101–110 of 112 posts
I am probably missing something huge. But if the goal is a stable image why use gyros. use the image itself to apply the correction factor to the final integration. sort of the same way videos are stabilized.
This is analogous to astro-photography problems with keeping stars as points rather than as blurred lines in long exposures. If you think about it, if a long exposure at night has a static landscape but moving stars, the IBIS equivalent would have static stars and a moving landscape :)
https://youtu.be/DmwaUBY53YQ
https://youtu.be/zRTJ5ISmVXEEarlier quoted context omitted.
The IMUs that existed on aircraft before the invention of GPS have been superseded by the ones which actually are in your phone, in much the same way and for much the same reason that a $20 Casio F-91w keeps better time than a fancy Rolex that costs more than a house in California: electronics are cheaper and better than mechanical systems. We have, naturally, also made better IMUs for places where it matters, ones w…
Actually that F91W does not keep very good time. There pretty excellent if you keep them on a shelf bit if you run around outside in the hot and cold (you know, like people use a watch) they'll deviate quickly. Because they don't have a temperature controlled (or even compensated) oscillator. A real TXCO (basically putting the crystal inside a temp calibrated oven) is not feasible on a watch battery but compensation…
Nitpick: You're thinking about OCXO for crystals inside an oven, TCXOs are temperature compensated crystal oscillators
You don't need GPS to figure out the correction for this. Inertial navigation systems in aircraft (which use very stabilised platforms with a lot of math involved) worked before GPS was available. It helps to have a rough indication of the current latitude on startup, but you can also figure it out from the gyro outputs. Just takes longer. With modern sensors (solid state laser gyroscopes) it has all become a lot sma…
> You don't need GPS to figure out the correction for this. Perhaps not, but a lot of cameras already have it for geotagging purposes (EXIF), so why not use it: * https://en.wikipedia.org/wiki/List_of_cameras_which_provide_... * https://www.digitalcameraworld.com/buying-guides/best-camera...
Simply using the accelerometers and gyro directly does give the info you want. GPS is useless.
Why not stabilize optically? I am probably missing something huge. But if the goal is a stable image why use gyros. use the image itself to apply the correction factor to the final integration. sort of the same way videos are stabilized.
Photo hobbyists are snobs :)
Why not stabilize optically? I am probably missing something huge. But if the goal is a stable image why use gyros. use the image itself to apply the correction factor to the final integration. sort of the same way videos are stabilized.
The second way is undesirable because it's really hard. There is a lot of research into this and some of the results are good but some are not.
Earlier quoted context omitted.
There was an escape system in the Soyuz rocket that fired if the rocket tilted too much. It was based on gyroscopes. Once, a launch was aborted just before liftoff. The rocket stayed on the pad and the cosmonauts were sitting in the spacecraft for some time. Suddenly the abort system fired and pulled the capsule from the rocket. They landed safely on parachutes. It was discovered that earth had rotated and the gyrosc…
I think you’re mixing up different launches: Soyuz 7K-OK No.1 and Soyuz 7K-ST No.16L Soyuz 7K-OK No.1 was uncrewed and likely had the quirk with the gyros. One person near the launch on the ground was killed. https://en.wikipedia.org/wiki/Soyuz_7K-OK_No.1 > Initially, it was suspected that the booster had been bumped when the gantry tower was put back in place following the abort and that this somehow managed to trig…
Earlier quoted context omitted.
I think you’re mixing up different launches: Soyuz 7K-OK No.1 and Soyuz 7K-ST No.16L Soyuz 7K-OK No.1 was uncrewed and likely had the quirk with the gyros. One person near the launch on the ground was killed. https://en.wikipedia.org/wiki/Soyuz_7K-OK_No.1 > Initially, it was suspected that the booster had been bumped when the gantry tower was put back in place following the abort and that this somehow managed to trig…
Thanks! This happens so often when going from memory...
Earlier quoted context omitted.
Actually that F91W does not keep very good time. There pretty excellent if you keep them on a shelf bit if you run around outside in the hot and cold (you know, like people use a watch) they'll deviate quickly. Because they don't have a temperature controlled (or even compensated) oscillator. A real TXCO (basically putting the crystal inside a temp calibrated oven) is not feasible on a watch battery but compensation…
I picked it not because it's good, but to illustrate the cheapest digital is still better than any analog mechanism that money can buy.