[HN Gopher] Keep Track: 3D Satellite Toolkit
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       Keep Track: 3D Satellite Toolkit
        
       Author : jonbaer
       Score  : 133 points
       Date   : 2024-09-30 08:10 UTC (14 hours ago)
        
 (HTM) web link (app.keeptrack.space)
 (TXT) w3m dump (app.keeptrack.space)
        
       | mihaaly wrote:
       | Nice concept! I only find it unintuitive to navigate, with button
       | panel of always truncated buttons looking strange, quasi-
       | permanent (requires action or stays there forever) and plenty
       | error messages that I am using it wrong ('select something
       | first!'), overly eager tooltips everywhere, with amusement
       | centric but impractical zoomed animation on click that is not
       | obvious how to reverse. It must be somewhere, the whole thing
       | looks rich in functions, but I lost interest in the tiring
       | entertainment centric approach before finding it.
        
         | Mochsner wrote:
         | I don't know what controls are, but is it by chance similar to
         | meshlab? The controls for it were quite good for a desktop 3D
         | navigator
        
           | thkru wrote:
           | Keyboard controls documentation:
           | https://docs.keeptrack.space/basic-tut/keyboard-shortcuts/
           | 
           | I mirrored Kerbal Space Program's controls where it made
           | sense, but for the most part they are original controls that
           | grew organically over time.
        
       | ricksunny wrote:
       | Neat! It's very cool to see what appears to be the 'hoop' formed
       | by all the geosync satellites. Yet then there appears to be a
       | 'cylinder' that contains the hoop whose axis is slightly off the
       | hoop's access. Any idea what that represents? By maintaining the
       | same distance from Earth as the geosyncs, they would seem to be
       | synchronous with a particular longitude, but would rise up & down
       | latitude above & below the equator with every revolution (i.e.
       | onr full cycle per day).
        
         | Sanzig wrote:
         | Geostationary satellites are required to maintain their
         | longitude (it's a license requirement to get their assigned
         | orbital slot), but not their inclination. Sometimes operators
         | will let the inclination drift a bit to save fuel.
         | 
         | Obviously it's a tradeoff, since if you let the inclination
         | change to a non-zero value the satellite will move around in
         | the sky. After a certain point it becomes unsustainable because
         | it will start to drift outside the receiving beam of your
         | customer's antennas.
        
           | ricksunny wrote:
           | All soundng very reasonabke so far, thank you - yet why is
           | the overall cylinder at an incline? If as you describe, why
           | wouldn't the choice of inclination be relatively random
           | across the entire population of only-somewhat-geosync
           | satellites? i.e. why isn't the cylinder satellate
           | constellation centered (and tberefore coaxial) about the true
           | geosync hoop?
        
             | thkru wrote:
             | The dead satellites sit at roughly 0 deg inclination
             | initially and then the moon causes their inclination to
             | shift. Depending on where the moon is in its orbit relative
             | to the satellite it can pull the argument of perigee
             | (lowest point) in different directions. The end result is
             | that the inclinations are all roughly between 0-20 degrees
             | but they all have different RAAN and argument of perigees.
        
               | ricksunny wrote:
               | Brilliant. As a result I'm reading up on graveyard orbits
               | and end-of-life perturbations from various celestial
               | sources. Also, this gem, whose longitude values _roughly_
               | correspond to what I 'm seeing:
               | 
               | last line of: https://en.wikipedia.org/wiki/Geosynchronou
               | s_orbit#Geostatio... :
               | 
               | "Geostationary satellites will also tend to drift around
               | one of two stable longitudes of 75deg and 255deg without
               | station keeping.[21]"
               | 
               | It cites SMAD, which on its face is more than good enough
               | for me, but since I don't have a copy handy, it would
               | still be interesting to know why those meridians would
               | represent particularly attractive ones to drift into.
        
       | razodactyl wrote:
       | Reminds me of Wall-E.
        
       | pookha wrote:
       | Very cool. Appreciate the comments for the mesh functions in the
       | source code...I've played around with photogrammetry but never
       | took the time to appreciate how the 3D polygon logic worked at a
       | low level (AliceVision).
       | 
       | And the UI is impressive but somewhat overwhelming. Could use a
       | UI tool to help better manage the pitch\yaw\roll of the globe or
       | individual vehicles\sensors (unless one already exists and I just
       | missed it).
        
         | thkru wrote:
         | I like the idea of a UI menu for controlling the camera - I
         | will add it to the to-do list.
         | 
         | Left click and drag to rotate pitch/yaw around the earth. Hold
         | shift to make it move slower. Middle mouse click and drag to
         | rotate the camera's pitch and yaw. Control + right click and
         | drag to pan up/down/left/right.
         | 
         | Common complaint is that the UI is overwhelming. I am open to
         | suggestions. I am thinking about building a separate subdomain
         | that disables many of the advanced features by default to make
         | it feel less daunting.
         | 
         | There are a lot of users with very different needs, so I
         | haven't come up with a good way to onboard new users without
         | making this look like every other globe with dots. There is
         | documentation https://docs.keeptrack.space/
        
       | bozhark wrote:
       | Want to use this with more layers of data
        
         | thkru wrote:
         | Can you elaborate on what you have on mind? Depending on what
         | you are looking for, I can add it to the to-do list.
        
