I wrote this long note, and then got too tired to finish. There is no apparent way to save a draft. I started out just talking about global networks of cameras for astronomy and other purposes. Then hinted at the social value of every person in the world being able to access the sky above them with a decent quality all sky camera. I live in Houston, and Houstonians seldom see the stars. But a city this large ought to be able to afford some sky cameras so that any person and all the classes at every level could look at the sky. Taking that to the limit a geosynchronous sky cam could show Houstonians what the real sky looks like any time.
But then I was trying to explain why I am looking at noise in camera sensors. And the story is too long. I studied astrophysics at the University of Maryland and met Joe Weber there. He got me hooked on gravitational detection, imaging and communication. His student, Robert Forward went on to help start the pathway to LIGO. So I spent much of my life trying to fulfill their vision. I helped the GravityResearchFoundation get online. I track all the low cost gravimeter technologies that can sample at "time of flight" or "that can take samples" on nanosecond time frames. I am learning to use all the online data stream from sensor on the earth because I cannot get anyone to simply try correlating the noise in their sensors on specific directions in the sky. And on specific locations inside the earth, its atmosphere and oceans and near space.
I don't expect anyone is interested in such things. So I will just leave this here, and go back to profiling the noise in these cameras across the full range of settings, temperature, vibration, seismic noise, magnetic field, electromagnetic field, and the varying gravitational field. Whatever I can find online. With the gravimeter and seismometer arrays, it is not uncommon to use a month of data for a tiny test. Or a decade for something harder. What's another ten or twenty years?
I put some things online at GravityNotes.Org and at https://hackaday.io/...avimeter-arrays
My assumption is the the gravitational potential field at the surface of the earth is in close relationship with the global magnetic potential, and that with the atmospheric thermal radiation field. They are tied together by the energy density. Robert Forward gave that as g^2/(9 pi G) and it is equivalent to a magnetic field of about 380 Tesla. I think it is number related, and there are just that many more gravitons than magnetic fluctuations, and then our photons are rather larger still and so fewer.
Richard Collins, Director, The Internet Foundation
I just joined Cloudy Nights. I am retired and never lived anywhere I could see the stars, or had time for it. Now I live in Houston Texas and it is raining again. Most days it is cloudy, and I live a couple of miles from downtown, the glare hurts my eyes.
With Covid I have my food delivered and buy everything from Amazon and online. So I thought, why not? I started to looked to see if I could rent time on an Internet telescope, somewhere the sky is clear. I did talk to some people wanting to host telescopes and put them online, but they charge more than my monthly, rent, food, utilities and bills combined. The local group I joined has a remote site, but not enough bandwidth. I am hoping to hear from them if anyone would record their sessions. I am kind of like a man dying of thirst. Any sky is better than no sky at all.
So I started finding all the live webcams in the world that show a bit of sky. It is very interesting. It is fascinating how many cameras are online, running 24 hours a day. No standards, often little purpose except a tiny bit of advertising. But, oddly, most sponsored and hopeful live webcams so not list the latitude, longitude and height of the camera, not its usual right ascension and declination, or altitude and azimuth. That aside, there are many hundreds, and I expect my list to grow to thousands. I don't sleep much, so lots of hours.
Many of these actually show the sky. AND I found many (less than a 100) "sky cams", "cloud cams", "meteorlogical cameras", "all sky cameras"
You know, I never learned the names of any constellations, and never really got a clear sense of where things are in the sky. I guess always busy, and no one had time to teach me. But in a few hours looking at some all sky camera images and time lapse videos of a clear sky, using Sky and Telescope and other models of where the stars, sun, moon, planets, and other things are out there. I began to get a sense that EVERY live or recorded camera on earth, with even a pixel of sky - day or night, there is a precise universe out there. I just cannot see it.
I asked my local group if they had considered putting a all sky camera on the internet somewhere so school kids, and older people like me, and lots of people who are working at home from Covid, might look at the sky, see the stars, artificial satellites, planes, and other things clearly marked and identifiable. I have dreams that I can just hover over anythings, and the computer can calculate the coordinates, look up what is there, and show to me.
