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Above Earth Productions
A radio operator in headphones sits at a laptop showing a signal waterfall in a park at dusk, a tall lattice radio tower on the horizon.
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Project 04 / 06

In development

Long Path

A desktop console for software-defined radio receivers, built around two-antenna diversity reception.

Launching soon

At a glance

Platform
Mac, Windows and Linux desktop
Radios
Software-defined receivers
Reception
Two-antenna diversity with beam steering
Noise
Fingerprinting and cancellation in software
Foundation
An open-source radio console, with my own engine on top

Overview

Long Path is a desktop console for software-defined radio receivers, built for weak-signal work under modern noise. It aligns two antennas in time and phase and combines them into one stronger signal, steers a null onto interference, and fingerprints the noise of modern electronics, such as switching power supplies and LED drivers, so it can cancel it in software. It runs on Mac, Windows and Linux on top of an open-source radio console; the diversity and noise engine is my own.

What it does

  1. Diversity reception

    Combines two antennas, aligned in time and phase, into one stronger signal.

  2. Beam steering

    Aims its response at one station, or a null at a noise source, frequency by frequency.

  3. Noise fingerprinting

    Classifies interference by its signature and applies the countermeasure suited to each kind.

  4. Built for SDR

    For receivers that do their tuning and filtering in software.

The story

A signal from the far side of the world arrives faint, half lost in the noise. Long Path listens for it on two antennas at once and combines what they hear, so the weak ones come through.

How it’s built

Long Path is built for the hardest kind of listening, a faint station on the far side of the world buried under the electrical noise of modern life. It fingerprints that noise and removes it in software.

Noise fingerprinting
It samples the noise around a station and classifies it by signature, from the hum of switching power supplies and LED drivers to the clicks of an electric fence or a steady tone. Each class gets its own countermeasure.
Two-antenna diversity
Two antennas a short distance apart hear the same signal slightly differently. Long Path aligns the two in time and phase and combines them into one stronger signal.
Beam steering
By changing how the two antennas are mixed, it can aim its response at one station or steer a null onto a noise source, frequency by frequency.
Several decibels of lift
With the noise identified and nulled, the target is several decibels of improvement on a weak signal, which can be the difference between copying a distant station and missing it.
Built on open source
It runs on Mac, Windows and Linux and is built on an open-source radio console. The diversity and noise engine on top of it is my own.

Launching soon

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