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> the photo illustrations used in the article are selected to make things seem worse than they really are Exactly. I do a LOT of astrophotography and satellite
by dheera 2y ago
> the photo illustrations used in the article are selected to make things seem worse than they really are
Exactly. I do a LOT of astrophotography and satellite trails are actually very easy to get rid of. Even the stupidest, most naive outlier rejection techniques, such as taking a stack of tracked images, finding their mean and standard deviation, throwing out any data points outside of 2 standard deviations, and then re-averaging, will get rid of the satellites very cleanly. You can go to more advanced techniques such as doing linear fits and RANSAC and whatnot, but you get the idea.
NOT doing any outlier rejection, just taking the mean of all the images will show the satellite tracks, but very dimly. The people who are trying to make noise on social media deliberately and disingenuously take the max() instead of the mean() to make the problem seem worse than it is.
That said -- in all of my imaging sessions, aircraft are a much, much, much bigger problem than satellites, and still easy to deal with. Yet nobody makes any noise about aircraft.
- malfist 2y agoSeriously, any time you have >3 images to stack satellites and planes are a complete non issue. The median pixel value is always going to exclude those. Five images is enough to eliminate any trails even if they overlap between images.
- nullc 2y agoYou're not imaging with cryogenic CCDs --- satellite trail can blow out whole rows.
- rblatz 2y agoJust do it in space and avoid the whole atmosphere and ground based light pollution. Space is cheaper than ever now, this is a problem for amateur astronomers, and hobbyists shouldn’t hold back progress.
- nullc 2y agoSpace imposes extraordinary costs and limitations which heavily precludes exploratory research. Instruments are built for space to achieve specific tasks which we know will be successful. Instrument development has to first occur on earth-- including the research that lets us know which things will yield results deployed in space. Astronomy aside, fleets of satellites once they turn to junk may eventually make further launching problematic.
- djao 2y agoSpaceX deliberately launches satellites into orbits which are too low to sustain on their own. Once the satellites run out of propellant, which happens after a few years of normal operation, they cannot remain in orbit indefinitely and eventually burn up in the atmosphere. On very rare occasions, a launch malfunctions in such a way that the satellites end up in unintended orbits that do turn into long-term junk, but this is not the norm.
- agos 2y ago"just do it in space" has got to be one of the best hacker news solution to other profession's issue I've ever read.
- mrguyorama 2y agoThis is equivalent to saying "Just do one percent the space science we do now" Where is SpaceX offering to put up a billion dollars worth of space observatories to offset their pollution of a public good?
- malfist 2y agoNo, I'm not, I'm using cooled CMOS sensors. CCD is ancient tech these days.
- nullc 2y ago> CCD is ancient tech these days. Their performance at cryogenic temperatures is quite good which is one reason why currently in design/construction scientific instruments are still using them. And in those instruments serious overload from shiny satellites is not just a little streak that can be easily excluded. https://www.aanda.org/articles/aa/full_html/2020/04/aa37501-20/aa37501-20.html https://www.aanda.org/articles/aa/full_html/2020/04/aa37501-...
- thayne 2y agoTaking pretty pictures, and collecting scientific data are very different. If a satellite is anywhere close to your target object in a frame you are using for photometry (measuring the amount of light), the frame is ruined, because it adds noise.