Pharlap/Pylap

[Robert Hipple]

Hi All,

I watched two presentations from the HamSCI Workshop 2022 about Pharlap and Pylap and would like to get this code running. The last activity on the Github repository Hamsci/Pylab is from 2025 and I thought I would check to see if anybody is currently working with this software so I can avoid reinventing any wheels.

Thanks,

Robert KE8UQV

[Kornyanat Hozumi]

Hi Robert,

Welcome to the group. Our working group is still in its early stages, and we do not yet have many members on this mailing list. However, quite a few people in the broader HamSCI community are using PyLap and PHaRLAP.

I am personally more active with PHaRLAP, but others may be able to provide more specific guidance on PyLap.

Could you elaborate a little more on what you would like to do with the software and what kind of setup or application you have in mind? That will help us point you toward relevant resources or connect you with people who may be working on similar topics.

Best regards,

Kukkai

---------------------

Kornyanat Hozumi (Kukkai), Ph.D., KM7GYX

Research Scientist

Department of Physics and Engineering

University of Scranton

From: hamsci-ra...@googlegroups.com <hamsci-ra...@googlegroups.com> on behalf of Robert Hipple <hipp...@gmail.com>
Date: Monday, July 27, 2026 at 6:23 PM
To: HamSCI Ray Tracing <hamsci-ra...@googlegroups.com>
Subject: Pharlap/Pylap

WARNING: This message originated from a source outside of the university.

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[Gwyn Griffiths]

Hello Robert

I am a PyLap user, and have been for some years. It can be got going for a new user based on the Manual Setup instructions at https://github.com/HamSCI/PyLap but please do read the entries on the Issues tab. In particular that the current PyLap will not work with recent PHaRLAP releases, it needs 4.5.0. What I suggested to a recent new user to consider was that they obtain the latest PHaRLAP from the official source, hence making an agreement to abide with terms and conditions, but not use that release, instead find  a copy of version 4.5.0. If you cannot find one on the PHaRLAP site then please message me.Be sure to alter lines in the manual set up that refer to version number.

Be prepared for problems. You may need to install in a protected environment. You will certainly need to obtain and install two updated indices files for the IRI models. Fellow HamSCI member Bob N6RFM has written a python script to help with that task. but I can't see it on his GitHub site.

I can try and help with any issues that arise.

regards

Gwyn G3ZIL

[Bob WB0VGD]

Hi Kukkai,

Glad to meet you. I have been working on HF channel sounding of the ionosphere for the past two years and am seeking ways to validate measurements for selected point-to-point radio links. I believe ray tracing should be a viable way to validate channel measurements and provide insight into radio path characteristics.

I run Windows 11 and have purchased the Matlab home edition. I downloaded PHaRLAP 4.7.4 and can get it to run in Matlab 2024b, but not Matlab 2025b. I noted that PHaRLAP 4.7.4 was compiled in 2024b.

One of my big frustrations is the lack of documentation beyond comments in the code itself. I have seen several YouTube videos on this code, but they do not address basic use, only advanced topics. It would be helpful if someone could write a basic user manual explaining how to configure PHaRLAP, the workspace variables, and the setup parameters. Currently, I am using "black box" experiments to use the code and am unsure of the accuracy of my results. This is hit or miss :-)

I have intercompared PHaRLAP with Proplab Pro 3.2 and obtained similar results, although Proplab uses the older 2007 IRI. I tried an intercomparison on selected paths in the 474 kHz (630 m) ham band and noted that rays were not returning to the ground with some of the PHaRLAP simulations. In the Proplab simulations, the rays always returned to the ground and the solutions were stable. I still do not understand enough about PHaRLAP yet to ensure I have configured it correctly.

A tutorial on the use of PHaRLAP would be a great contribution to the community. I hope to learn more about PHaRLAP in this working group.

73s Bob Johnk

Bob Johnk

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[Robert Hipple]

Kukkai,

I was looking at the the hamsci.org/working-groups and the Ray Tracing  and Scientific Modulation groups caught my eye. Learning Pharlap seemed like a great way to get involved, and Pylap was even better since I no longer have access to a Matlab license. I have been interested in signal propagation through dispersive media for some time now, so a lot of what Hamsci does is of interest to me.

