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

[Michelle Thompson]

Thank you Thomas. That was the only tricky part that I saw.

-Michelle W5NYV




On Thu, Jan 21, 2021 at 11:46 AM Thomas Parry via Ground-Station
<ground-station at lists.openresearch.institute> wrote:

> 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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