Gwyn Griffith's HamSCIence Zoom Presentation - Using GRAPE Data

[Gary Mikitin, AF8A]

From the HamSCIence Zoom call of 31 October:

High and Low Rays? Ionospheric Height Measurements on 8 April 2024 and Steps Along the Way, by Gwyn Griffiths G3ZIL

Zoom recording at https://www.youtube.com/watch?v=qcM5_IKjvw4

Gwyn paid numerous compliments to the GRAPE* ecosystem (hardware, software & the Central Control System).

Along the way, Gwyn covered many topics of relevance to than the HamSCI GRAPE community (further references are on Gwyn’s slides, those below are from my wonderings across the World Wide Web):

• How to read data, using Python, from the DRF (Digital Radio Format) files
• Autocorrelation - a commonly used method for analyzing time series data (here, Doppler shifts).  See https://www.ibm.com/topics/autocorrelation
• Multi-path propagation from WWV to W2NAF - explained using a ray trace diagram
• Calculating reflection height of HF signals
• Brief mention of ordinary vs extraordinary wave propagation https://www.ukssdc.ac.uk/ionosondes/ionosonde_basics.html
• The value of having a control station - actually, multiple control stations - receiving WWV only a few kilometers distant
• Impacts of antenna patterns on Doppler frequency spread analysis.  A lesson for future PSWS stations?
• Practical uses of PyLap ray trace simulations
• Frequency domain analysis (FFTs) of the Doppler shift data
• Using transforms (here, the Continuous Wavelet Transform) to identify specific signal characteristics in the data set (I couldn’t find a quick and easy explanation - this one requires some mathematics/statistics background:  https://www.mathworks.com/help/wavelet/gs/continuous-wavelet-transform-and-scale-based-analysis.html)
• Possible application of machine learning to these questions

73 de Gary, AF8A

*GRAPE - Great Radio Amateur Propagation Experiment

[Gwyn Griffiths]

If there is an interest I'd be more than willing to go through the material I presented at the Science telecon to a Grape telecon, perhaps in discussion mode rather than a continuous presentation.

73

Gwyn G3ZIL

[HETZAL HARTLEY]

I'd be very interested.

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[Dr. Nathaniel A. Frissell Ph.D.]

I think that would be most excellent, Gwyn. 

It would be very good to talk about there. 

73 de Nathaniel W2NAF 

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From: hamsci...@googlegroups.com <hamsci...@googlegroups.com> on behalf of HETZAL HARTLEY <het...@cox.net>
Sent: Monday, November 4, 2024 7:58:10 AM
To: Gwyn Griffiths <gxgri...@virginmedia.com>; 'Gwyn Griffiths' via hamsci-grape <hamsci...@googlegroups.com>
Subject: Re: [hamsci-grape] Re: Gwyn Griffith's HamSCIence Zoom Presentation - Using GRAPE Data

 

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