How to Install OpenCPN on Your AIS Raspberry Pi for Maritime Research

6 min readAug 27, 2021

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This method works as of 8/25/21

OpenCPN is chart plotter navigation software designed for charting a course and tracking your position on a boat straight from your own device. For my purposes, I installed OpenCPN to track vessels and learn how to research and manipulate AIS. I work a lot in the Maritime OSINT space and regularly see vessels obscuring/changing things such as their identities, locations, and draught and I wanted a deeper knowledge of how that is possible.

In my previous blog, Creating an AIS Pi for Maritime Research, I walked through how to build a Pi with a dAISy Hat and antenna to pick up AIS signals. This is a continuation of that process that will show you how to install the OpenCPN program and begin using your Pi to capture AIS.

The application found on opencpn.org works on Windows, Mac, Linux, and Raspberry Pi (I am using a Raspberry Pi 4 with Rasbian) and involves three steps: Installing OpenCPN, downloading charts, and setting up GPS or NMEASimulator to track AIS.

Admittedly, I am terrible at using the command line and therefore found the documented installation to be somewhat difficult. You can find the official install instructions here but some of the commands have since been depreciated (apt-key command) causing the installation to fail. I intend to walk through the installation step-by-step including those missing steps.

A Note Here: Another option would be to use Open Plotter which is a complete OS for Pi with OpenCPN already installed.

First, let’s create a PGP key file:

Navigate to the PGP keyserver
Enter the key:0xC865EB40
All options should be turned off except “Get Verbose index of matching keys”
Click “search for a key”
Click on the link that is shown beside “pub”
A new page opens with the PGP key

Image is screenshot of PGP keyserver — Go to the PGP Keyserver

image shows to click the link beside the word pub — click on the link beside pub

Image shows generated PGP Key Block — Get PGP Key block and copy/paste into file

On the Pi, if you haven’t created an OpenCPN directory let’s do that now:

mkdir ~/opencpn
cd ~/opencpn

In your opencpn directory create a text file named opencpn_key
Copy the PGP key from “ — -BEGIN PGP PUBLIC KEY BLOCK — -” to the end and paste it into your new text file. Save and close.

nano opencpn_key.txt

Run the following command to verify that the file is actually a PGP key.

file opencpn_key.txt

Next, download and install OpenCPN:

Once Raspbian is running on your Pi, go to Menu →Accessories →Terminal, and type:

sudo nano /etc/apt/sources.list

A text editor will open, move the cursor to the end of the file and add the following code (if you are using the latest Buster)

deb [signed-by=~/opencpn/opencpn_key] http://ppa.launchpad.net/opencpn/opencpn/ubuntu/ bionic main

Save the file by pressing Ctrl X, say Yes, and press Enter.
Go back to the Terminal and type:

Sudo apt install dirmngr

Make sure you are connected to the internet and type the following to update the Software sources:

sudo apt-get update

Finally, type the following to install OpenCPN:

sudo apt-get install opencpn

Configure and Run OpenCPN:

OpenCPN can be Run by typing opencpn in the Terminal or by clicking on the Application icon under Education.

Image shows how to open OpenCPN by clicking on Education then OpenCPN — Open application in the OS

In OpenCPN, downloading and installing charts is how we get AIS and map views for a specific region. To install charts we can use the Chart Downloader tab.

Shows image with Chart Downloader Tab open — Click on chart Downloader Tab

Click on the Chart Downloader tab
Click the Add button to see all the charts in the catalog and select one that interests you.
Following the original guide, I chose USA NOAA & Inland Charts

Image shows panel where you can select chart groups — Select the charts you want to look at

Click OK to see more chart format options. In the case of the NOAA charts, they can be viewed by state, region, district, etc. I selected “by Region.”

Image shows panel that allows you to select a specific regional chart — Select the Region you would like to view

Scroll down to select the Region you want to add, I selected Florida East Coast and the Keys

Image shows panel of specific Regional charts you can download — Select the region you want to download

Download the catalog into your directory by clicking Update.

Image shows panel where you can click update to download the charts to your directory — Click update to download the catalog

This will populate chart names in the box below where you can turn off any you don’t need.

Image shows panel allowing you to turn off and on the charts you don’t want to download — Turn on/off the charts you don’t want to download

Click the “Download Selected Chart” button

Image shows the charts in map view on OpenCPN — Final downloaded charts in OpenCPN

Configure your Data Source

Click on Options
Click Connections
Scroll down and click Add Connection button

Image shows panel with connections tab selected — Select Connections tab

If you are using the dAISy Hat:

Under properties click the Serial radio button
Enter ‘/dev/ttyS0/ or ‘/dev/serial0’ in the DataPort field
Select Baudrate of 38400 and click OK

Image shows Serial button selected and settings input — Select Serial radio button and input settings

If you are using another device and getting your feed through the network:

Click the Network radio button
Select the protocol
Enter your device IP
Enter the protocol port number
Click OK

Panel shows the networking tab which enables you to configure an external device feed — Get a feed from an external device by configuring the Network tab

To test your connection, click Show NMEA Debug Window to see the sentences transmit.

Using NMEA Simulator to generate sentences for AIS research

Because I am located over 10+ miles from a body of water, I will need to test OpenCPN with sample AIS data. We can simulate vessel movement and information such as speed and position based on data we provide by using the NMEASimulator.

To send the data to OpenCPN we need to enter the IP and listening port in Settings under the Server section.

Set your listening port/IP here which will be different than shown here

Set up the simulated data in the Simulator Starting Values section

Start OpenCPN and click the Play button in NMEA Simulator to view the simulated AIS data within OpenCPN!

I hope that you enjoyed this walkthrough and are able to create your very own AIS Pi with OpenCPN data. I had a lot of fun working through this project. A huge thanks to Gary Kessler for inspiring my original AIS Pi project and providing much of the data for this one. Be sure to check out his site for more info and projects in maritime cybersecurity.

Finally, a special thanks to @theprescomm for helping me figure out the errors in my Linux commands which were plentiful.