Advanced Digital Ionosphere Sounder

Ionorde 4 is an advanced high frequency radar which monitors Earth’s ionosphere by transmitting vertical pulses and precisely measuring the reflected signals parameters. It utilizes high technology hardware in conjunction with accurate and fast data processing techniques in order to remote sense of ionosphere. This low-cost and efficient scientific instrument extracts real time ionospheric condition and parameters from received signals by doing robust and precise measurements and calculations. Its compact and low weight Tx/Rx structures and easy to use software make it efficient and distinctive. Furthermore, unlike similar systems, it gives researchers a wide variety of options to select transmitted pulse waveform parameters such as amplitude, bandwidth, modulation, duty cycle and etc.



  • Accurate measurement of ionosphere reflected signal parameters: Amplitude, phase, delay, wave polarization, Doppler frequency and angle of arrival.
  • Real-time monitoring of ionospheric plasma characteristics
  • Collecting a compact database of ionospheric parameters to develop or improve the reliability of prediction models
  • Continuously observing and studying ionospheric structure and dynamics
  • Travelling Ionospheric Disturbances (TID) detection and characterization

Main Features

  • A complete but compact pulsed radar with selectable transmitted pulse waveform parameters
  • High height and Doppler resolution measurements capability
  • Improved received signal to noise ratio by coherent integration of coded pulses and using efficient antennas
  • User-friendly graphical user interface capable of control and supervision of the system

Hardware Specifications

  • Dual transmit-receive polarization (Linear or RHP/LHP)
  • Antenna arrester and spark gap discharge devices used as lightning protections
  • Operator-selectable transmitting power 10~200 Watts
  • High precision self-calibration setup
  • High quality tunable band-selection filters for Interference rejection
  • Portable active crossed loop antenna for receiving and separating the reflected RHP/LHP signals
  • 4-channel digital board with high-speed 16-bit A/D convertor
  • Built-In Test Equipment (BITE)
  • 9U Rack size
Figure 1: Ionorde4 Transmit antenna

Processing Specifications

  • More than 35 dB SNR gain achieved by coherent integration and pulse compression techniques
  • Interference Rejection up to 35 dB using RFIM
  • Take advantage of image enhancement methods for ionogram interpretation
  • Efficient and easy to use display
  • Real-time electron density extraction from ionogram
  • Doppler processing and ionospheric dynamic characterization
  • Compatible with SAO software and stadard ARIST5 package for ionogram analysis and scaling
Figure 4 Ionorde4 Software
Figure 6 Profilogram
Figure 7 Ionogram Interpretation Comparison: Ionorde4 with ARTIST5
Figure 8 Consecutive Ionograms