Category: Airband

dumphfdl: A Multichannel HFDL Decoder for SDR

Thank you to Tomasz Lemiech for writing in and sharing with us the release of his new software "dumphfdl". Tomasz is the author of dumpvdl2 and also maintains RTLSDR-Airband. Regarding dumphfdl Tomasz writes:

dumphfdl is a multichannel HFDL decoder for Linux. HFDL (High Frequency Data Link) is a protocol used for radio communications between aircraft and a network of ground stations using high frequency (HF) radio waves. Thanks to the ability of short waves to propagate over long distances, HFDL is particularly useful in remote areas (eg. over oceans or polar regions) where other ground-based communications services are out of range. While many aircraft carriers prefer satellite communications these days, HFDL is still operational and in use.

Available HFDL decoding applications typically run on Windows and take an audio signal on input. The signal has to be delivered to the decoder via a physical cable from an external shortwave receiver or via a virtual cable from an SDR. This makes these apps inherently single-channel. This shortcoming does not apply to dumphfdl which interfaces directly with the SDR, so no pipes or virtual audio cables are needed. The program can decode multiple HFDL channels simultaneously, up to available CPU power and SDR bandwidth (there is no fixed channel count limit).

dumphfdl uses SoapySDR library ( to communicate with the radio. Any HF-capable receiver for which a SoapySDR driver exists, should work. I have tested it briefly with an RTL-SDR v3 dongle in direct sampling mode. While I had a bit of a success with it, HFDL signals are often quite weak, so a real HF radio (like SDRPlay RSP1A or Airspy HF+) gives much better results (more decoded messages).

The program may log decoded messages to a file or send them over the network for external processing and storage.

HFDL messages often contain diagnostic data accompanied with aircraft position information. The program may extract this data from decoded messages and provide a positional data feed for external plane tracking apps (eg. Virtual Radar Server). An example screenshot from VRS is attached - taken after about 2 hours of decoding eight HFDL channels spread across three HFDL subbands: 6.6, 8.9, and 10.0 MHz with two dumphfdl instances on two radios - RSP1A and Airspy HF+. Definitely a nice way to expand the coverage of a home ADS-B radar :-)

Refer to the file in the project repository for more details. The program is still under development, so new features and further improvements might be expected in subsequent releases.

dumphfdl - decoded aircraft positions plotted on a map

SDRUno 1.41 Released: Scheduler and ADS-B Plugins Added

Last week SDRplay released version 1.41 of their SDRUno software platform. SDRuno is the official software for the SDRplay line of low cost software defined radio devices. The main new feature is the addition of the scheduler facility which allows users to easily schedule recordings. This is great if for example you wish to automatically record a shortwave programs playing overnight.

SDRuno V1.41 was fully released today. It includes the much requested full scheduler facility which allows you to set up numerous recording events for your RSP. As well as providing all the expected calendar options (time of day, date, start and stop times, repeating options and so on), you can also set the ‘profile’ for each recording – this allows you to pre-set frequencies, bandwidths, demodulator options (AM/FM/USB/LSB etc.), choice of filters and antenna port selection. Additionally you can choose the settings for connectivity to other third party software or the running of a specific plugin.

Introduction to SDRuno 1 41 - Scheduler & Profiles (VID597)

The new version also includes a finalized version of their ADS-B aircraft tracking plugin. Last month TechMinds tested the ADS-B plugin beta, noting that it worked well, but there were bugs with the built in mapping feature. In the official tutorial video the ADS-B plugin is demonstrated and shows that the mapping problem is fixed.

SDRuno ADSB Plugin (VID599)

Simple FM Radio and Airband RTL-SDR Android Applications

On the Google Play store developer Knowle Consultants have recently released a new free application called "FM Radio (RTL-SDR)". This is a simple app that allows you to use a connected or remotely networked RTL-SDR to tune into preset broadcast FM stations. People wishing to use an Android enabled head unit in their car may be interested in the app as it makes tuning into broadcast FM stations easy just like it is on a standard radio.

They also have a similar app called "Airband Radio (RTL-SDR)" which provides a similar simple interface for tuning into airband presets.

Knowles Consultants simple Android RTL-SDR FM and Airband Receiver Apps

TechMinds: Testing the SDRUno ADS-B Plugin Beta

This week on the Tech Minds YouTube channel Matthew tests out the SDRuno ADS-B aircraft tracking plugin beta. SDRuno is the official software for the SDRplay RSP line of receivers, and the beta can be downloaded from their website (note the plugin will not work for the RTL-SDR).

In the video Tech Minds shows how to set up SDRuno to work on his active ADS-B antenna by activating the bias tee, and how to load and activate the ADS-B plugin. He goes on to show how you can then use another program called Virtual Radar Server to connect to the ADS-B plugin data output, and plot local aircraft on a map.

He notes that the plugin itself will have it's own map display available via a web browser, however in the current beta the mapping output is incorrect.

SDRPLAY SDRUno ADSB Plugin - Tracking Aircraft Easy

Decoding HFDL ACARS with a WebSDR and PC-HFDL

In the previous episode Rob from the Frugal Radio YouTube channel showed us how to decode HF ACARS using PC-HFDL and an HF capable SDR such as the Airspy HF+. In that episode he mentioned that it is possible to decode HF ACARS using a WebSDR as well.

In this weeks episode, Rob shows us how to do just that, making use of WebSDR receivers and the PC-HFDL software. Like the previous episode we see how to plot the aircraft HF ACARS position data on Google Earth and how to read and interpret some example messages received.

Decoding HFDL ACARS with a WebSDR and PC-HFDL

Dump1090 now Available as an Android App

The company ebcTech who makes AIS Share for Android has recently come out with a new app which is an Android App version of Dump1090. Dump1090 is a popular command line based ADS-B decoder for RTL-SDR dongles which allows you to receive and plot the locations of nearby aircraft on a map.

The app directly accesses the RTL-SDR via a USB OTG connection and provides a list of aircraft with image lookup, and a Google map display. The app is free however there is a message limit on received aircraft which can be unlocked via a low cost in-app purchase.

The author also wrote in and wanted to make a note about a special feature "In the app you can add Airport layers – This consist now 4480 Airports – most of them with corresponding homepage address / or Wikipedia link."

Dump1090 Android App

Frugal Radio: HFDL HF ACARS Decoding Tutorial

In Rob's latest episode of his excellent aviation communications series on his Frugal Radio YouTube channel he shows how to decode aircraft HF ACARS (HFDL) using a software defined radio. HFDL is short for "high frequency data link", and is a method aircraft use for sending text and data communications to ground stations. It is an alternative to VHF or satellite ACARS communications methods.

In the video he shows how he's been able to receive HFDL from all over the world using a simple HF dipole antenna and an Airspy HF+ Discovery. He goes on to show how to find HFDL signals, and how to decode signals using SDR# and the PC-HFDL software. Finally he shows examples of aircraft received, and how to interpret some of the information being received, including location information.

How to decode HF ACARS (HFDL) free with your SDR - Monitoring Aviation Communications Episode 8

Dump1090 with HackRF Windows Support

Thank you to Egor for writing in a sharing his work on modifying dump1090 in order to support the HackRF on Windows. dump1090 is software that is often used with RTL-SDR dongles for decoding ADS-B data for aircraft tracking. He writes:

Some time ago I was looking for dump1090 version with HackRF support that could work on Windows. But I have not found such version.
So I forked Malcolm Robb's version of dump1090 that could be built on Windows around 7 years ago. :) I've updated it and have added HackRF support from Ilker Temir's fork.
Now my version is available here The main difference from the others that it supports HackRF One device on Windows.