VMA Radio Lab Extends DecSAT Into a Multi-SDR Receiver

VMA Radio Lab, a software-defined radio application by Vitor Martins Augusto, has been extended into a receiver that can run several software-defined radios at the same time. The project is a fork of DecSAT, the satellite receiver originally written for the HackRF One, and it keeps that project’s broad ambitions while adding a capability DecSAT never had: parallel operation of multiple radios, each with its own tuners. The result is a single Windows application that can watch several slices of spectrum at once, from satellite downlinks to broadcast radio and television.

From one radio to several

The headline change is multi-SDR support. VMA Radio Lab can drive several radios in parallel, giving each one independent virtual tuners, known as VFOs. Supported hardware covers the usual bench of software-defined radios: HackRF, PlutoSDR, the USRP B210, RTL-SDR dongles, the SDRplay RSP1 and Airspy. One radio can be set to a wideband sweep, for example the full 950 to 2150 MHz satellite intermediate-frequency band, while another watches a narrow channel somewhere else entirely. The radios share one interface, so the operator works with the spectrum rather than with a collection of separate programs.

What it can receive

The range of signals is wide. The program handles DVB-T and DVB-T2 terrestrial television, DAB and DAB+ digital radio, and TETRA trunked radio, drawing on the companion decoders DecDVB-T, DecDAB and DecLAB. It also receives analogue radio and PAL colour television, complete with teletext, and it includes a vectorscope and a transport stream analyser for checking signal quality. Support for CrazyScan-compatible TBS tuner cards adds LNB power control and hardware DVB reception. Taken together, the list covers most of what a monitoring station or a broadcast engineer would want to see.

Notes on hardware and licensing

Not everything is plug and play. Listening to TETRA audio needs a separate ACELP codec library, which is distributed on its own for licensing reasons. Decoders for AIS ship tracking and ACARS aircraft messages are still experimental. The original DecSAT had already added support for the Fobos SDR, Airspy receivers and networked IQ streams over rtl_tcp, and those capabilities carry over. The software is released under the GPLv3 licence, with a 64-bit Windows build and a source archive available from the project site at vma-broadcast.com.

Why it matters

Tools like VMA Radio Lab matter because software-defined radio has become the working end of spectrum monitoring, and spectrum monitoring is the working end of drone detection. A receiver that can run several radios at once lets one operator watch a wide band for new signals while keeping a close eye on a channel of interest, which is exactly the pattern that counter-drone and electronic warfare work demands. Open, multi-radio tools lower the cost of that kind of watching, and they put professional-grade reception within reach of small teams.

Source: RTL-SDR.com