GNU RADIO FOR SPACE RESEARCH

RUSTAM AKHTYAMOV

Research Assistant, Skoltech rustam.akhtyamov@skolkovotech.ru

23rd October 2015

SkoltechOn Conference, Skolkovo Institute of Science and Technology, Moscow

HARDWARE-DEFINED VS SOFTWARE-DEFINED RADIOS

Mathematical representation

eAM = (1 + mˑsin(ωmt)) sin(ωct)

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Audio AM

Mixer

Local

oscillator

sinωct

Coherent detector

A

D DSP

Analog to

Digital

Converter

Digital

Signal

Processor

Ideal SDR receiver

COMMERCIALLY AVAILABLE SDRS (STARTING FROM $10)

HackRF

USRP B210

BladeRF

RTL SDR dongle

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• GNU Radio is a software to perform the signal processing;

• It has a GUI to create signal processing applications by drag-and-drop.

Generate Python code and execute the code

Generate Python code

A port's colour indicates the type of

samples flowing through the port. The

colours also apply to block parameter fields.

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GNU RADIO FOR GROUND SATELLITE APPLICATIONS

• Images from NOAA weather satellites;

• Nano and pico satellites telemetry;

• Studying the Earth ionosphere.

[Image credit]: http://websterling.com/

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FEDERATED SATELLITES SYSTEMS APPROACH

[Image credit]: Lluch – an FSS architecting framework

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FSS NEGOTIATOR PROTOTYPE (OCTOBER 2015) Satellite emulator FSS negotiator Destination satellite

[Image credit]: Akhtyamov, Lluch, Golkar – SOFTWARE DEFINED RADIO IMPLEMENTATION OF A NEGOTIATOR NODE TESTBED FOR FEDERATED SATELLITE SYSTEMS 7

Receives and demodulates the signal, decodes AX.25 packets

Control script Stores the data and starts forwarding, when it is required

FSS NEGOTIATOR (RECEIVE, STORE AND FORWARD DATA)

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MONSTER PROJECT (APRIL 2015)

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MONSTER. EXPERIMENTAL SET-UP

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HAB2 32 km

Ceiling

Altitude

5 element Yagi on Celestron tracking

mount

Ping for status/ Receive broadcasts

HAB1

3kg platforms

6,6 m/s

Ascent Rate

Each HAB broadcasts its telemetry data comprising coordinates, altitude, time, and relays data from the other HAB upon receiving.

Tracking

Ground

Station (GS)

2 Stratospheric Balloons (HABs)

Transmitter script

File Source Packet Encoder GMSK Mod Polyphase Synthesizer Sink

MONSTER. GNU RADIO FLOW GRAPHS

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Receiver script

Source Xlating FIR Filter GMSK Demod Packet Decoder File Sink

CONCLUSION

• GNU Radio is widely used as an toolkit to create ground satellite applications. But it also can operate on embedded systems such as a Raspberry Pi 2, so the possible list of applications might be significantly broadened;

• Although GNU Radio is not very friendly for beginners at present, it is an open-source project, so it constantly evolves and might be much more convenient in the future thanks to efforts of thousands of people.

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