I guess I better ask something? I am watching the histogram on a ZWO ASI120M camera as I have SharpCap step through all the exposures. I am using five second reads at 1 frame per seconds and stepping through all the exposures from 5 to 1000 milliseconds. On a camera sitting on my desk with the lens cap on. Just to see the noise. I have been a mathematical statistician all my life. I love noise. To me a sky full of stars is just a noisy signal with structure. I hope that is not too sacreligous? Anyway. I am running this poor camera through its paces. All the exposures, all the frame rates, all the gains, (I cannot do brightness, that seems to be broken in this IronPython/SharpCap/Windows Driver of some sort that I downloaded /some camera internal software that I cannot access or find anything about, to a sensor that has unique characteristics for each pixel in every operational setting, but no statistics anywhere.
I rather dislike Python. But I admire the IronPython group that got it to work in Windows, and the SharpCap people who at least can mostly talk to a whole bunch of camera. even if there is no statistical summary.
Oh I had bought a camera a year ago, but then spent months tracking the global status of Covid for my work. It is a SVbony something. When I looked at it (capped, why bother buy a telescope if you never see the sky?) it looked like I was seeing the sky. Hot bright pixels, sort of gray regions, splotches, some really dark areas. But in constant turmoil, some bright spots twinkling through the electron atmosphere at and in the electron wells of each pixel.
I bought two more ZWO cameras yesterday (my budget is not great, and I figure every single camera is going to be unique. Every pixel different, every pixel with noise that changes with every change in setting.) I know the rules and equations very well. But since it doesn't matter, I pretend I don't know and just watch the patterns and map the trends as I walk through the settings of each camera.
It just occurred to me that I can observer 24/7 with my "noise cameras", my "noise telescopes". I know where most of that noise comes from.
The reason I chose the ZWO cameras is because they can do "region of interest" at high frame rates. At frame rates above 299,000 frames per second, I only need to separate my sensors by a kilometer or more to see if I can track any signals that are not local. The spatial resolution for direction of arrival and time of flight is a kilometer. I have a LOT of pixels and lots of patience. If a cosmic ray electromagnetic pulse
I just need to increase the gain to spread the signal across more level of this (4096 level) sensor. And push the brightness as high as possible to put the "signal" into the middle. That doesn't work with ZWO and SharpCap, since since the thermal noise in the sensor is chopped off. I have been dreaming again that I could build my own camera from scratch. I would make several. Some with the tiniest electron (or hole) wells possible, then a stable amplifier, a stable reference voltage, and a fast and quiet and stable ADC - for each pixel.
No photon needed. The local photons inside - if you have patience, like I do, then after a month or a year of observing, the normal patterns are predictable. Yes, the Bayesian statistics are deep and complex, but they just represent the fairly limited existence of electrons in a fairly stable environment.
The data from the webcams is NOT real data. Without exception (I haven't found one yet) all the streams are lossy. Even the "observatories" pump out lossy jpeg and lossy video formats. You would think they would honor the pixels by preserving the original data, and not mushing it around for human viewers.
So I am still looking for someone with an all sky camera who shares their data stream of raw pixels. And someone who want to try chopping up the incoming stream of photons and energy with very high frame rates, so the direction of the signal can be determined by a global array of "noise cameras".
I thought that the big telescopes sites and the littler ones would have nice imaging arrays they do not use during the day. They could cover them nicely, and then monitor. But they are old big CCD pixels. But they might be able to take precise, globally coordinated, exposures of the noise to precisely scan the sky. Since there are lot of cameras out there, and radio and other sensors that track electron noise, they could take samples at precise moments to that signals coming from any point in the sky or inside the earth or sun or moon, could be correlated. Those radio telescope correlators might work. And there must be a lot of spare supercomputers lying around with nothing serious to do.
You know how hard it is to block a magnetic field. And the low frequency electric fields. Have you ever tried to stop gravity? It is extremely fine grained (spatial extent and low cross section). But if you watch the signals of a superconducting gravimeter, they precisely and faithfully track the sun and moon. The broadband seismometers are not as sensitive, but they gather a lot more data and are three axes. If only they could gather fast enough to resolve the direction of the tiny signals they see. They by simple correlation, it might be possible to scan the heavens in a different way.
I think I will be able to try to scan the heavens by correlating signals precisely at many thousands of location on the earth. A microsecond exposure and nanosecond time coordination seems possible. I do not know what is out there, but I feel it is a different sky than we imagined.