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Decoding James Webb Space Telescope

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Re: Decoding James Webb Space Telescope

#81

Post by aragilar »

londons_explore wrote: post #15
colechristensen wrote: post #9

Earlier quoted context omitted.

This is just telemetry data which doesn’t have much general or scientific interest, i guess they could publish the protocol spec (honestly it probably is aquirable) but most of the fun for the kinds of people who want this data is going to be doing this reverse engineering themselves. The real imaging data would require a much more significant dish to even receive (i can’t immediately find what it’s going to use, but…

But in a really open project, the design of the whole lot would be on the web, and the data sent back would be sitting on an FTP server somewhere for anyone to download and use. In many ways, an open project is cheaper to do than a behind-closed-doors project where every new contractor needs to get access to only the bits of the project they need access to, and misunderstandings happen because not everyone has enough…

The data will be at https://archive.stsci.edu/ (which holds the data from a whole host of space telescopes, and uses standard VO interfaces).

STScI is a major contributor to astropy etc. (https://github.com/astropy), and has their own space with more tools/software: https://github.com/spacetelescope.

It's unclear what else you'd actually want, unless you want to build a clone of the actual satellite (it wouldn't surprise me that a majority of the software for the satellite is open source, just not put together somewhere publicly for people to download).

Re: Decoding James Webb Space Telescope

#82

Post by colechristensen »

aragilar wrote: post #81
londons_explore wrote: post #15

Earlier quoted context omitted.

But in a really open project, the design of the whole lot would be on the web, and the data sent back would be sitting on an FTP server somewhere for anyone to download and use. In many ways, an open project is cheaper to do than a behind-closed-doors project where every new contractor needs to get access to only the bits of the project they need access to, and misunderstandings happen because not everyone has enough…

The data will be at https://archive.stsci.edu/ (which holds the data from a whole host of space telescopes, and uses standard VO interfaces). STScI is a major contributor to astropy etc. ( https://github.com/astropy ), and has their own space with more tools/software: https://github.com/spacetelescope . It's unclear what else you'd actually want, unless you want to build a clone of the actual satellite (it wouldn't s…

> It's unclear what else you'd actually want, unless you want to build a clone of the actual satellite (it wouldn't surprise me that a majority of the software for the satellite is open source, just not put together somewhere publicly for people to download).

Much satellite technology is classified or at least export controlled (ITAR). The major difference between a space telescope and a spy satellite is which direction you point.

Re: Decoding James Webb Space Telescope

#83

Post by jessaustin »

naikrovek wrote: post #79
dn3500 wrote: post #78

Earlier quoted context omitted.

It's not a technical restriction, it's a regulatory one. Like how parts of the UHF spectrum are allocated to TV and parts to radio. They don't want near earth communication going on in the deep space band because it will swamp the weaker signal.

right but the bands are not far apart, and the comment I originally replied to seemed to imply that there was significance that it was in the near space category rather than deep space. like it enabled something or was important in some unmentioned way. it was the whole (unspoken) point of the comment and I'm not "in the know" enough to already know the unspoken part. I'm asking what the unspoken part is.

According to the wiki link above, the bands are similarly sized and adjacent, so this wouldn't have much to do with "physics". Perhaps the "near" bands are just more congested?

Re: Decoding James Webb Space Telescope

#84

Post by seoaeu »

mhh__ wrote: post #64
ufmace wrote: post #37

Earlier quoted context omitted.

After seeing plenty of code and projects by people who weren't professional software engineers used to working on teams, part of the problem is likely that code written for this sort of thing often depends on a ton of dependencies and system-specific configuration bits that are documented poorly or not at all. Getting such projects to a state where a random person could git pull it and make sense of it and use it is…

(Argumentatively) I don't care. If I can't replicate your work you can't test it. If you make it clear it must be reproducible from the start and threaten to not publish if it can't be then they'll get in line - the kind of projects I'm thinking of are < 5k lines usually.

