AIS-catcher is free, open-source software that uses compatible radio hardware or other supported inputs to receive and decode ship AIS broadcasts. It can show decoded NMEA messages locally or send them to other applications and services. It is a receiver, not a transmitter or a complete radio station: you supply compatible hardware and an antenna.
What is AIS-catcher?
Automatic Identification System (AIS) broadcasts carry vessel identity and movement information, including position, speed and course. AIS-catcher listens for those broadcasts over VHF and decodes them into NMEA messages. It supports two AIS channels and can be operated from a command line or through a browser control panel.
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The project describes AIS-catcher as free and open-source software. Its current supported inputs include several software-defined radio (SDR) families as well as network and file sources; the exact hardware and dependencies available to you depend on your operating system and installation method. See the AIS-catcher project repository and official documentation for current details.
What equipment do you need?
A typical station consists of a computer, an AIS-catcher-compatible receiver and a VHF antenna. The Quick Start names a Raspberry Pi, PC or Mac as computer examples, and an RTL-SDR dongle or dAISy-catcher receiver as hardware options. It recommends an antenna tuned to approximately 162 MHz.
#1 Best Overall
- Turn your computer, phone or tablet into a radio scanner/ham radio receiver that can receive nearly all RF signals! Compatible with Windows, Mac OS, Linux, and Android
- NESDR SMArt RTL-SDR v5 can be used for the reception of broadcast AM radio, broadcast FM radio, shortwave radio, CB radio, public security radio, trunked radio, air traffic control, ACARS (plane-ground communications), ADS-B (plane tracking), AIS (ship tracking), POCSAG (pagers), NOAA and GOES weather satellites (weather images), weather balloons, radiosondes, DAB radio, DVB-T video, Inmarsat, Iridium, and so much more!
- The best-performing low-cost RTL-SDR available anywhere! Compared with RTL-SDR v3, HF SNR is improved by up to 15dB, VHF & UHF SNR is improved by up to 6dB, tuning accuracy is improved by an average of 4x, and the frequency range is expanded all the way down to 100kHz
- v5 has a frequency capability of 100kHz to 1.75GHz and up to 3.2MHz of instantaneous bandwidth. HF reception below 25MHz is accomplished with direct sampling and requires a suitable antenna. We recommend using a Balun One Nine to make a DIY long wire or dipole antenna (sold separately, product ID B08HGSYB7R or B00R09WHT6)
- Though the direct sampling implementation of NESDR SMArt v5 is much better than any other RTL-SDR, we still recommend using an upconverter like the Ham It Up for a more fulfilling HF experience (sold separately, product ID B076CYK8XZ)
- Computer: A compatible host to run AIS-catcher, such as a Raspberry Pi, PC or Mac.
- Receiver: A supported SDR, dedicated receiver, or other supported input source.
- Antenna: A VHF antenna suited to AIS frequencies, approximately 162 MHz.
The project advises placing an outdoor vertical antenna high with a clear line of sight toward the water. It notes that antenna height and location can matter more than the receiver; this is setup guidance, not a tested range guarantee. No specific reception distance can be promised from the project’s published materials.
Which receiver should you use?
The right choice depends on whether you want a general-purpose SDR or a purpose-built AIS receiver, and on whether the required drivers and libraries work with your operating system. The project README lists RTL-SDR dongles, Airspy, HackRF, SDRplay and SoapySDR among supported receiver families. It also lists ZMQ, RTL-TCP and SpyServer among network or file input options. Check the current compatibility information before buying or following model-specific instructions.
Rank #2
- Turn your computer, phone or tablet into a radio scanner/ham radio receiver that can receive nearly all RF signals! Compatible with Windows, Mac OS, Linux, and Android
- NESDR SMArt RTL-SDR v5 can be used for the reception of broadcast AM radio, broadcast FM radio, shortwave radio, CB radio, public security radio, trunked radio, air traffic control, ACARS (plane-ground communications), ADS-B (plane tracking), AIS (ship tracking), POCSAG (pagers), NOAA and GOES weather satellites (weather images), weather balloons, radiosondes, DAB radio, DVB-T video, Inmarsat, Iridium, and so much more!
- The best-performing low-cost RTL-SDR available anywhere! Compared with RTL-SDR v3, HF SNR is improved by up to 15dB, VHF & UHF SNR is improved by up to 6dB, tuning accuracy is improved by an average of 4x, and the frequency range is expanded all the way down to 100kHz
- v5 has a frequency capability of 100kHz to 1.75GHz and up to 3.2MHz of instantaneous bandwidth. HF reception below 25MHz is accomplished with direct sampling and requires a suitable antenna. We recommend using a Balun One Nine to make a DIY long wire or dipole antenna (sold separately, product ID B08HGSYB7R or B00R09WHT6)
- Though the direct sampling implementation of NESDR SMArt v5 is much better than any other RTL-SDR, we still recommend using an upconverter like the Ham It Up for a more fulfilling HF experience (sold separately, product ID B076CYK8XZ)
| Option | Connection and configuration | Best fit |
|---|---|---|
| RTL-SDR dongle, including the RTL-SDR Blog V4 named by the project | USB SDR; requires a supported setup and device drivers or libraries for the host operating system. | Users who want a general-purpose SDR as well as AIS reception. |
| Wegmatt dAISy-catcher | The project describes it as a plug-and-play option that connects over serial, as a USB device or as a Raspberry Pi HAT. | Users looking for a dedicated AIS receiver rather than a general-purpose SDR. |
The project does not publish a controlled comparison of reception performance or reliability between these devices. Choose based on compatibility, connection type and intended use rather than assuming one will receive more vessels.
