Ionosonde: Digisonde Portable Sounder 4D (DPS4D)

Last modified at Dec 18th, 2024, 13:02 GMT

Description

Digisonde Portable Sounder 4 Digital (DPS4D) is the fourth-generation instrument in the Digisonde family of ionosondes. In comparison to the previous DPS4 model, it uses direct RF sampling and a 4-channel digital 16-bit receiver chip and implements DSP-board functionality in the pre-processor FPGA. DPS4D accomplished superior precision of its signal timing and processing, allowing reliable Digisonde-to-Digisonde (D2D) synchronized operations. DPS4D is currently in production; total 52 units were built from 2006 to 2022.

Operational Modes

  • Scanning Ionogram

    ionogram
    Description
    The system steps through frequencies according to the selected program, transmitting and coherently integrating (a full spectrum, i.e. FFT, Doppler integration) a stream of N pulses. Just prior to transmission on each frequency four possible operating frequencies are monitored for interference/occupancy and the quietest is selected for the measurement. Then a few trial pulses are transmitted to allow automatic adjustment of receiver gain. As each coherent integration of pulse streams in completed, the raw output (i.e. 128 color coded amplitudes representing echoes at 128 heights) is added to the display of the developing ionogram. After all frequency steps have been completed the raw ionogram (16 complex Doppler lines at 256 heights and M frequency steps) is written out to a disk file and the automatic scaling program ARTIST (Automatic Real-Time Ionogram Scaler with True height analysis), is invoked and a file of automatically scaled parameters is created and displayed.

  • Drift Ionogram

    drift
    Description
    This is similar to the Doppler Ionogram in that higher Doppler resolution is achieved by extending the integration period. In addition to multiplexing frequencies the receive antennas are also multiplexed. This provides a raw data file which records the relative phase of all Doppler lines of all echoes on the four antennas in the receiver array, giving the angle of arrival of the individual echoes.

  • Digisonde-to-Digisonde fixed-frequency sounding

    D2D
    Description
    This is a fixed-frequency high Doppler resolution oblique-incidence sounding mode developed specifically for detection of the Traveling Ionospheric Disturbances (TID) based on harmonic analysis of the time series of the signal's Doppler frequency and angle of arrival variation.

Further Information and Resources

Resources

Metadata Information
Editor Borealis Global Designs
Version 1
Created Thursday 25th April 2013, 14:00
Last Modified Wednesday 18th Dec. 2024, 13:02