Implementation of an Ionospheric Echoes Receiver using an SDR with GNU Radio to obtain vertical and oblique ionograms

Abstract

The Jicamarca Radio Observatory (JRO) operates a vertical incidence pulsed ionospheric radar (VIPIR) dedicated to probing the equatorial ionosphere. This high-resolution system runs 24/7 and complements the suite of observations performed at JRO. As the VIPIR ionosonde operates with a wide beam antenna and reflected signals are dispersed at distances far as 1500 km, we have designed, built, and installed four new VIPIR receivers dedicated to oblique sounding. These receivers increase and expand the system's field of view and enable unique measurements, yielding new scientific results. This poster describes the Ionospheric Echoes Receiver (IER) by listing its components and detailing the different parts of the hardware and software elements. The receivers use a USRP N200 by Ettus and an acquisition flowgraph implemented in GNU Radio Companion. In addition, we present the OOT (Out Of Tree block), which generates the demodulation signal and changes its frequency value each Inter Pulsed Period. We also show preliminary displays of the vertical and oblique ionograms acquired using the Jicamarca VIPIR and the new receivers.