I remain a member of the MSUARC and am always looking for new projects to engage the students. Every fall we get a new crop of students with new interests!

 

Thanks,

Robert KE8UQV

[Robert Hipple]

Hi Bob WB0VGD,

I was wondering about documentation myself. The Pharlap website says that there is ample documentation in the MATLAB help, but since I don't have MATLAB, I can't see that. Since I am learning it from the ground up, I could easily write down my steps and thereby lay the framework for some documentation.

73,

Robert KE8UQV

[Robert Hipple]

Thanks, Gwyn G3ZIL for the heads up. I downloaded the latest version of the Pharlap black box without realizing the limitations you mentioned. Are older versions of Pharlap available for download, or did you simply keep the older version that you have?

Robert KE8UQV

[Bob WB0VGD]

Hi Robert:

Thanks for your response...much appreciated. 

73s Bob WB0VGD

หากต้องการดูการสนทนานี้ โปรดไปที่ https://groups.google.com/d/msgid/hamsci-ray-tracing/1ccb97d0-bfc1-4131-9d21-926e0f15fbbfn%40googlegroups.com

[Kornyanat Hozumi]

Hi Bob WB0VGD, Robert KE8UQV, All,

I also learned PHaRLAP largely on my own, including how to configure the parameters and run simulations from scratch. I could therefore prepare a simple “how-to” guide covering the installation and basic use of PHaRLAP for a few specific applications. It sounds like this would be helpful, so I will consider putting something together. Also, I have been using PHaRLAP 4.5.3 and it’s still working great. So I, personally, want to stick with this version for a while.

Bob, your work on HF channel sounding and validating measurements for selected point-to-point radio links sounds highly relevant to this working group. Ray tracing should be a useful tool for this type of validation. We can discuss your work further during a Zoom session. Once I determine a suitable time for a working group meeting, I will circulate the details to the group.

Please also note that our working group plans to develop an open-source ray-tracing tool in the future. I hope it will be useful to the community and easier to install and use.

Also, is anyone planning to submit ray-tracing-related work to the AGU Fall Meeting? The broader HamSCI community is currently collecting information for the “HamSCI at AGU26” planning. Please add your information there if you plan to attend, even if you are not currently planning a ray-tracing presentation. We may be able to organize or support some presentations relevant to our working group. I also want to hold a casual meeting of those who are interested in the HamSCI ray tracing working group too

73,

หากต้องการดูการสนทนานี้ โปรดไปที่ https://groups.google.com/d/msgid/hamsci-ray-tracing/1ccb97d0-bfc1-4131-9d21-926e0f15fbbfn%40googlegroups.com

[gwyn griffiths]

Hello Robert

I have put a zip folder of version 4.5.0 on my Dropbox at 

https://www.dropbox.com/scl/fi/sp6tl5yzanhk8nmgr25uy/pharlap_4.5.0.zip?rlkey=vn1xtg3ry8lw6x0oqbhktu8n8&dl=0

Please let me know when you have downloaded this file and I will then remove.

As for what can be done with PyLap, I have some examples of how it can be run in an automated mode to obtain time series of various parameters, see my notes and access to python code at https://github.com/g3zil/grapeDRF_doppler_model if you scroll down to the section: G3ZIL Synthetic spectrograms

73

Gwyn G3ZIL

[Robert Hipple]

Thanks, Gwyn for the download and the github link! I am deep in getting Pylap to work on my ubuntu and appreciate any advice I can get.

Robert KE8UQV

[Robert Hipple]

Hi  Kukkai, KM7GYX,

A "how to" guide would be great, since the github documentation has not been updated since the student completed his thesis.

Kristina Collins put out a request topics of interest for AGU. She said that the deadline for abstracts was very near, and I did not want to miss that deadline so I indicated that I would be interested in submitting and presenting ray-tracing work. However, I have only been with Hamsci for about a month and would be interested in joining with anybody that might already have work in progress that I can help with.

73, Robert KE8UQV