The only way to properly replicate a CS paper is to re-implement the code from scratch. Simply running someone's code again is most likely just going to give you the same buggy output they got (or just as likely a bunch of unrelated compile errors). But frequently, that isn't even what you want. Many CS papers are of the form "we were able to build software that does XYZ using this design", which isn't really a falsifiable statement in the first place. It just serves to give future researchers and practitioners data points they can use when building their own software

Re: Decoding James Webb Space Telescope

#85

Post by aunty_helen »

Thorentis wrote: post #47
aunty_helen wrote: post #29

Earlier quoted context omitted.

From: https://ntrs.nasa.gov/api/citations/20080030196/downloads/20... >To keep up with the high downlink, the recorder data gets sent directly to the Ka-band transmitter Currently aws groundstation doesn't support KA band so no luck there. It's apparently going to do a transmission once a day so you would need to time it right with the ground station.

Groundststion as a Service. I had no idea this existed. I am continuously amazed at how many things Amazon churns out "as a service".

It's pretty amazing. I found out about it a couple months ago from a job posting that wanted a programmer for a cube sat. It seems like this is what they're aiming the service for at the moment.

And really, it's the perfect place for aws to enter, add glue, and provide a service to let you do your core business. Feels like the future man.

Re: Decoding James Webb Space Telescope

#86

Post by aunty_helen »

hayanno wrote: post #48
aunty_helen wrote: post #29

Earlier quoted context omitted.

From: https://ntrs.nasa.gov/api/citations/20080030196/downloads/20... >To keep up with the high downlink, the recorder data gets sent directly to the Ka-band transmitter Currently aws groundstation doesn't support KA band so no luck there. It's apparently going to do a transmission once a day so you would need to time it right with the ground station.

Nice link, very informative, here's a funny excerpt : "It [JSWT] is currently planned to be launched in 2013 from French Guiana aboard an Ariane 5 launch vehicle".

I couldn't find a publish date in the pdf but going off the url I'm going to guess that it was from 2008.

It's a little bit annoying finding information about jwst as info could potentially be old and out of date. Another document that I read mentioned using XML as the database format because XML was an emerging standard :S

Re: Decoding James Webb Space Telescope

#88

Post by MAGZine »

colechristensen wrote: post #82
aragilar wrote: post #81

Earlier quoted context omitted.

The data will be at https://archive.stsci.edu/ (which holds the data from a whole host of space telescopes, and uses standard VO interfaces). STScI is a major contributor to astropy etc. ( https://github.com/astropy ), and has their own space with more tools/software: https://github.com/spacetelescope . It's unclear what else you'd actually want, unless you want to build a clone of the actual satellite (it wouldn't s…

> It's unclear what else you'd actually want, unless you want to build a clone of the actual satellite (it wouldn't surprise me that a majority of the software for the satellite is open source, just not put together somewhere publicly for people to download). Much satellite technology is classified or at least export controlled (ITAR). The major difference between a space telescope and a spy satellite is which direct…

A funny quip but the main imaging cameras on the jwst would be useless pointed at earth.

Re: Decoding James Webb Space Telescope

#90

Post by 8bitsrule »

zemb wrote: post #77
monocasa wrote: post #40

Earlier quoted context omitted.

Same as anything in amateur radio. There'll be a lot of hints at what you're doing from the shape of your broadcasts, and there's a lot of amateur radio enthusiasts that'll call the feds on you if they get a hint that you aren't following the rules.

radio enthusiasts are fans of the fed?

Here's an ARRL article from 11-2016 (re the shutdown of 11 FCC field stations) which details plans and motivations.

https://www.arrl.org/news/fcc-special-counsel-laura-smith-sa...

In a more recent post (which includes good suggestions for experimenters):

> The ham bands aren’t full of whacked-out haters looking to get rid of everybody else, but hams are very accustomed to people using the bands without a license or not following the band plans, causing interference problems.

https://thesilicongraybeard.blogspot.com/2020/09/a-ham-radio...

Usually the 'self-policing' by hams (it's usually very effective) is done gently. They get that the frequencies are free of $$cost, and don't want to lose (any more of) them.

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