HFDL

Introduction

High Frequency Data Link (HFDL) is a data link in the high frequency range (3 - 30MHz) with virtually global coverage. HFDL is used to convey short data messages over long distances, bi-directonally between ground stations and aircraft using the propagation effect of high frequency radio waves.

16 ground stations provide redundant global coverage. There are 12 bands/groups of frequencies in the HFDL range (2 - 21MHz), and these are covered in more detail in the frequencies section below

Hardware

For a basic set up covering a couple of adjacent bands you can get up and running with a Raspberry Pi4, RTL-SDR v4 and a suitable HF antenna (e.g. MLA-30+). For more complete setups covering all bands all of the time a lot of CPU and USB bus bandwidth is required and a Raspberry Pi4/5 will not be sufficient in some usecases. (To be discussed further - WORK IN PROGRESS)

Software

Bare metal installation

  • dumpHFDL - a mature HFDL decoder. Installation instructions are found on the readme of the dumpHFDL github repo. There is also a step-by-step guide to installing SoapySDR for SDRPlay and RTL-SDR devices with instructions on installing dumpHFDL and setting up system services for auto start etc., which can be found here.

  • xng - a next-generation multi-decoder client for SDRs, written in Rust for Linux, Windows, MacOS.

Docker installation

  • SDR-Enthusiasts (SDR-E) docker-dumphfdl - a docker wrapper for dumphfdl with a built in auto frequency selector or manual frequency selection. Assumes some prior knowledge of using SDR-E docker containers and some familiarity with using soapySDR (no soapySDR installation required).

Frequencies

12 Frequency bands

2, 3, 4, 5,6, 8, 10, 11, 13, 15, 17, 21.

Not all bands are active all the time and not all frequencies within the bands are in use. Consult the latest system table for current frequencies. (WORK IN PROGRESS)

version = 52;
stations = (
{ id = 1; lat = 38.384587; lon = -121.759647; frequencies = ( 21934.0, 17919.0, 13276.0, 11327.0, 10081.0, 8927.0, 6559.0, 5508.0 ); name = "San Francisco, California"; },
{ id = 2; lat = 21.184428; lon = -157.186846; frequencies = ( 21937.0, 17919.0, 13324.0, 13312.0, 13276.0, 11348.0, 11312.0, 10027.0, 8936.0, 8912.0, 6565.0, 5514.0 ); name = "Molokai, Hawaii"; },
{ id = 3; lat = 63.847168; lon = -22.455754; frequencies = ( 17985.0, 15025.0, 11184.0, 8977.0, 6712.0, 5720.0, 3900.0 ); name = "Reykjavik, Iceland"; },
{ id = 4; lat = 40.881922; lon = -72.63762; frequencies = ( 21931.0, 17919.0, 13276.0, 11387.0, 8912.0, 6661.0, 5652.0 ); name = "Riverhead, New York"; },
{ id = 5; lat = -37.015757; lon = 174.809637; frequencies = ( 17916.0, 13351.0, 10084.0, 8921.0, 6535.0, 5583.0 ); name = "Auckland, New Zealand"; },
{ id = 6; lat = 6.937536; lon = 100.388451; frequencies = ( 21949.0, 17928.0, 13270.0, 10066.0, 8825.0, 6535.0, 5655.0 ); name = "Hat Yai, Thailand"; },
{ id = 7; lat = 52.744089; lon = -8.926752; frequencies = ( 11384.0, 10081.0, 8942.0, 8843.0, 6532.0, 5547.0, 3455.0, 2998.0 ); name = "Shannon, Ireland"; },
{ id = 8; lat = -26.129658; lon = 28.206078; frequencies = ( 21949.0, 17922.0, 13321.0, 11321.0, 8834.0, 5529.0, 4681.0, 3016.0 ); name = "Johannesburg, South Africa"; },
{ id = 9; lat = 71.25849; lon = -156.577447; frequencies = ( 21937.0, 21928.0, 17934.0, 17919.0, 11354.0, 10093.0, 10027.0, 8936.0, 8927.0, 6646.0, 5544.0, 5538.0, 5529.0, 4687.0, 4654.0, 3497.0, 3007.0, 2992.0, 2944.0 ); name = "Barrow, Alaska"; },
{ id = 10; lat = 35.032377; lon = 126.238644; frequencies = ( 21931.0, 17958.0, 13342.0, 10060.0, 8939.0, 6619.0, 5502.0, 2941.0 ); name = "Muan, South Korea"; },
{ id = 11; lat = 9.084681; lon = -79.373969; frequencies = ( 17901.0, 13264.0, 10063.0, 8894.0, 6589.0, 5589.0 ); name = "Albrook, Panama"; },
{ id = 13; lat = -17.671199; lon = -63.157088; frequencies = ( 21997.0, 17916.0, 13315.0, 11318.0, 8957.0, 6628.0, 4660.0 ); name = "Santa Cruz, Bolivia"; },
{ id = 14; lat = 56.152603; lon = 92.583337; frequencies = ( 21990.0, 17912.0, 13321.0, 10087.0, 8886.0, 6596.0, 5622.0 ); name = "Krasnoyarsk, Russia"; },
{ id = 15; lat = 26.308529; lon = 50.472318; frequencies = ( 21982.0, 17967.0, 13312.0, 10030.0, 8885.0, 6646.0, 5544.0, 2986.0 ); name = "Al Muharraq, Bahrain"; },
{ id = 16; lat = 13.488833; lon = 144.828233; frequencies = ( 21928.0, 17919.0, 13312.0, 11306.0, 8927.0, 6652.0, 5451.0 ); name = "Agana, Guam"; },
{ id = 17; lat = 27.960945; lon = -15.405608; frequencies = ( 21955.0, 17928.0, 13303.0, 11348.0, 8948.0, 6529.0 ); name = "Canarias, Spain"; }
);

Useful links

PreviousVDL-M2NextDocker

Last updated