       | theweblover007 wrote:
       | This is so amazing! Just a few fixes in the UX and it would be
       | even better than satvis.
        
         | thkru wrote:
         | Anything specific? Please throw your requests here or open an
         | issue on github
         | (https://github.com/thkruz/keeptrack.space/issues) and I will
         | try to get them implemented.
        
       | elintknower wrote:
       | Would be awesome to see the source for this tool! Also, I've
       | always been curious how you get applications like this to be
       | performant at higher resolutions without using GPUs or other
       | graphics tricks.
        
         | thkru wrote:
         | This is an open-source AGPL project:
         | https://github.com/thkruz/keeptrack.space It is using your GPU.
         | The performance is the combination of web workers, separating
         | the position buffers from the rest of the satellite data, and
         | not using any frameworks. That last one makes it run really
         | smooth, but means I am constantly trying to solve problems that
         | are already solved on threejs - camera controls for example.
        
       | alwinaugustin wrote:
       | I never expected there to be so many satellites orbiting Earth.
       | It feels like we've cluttered space with all these objects.
        
         | chrisdalke wrote:
         | Only appears that way because of the size of the icons
         | representing them (which at the base zoom level are kilometers
         | wide). If it was drawn at real scale the objects would be
         | insignificant.
        
         | exitb wrote:
         | At the same time, it appears that you could load all artificial
         | objects in Earth's orbit onto a single small container ship.
        
         | thkru wrote:
         | That is the objects that are big enough for us to track
         | somewhat reliably (10cm+). Based on models produced by ESA's
         | space debris office, it is estimated that there are 1 million
         | objects between 1-10cm and an 130 million objects between 1mm
         | to 1cm.
        
       | alnwlsn wrote:
       | What are all those Unknown JSC Vimpel objects in that one well-
       | defined orbit between LEO and geostationary?
        
         | thkru wrote:
         | Two separate breakups that have been reported by Russians.
         | Given the age and lack of regular tracking I have them listed
         | as a very low confidence on the accuracy of the exact current
         | location.
        
       | nikolay wrote:
       | So much trash!
        
       | h1fra wrote:
       | Once you understand all the gray points are debris it makes more
       | sense (header > layer icon)
        
       | qwertox wrote:
       | Awesome!
       | 
       | I noticed that there is another much-used orbit apart from the
       | round, earth-centered Geostationary Orbit, which is smaller, more
       | elliptical, off-axis and tilted.
       | 
       | It may be the Molniya Orbit [0] which is "is a type of satellite
       | orbit designed to provide communications and remote sensing
       | coverage over high latitudes [...] The name comes from the
       | Molniya satellites, a series of Soviet/Russian civilian and
       | military communications satellites which have used this type of
       | orbit since the mid-1960s."
       | 
       | Can anyone confirm this?
       | 
       | It appears to be full of JSC Vimpel satellites, which is "a
       | Russian defense industry leader" [1], but from randomly clicking
       | on the objects many are just debris.
       | 
       | [0] https://en.wikipedia.org/wiki/Molniya_orbit
       | 
       | [1] https://macvympel.ru/en/about/
        
         | dr_orpheus wrote:
         | I believe what you are probably looking at (I'm having trouble
         | loading it) is probably debris in the Geosynchronous Transfer
         | Orbit (GTO).
         | 
         | [0] https://en.wikipedia.org/wiki/Geostationary_transfer_orbit
         | 
         | Edit: I believe that you are looking at a group of debris that
         | is in an orbit close to GTO. This response [1] has a more
         | detailed answer.
         | 
         | [1] https://space.stackexchange.com/questions/48911/what-
         | events-...
        
       | iamwil wrote:
       | If you scroll down on the option, you can launch missile attacks
       | and see its trajectory.
        
       | analogwzrd wrote:
       | A user interface suggestion: I tried using the 'Find Satellite'
       | option and manually scrolling through all the options in the drop
       | down menu was a little tedious. Maybe allow a filter by typing
       | the first couple of letters?
       | 
       | Also, what are the US GPS satellites listed under? I saw Beidou,
       | GLONASS, and Galileo but I couldn't find the GPS satellites.
        
         | analogwzrd wrote:
         | Ah got it, there was a 'Constellation' option to find the GPS
         | sats.
        
         | thkruz wrote:
         | The GPS satellites bus is listed under GPS, GPS II, GPS IIA,
         | GPS IIF, and GPS IIR. It looks like a bug that the Payload
         | isn't showing up. I see one as GPS SVN 10. I may be only
         | showing payloads where there are at least 2 with the same name
         | - otherwise there would be a dropdown that is 30,000 long.
         | 
         | Love your suggestion to improve the search feature to be more
         | like the main search dropdown. Adding it to the list of to-dos
         | on the github issues.
        
       | kilohotel wrote:
       | There are a few iterations of this, I'm personally partial to
       | https://www.satcat.com/globe bc of all the other data available
       | on site
        
         | thkruz wrote:
         | Completely agree that their data graphs are second to none.
         | Celestrak used to be the standard for these kind of charts but
         | Kayhan is more intuitive. We have different market space. Their
         | satcat tool (great name) is for viewing singular things in the
         | catalog. I focus on showing relational data between sensors and
         | multiple satellites which isn't offered outside of AGI's STK to
         | my knowledge.
        
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       (page generated 2024-09-30 23:00 UTC)