[Ground-station] Ground-Station Digest, Vol 34, Issue 15

[Thomas Parry]

The ITU rain models are pretty straight-forward to implement and I already
have them baked into here:
https://github.com/phase4space/payload-dmt/blob/master/link-budget/DVB-Tool/SystemDefinition.py

It's simply a matter importing the ITUR module (+1 for Python) and
providing the right information.

Cheers,
Thomas

On Thu, 21 Jan 2021 at 19:50,
<ground-station-request at lists.openresearch.institute> wrote:

>
> Date: Thu, 21 Jan 2021 09:59:07 -0800
> From: Michelle Thompson <mountain.michelle at gmail.com>
> To: Salvatore Lionetti <salvatorelionetti at gmail.com>, Alan Rich
>         <arich127 at gmail.com>
> Cc: Michelle Thompson via Ground-Station
>         <ground-station at lists.openresearch.institute>
> Subject: Re: [Ground-station] Link budget
> Message-ID:
>         <
> CACvjz2WGGm+fGpu4p_RO014+KvzguNgqkgWZ2FJD-R_UWske+w at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Salvatore and Alan,
>
> I see the spreadsheet in the cloud instance, and am looking forward to
> hearing how this translates into Python.
>
> A tricky part of this is the required propa.dll. The ITU Rain Model in the
> spreadsheet uses macros. Some of these macros make use of a database, which
> computes rain, atmospheric and scintillation losses. This information is in
> a system file called propa.dll.
>
> I put the propa.dll in the repository with the spreadsheet here:
>
>
> https://github.com/phase4ground/documents/tree/master/Engineering/Link_Budget
>
> Here's instructions from Jan King:
>
> "You put this file into your WINDOWS10 machine (this thing won't work on a
> Mac) operating folder using the procedures in the Word file (also
> attached). Then reboot the machine; then install and open the Excel Link
> Model attached.  When you open this Excel as it is a .xlsm type file, it is
> suitable for using macros.  When you open the file it will prompt you by
> asking if you want to enable the macros.  Say YES."
>
> At that point the rain models work.
>
> We have two choices here. We can set the ITU Rain Model aside for now. Or,
> we can commit to converting the entire thing.
>
> "Working code is better than complete documentation". My goal here is to
> get working code, quickly. Then, review and evaluate. Setting aside the ITU
> Rain model for now and getting the rest done first is not a bad approach to
> start out.
>
> We do have to consider rain fade at the frequencies we are looking out.
> However, there is still a substantial amount of utility without the ITU
> Rain Model, and we are smart enough to understand the effect on margin.
>
> This is a substantial landmark spreadsheet. It will continue to be used,
> and to be useful, in its current form. This discussion is not an insult to
> the spreadsheet or anything like that.
>
> It will involve some effort to port to Python (Jupyter Notebook), but many
> hands make light work. The benefits of this work being in a Jupyter
> Notebook are numerous. The first one is that it eliminates the restrictions
> incurred by having to use propa.dll and Windows. The second is that there's
> every expectation that fixing bugs and testing this budget will become a
> *lot* easier. This work is well worth doing and appreciated.
>
> -Michelle W5NYV
>
>
>
>
> On Tue, Jan 19, 2021 at 11:12 AM Michelle Thompson <
> mountain.michelle at gmail.com> wrote:
>
> > Thank you very much Salvatore,
> >
> > There is no Octave code base that I know of, but this is a very good
> > direction.
> >
> > -Michelle W5NYV
> >
> >
> >
> >
> > On Sun, Jan 17, 2021 at 8:31 AM Salvatore Lionetti via Ground-Station
> > <ground-station at lists.openresearch.institute> wrote:
> >
> >> Hi guys,
> >>
> >> I'm sorry but I've started yesterday to work on this topic.
> >>
> >> I've made the spreadsheet available on my personal Nextcloud web
> instance:
> >>
> >> https://cumlaborare.strangled.net/s/Ng5H3RmmZP8HzNE
> >>
> >> By this way:
> >> * multiple people can collaborate on the same document, at the same
> >> moment.
> >> * comments are allowed,
> >> * versioning is in force.
> >>
> >> I've setup no password for now, but content can be recovered from a
> >> previous version very easily. (similar to Wikipedia)
> >>
> >> In the meanwhile I've verified that Jupyter can also use Octave
> >> interpreter, giving us the possibility to have a single code base.
> >>
> >> Is there a (also partial) Octave code base to reuse?
> >>
> >> Have a good day
> >>
> >
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