Ettus USRP and GNU Radio Simon Olvhammar Chalmers University of - PowerPoint PPT Presentation

Chalmers University of Technology Dicke-Switched microwave radiometry using Ettus USRP and GNU Radio Simon Olvhammar Chalmers University of Technology, Sweden Department of Earth and Space Sciences 1

Chalmers University of Technology Overview • Dicke-switching • Aeronomy and Astronomy • Software Defined Radio (SDR) platforms i.e The Ettus Universal Software Radio Peripheral (USRP) • GNU Radio • A Dicke-Switched Fast Fourier Transform (FFT) back-end • Measurements (O3 and CO) • Conclusion Department of Earth and Space Sciences 2

Chalmers University of Technology Dicke-Switching • Gain, atmospheric fluctuations • Robert H. Dicke • The Dicke Radiometer • Load, sky and frequency switching Applications - Search for ExtraTerrestrial Intelligence (SETI) - Interstellar medium - Dark Matter/Energy - Black holes - Atmosphere Department of Earth and Space Sciences 3

Chalmers University of Technology Department of Earth and Space Sciences 4

Chalmers University of Technology Department of Earth and Space Sciences 5

Chalmers University of Technology New Onsala 3mm band receiver V. Belitsky, I. Lapkin et al Department of Earth and Space Sciences 6

Chalmers University of Technology Software-defined radio (SDR) • Implement radio in software • Flexible • Cost effective • Simple • The Ettus USRP Department of Earth and Space Sciences 7

Chalmers University of Technology The Ettus USRP architecture Department of Earth and Space Sciences 8

Chalmers University of Technology • Blocks designed in C++ • E.g. IIR-filter, FFT-calculations • Linked through GRC, Python or C++ • Free and open source policy • Great community Department of Earth and Space Sciences 9

Chalmers University of Technology A Dicke-switched FFT spectrometer in GNU Radio Department of Earth and Space Sciences 10

Chalmers University of Technology Measurements of frequency-switched O3 and CO using a double side band heterodyne receiver Front-end Back-end P.Forkman et al Department of Earth and Space Sciences 11

Chalmers University of Technology Frequency-switched measurement of CO at 115.27 GHz and O3 at 110.84 GHz with Ettus USRP and GNU Radio as back-end spectrometer Department of Earth and Space Sciences 12

Chalmers University of Technology Summary and conclusions • Cheap, reliable high performing FFT spectrometer using SDR platforms and free software • Easily integrated in new or existing systems • Simple, cost effective, high performing • A global network of ground based stations • Atmospheric and interstellar measurements on a whole new scale! Department of Earth and Space Sciences 13

Chalmers University of Technology Department of Earth and Space Sciences 14

Chalmers University of Technology Department of Earth and Space Sciences 15