecWin.

Here are the network settings used.

AISRec Settings for Windows

AISRec Settings for Windows

The home page for OpenCPN is:
https://opencpn.org/

Here are the network settings used to connect OpenCPN to AISRec.

OpenCPN Settings for AISRec for Windows

OpenCPN Settings for AISRec for Windows

The Windows version of OpenCPN with an added map of Port Phillip Bay is configured using GE2KAP and Google Earth.

A blog detailing OpenCPN and GE2KAP, developed by Paul Higgins, is found at:
https://opencpn.wordpress.com/2016/04/10/make-charts-on-google-earth-with-ge2kap/

Here is a screenshot of OpenCPN before and after installing a Google Earth view of Port Phillip Bay.

OpenCPN Before GE2KAP

OpenCPN Before GE2KAP

OpenCPN After GE2KAP

OpenCPN After GE2KAP

This is what the running report from AISRec looks like after successful reception of AIS transmissions.

Example of AISRec running on Windows

Example of AISRec running on Windows