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How do you install and configure AIS-catcher?
Installation routes vary. Official setup materials cover Linux and Raspberry Pi, Windows, macOS, Docker, Android and source builds. The project also documents a browser-based setup wizard that helps select an input device and optionally enable output feeds. A device supported by AIS-catcher is not necessarily available through every installation route; verify the dependencies for your chosen platform in the installation overview and Getting Started guide.
Rank #3
- Includes 1x RTL-SDR Blog brand R860 RTL2832U 1PPM TCXO HF Bias Tee SMA Dongle (V3) (Dongle Only)
- Several improvements over other brands including use of the R860 tuner, improved component tolerances, a 1 PPM temperature compensated oscillator (TCXO), SMA F connector, aluminum shielded case with thermal pad for passive cooling, and an activatable bias tee circuit.
- Can tune from 500 kHz to 1.7 GHz and has up to 3.2 MHz of instantaneous bandwidth (2.4 MHz stable). (HF reception below 24 MHz in direct sampling mode with reduced performance). Please note RTL-SDR dongles are RX only.
- Please follow the quickstart guide linked in the included the manual for installation of the drivers and free software. Please feel free to contact us via Amazon messaging for technical support - we're happy to help
- Assemble the station: Connect a compatible computer, receiver and antenna. Follow the receiver’s platform-specific driver or library requirements.
- Install AIS-catcher: Choose an installation method listed for your operating system in the official installation overview.
- Open the control panel or use the command line: Follow the setup flow for your installation. In the browser wizard, select the input device that matches your receiver or source.
- Check for decoded messages: With a working input and received AIS broadcasts, decoded NMEA messages can appear locally or be sent to configured outputs.
- Configure forwarding only if needed: Enable the relevant feeds for the application or service you want to use; community sharing is optional.
How can you view or forward AIS data?
AIS-catcher produces NMEA messages for local display or forwarding. The repository describes UDP, HTTP and TCP outputs; the Quick Start’s configuration walkthrough also gives MQTT as an optional feed example. Which options are available depends on configuration. These outputs let other applications or services consume decoded messages without making AIS-catcher itself a navigation system.
Community data sharing is optional. The project describes station registration and a sharing key as prerequisites for contributing data. If you plan to make data publicly available, check the rules that apply where you live.
Rank #4
- A full, wide-band RF solution for those interested in getting started with software defined radio and with a keen interest in HF bands
- The NESDR SMArt HF Bundle utilizes a well-designed upconverter--the Ham It Up--to receive HF, NOT direct sampling hacks. This results in a vastly different HF experience--much better performance, and no loss of gain controls
- Included is a Ham It Up v1.3 upconverter, installed in a custom black aluminum enclosure; an NESDR SMArt RTL-SDR, 3 antennas, an impedance matching balun for longwire and dipole antennas, and interconnect adapters
- Proudly manufactured by NooElec in the USA and Canada, with a full 2 year product warranty on all bundle components and 24/7 technical support availability. Please contact our support team any time if you have questions!
- Amazon-exclusive bundle! Only available for a limited time
What is SDR?
A software-defined radio uses software to perform radio functions that would otherwise rely more heavily on dedicated hardware. In this setup, the receiver supplies radio input and AIS-catcher decodes AIS broadcasts. The computer, SDR and antenna therefore have distinct jobs: the antenna receives the signal, the radio hardware passes it to the software, and AIS-catcher processes it.
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Which antenna should you use?
The official Quick Start calls for a VHF antenna tuned to approximately 162 MHz. It recommends an outdoor vertical placement, mounted high and with a clear line of sight to the water when practical. Those recommendations do not establish a guaranteed range, and the project does not provide a measured comparison of antenna models.
Best Value
- Included: Nooelec USB dongle & antenna
- RTL2832U interface IC & R820T tuner IC on USB dongle
- These are custom USB devices tuned for SDR and include much better components than generics
- Full 1-year warranty & installation support available!
Is receiving AIS legal?
Rules for radio reception and redistributing received data differ by jurisdiction. AIS-catcher’s Quick Start advises checking local rules, particularly before publicly sharing data. Because the applicable requirements depend on location, consult the relevant local authorities or regulations rather than treating this as a universal legal determination.
I see no messages — what now?
Work through the station from the signal source toward the software output. A missing message can result from an input or configuration problem, or simply from no decodable broadcast reaching the station at that moment.
- Confirm the selected input: Check that the wizard or command-line configuration points to the receiver or network/file source actually in use.
- Check platform prerequisites: Make sure the receiver’s drivers and required libraries are installed for the operating system and installation method you chose.
- Review antenna setup: Confirm the antenna is suitable for approximately 162 MHz and connected as intended. Placement with height and a clear line of sight toward water follows the project’s guidance.
- Separate reception from forwarding: First check whether AIS-catcher decodes messages locally. If it does, troubleshoot the configured UDP, HTTP, MQTT or TCP destination separately.
- Allow for local conditions: The project does not promise a particular reception distance or vessel count; reception depends on the station and radio environment.
Important safety limitation
AIS-catcher is a hobby project, and its maintainers say it has not been tested and designed for reliability and correctness. The project disclaimer states: “DO NOT rely upon this software in any way including for navigation and/or safety of life or property purposes.” The documentation likewise says it is not approved for navigation or safety-of-life applications. Do not use it in place of certified marine navigation or safety equipment.
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