>Rockets generally tilt over at apogee, but I have seen many >slide directly backwards, making any sort of angle measurement an >uncertain indication of apogee. Sounds reasonable. I kind of suspected something like this.
>There's a lot of math involved in understanding why it works, but only a >very small amount of arithmetic to actually fly the rocket. Kalman >filters were developed for early space flight applications, including >Margaret Hamilton's firmware that landed spacecraft on the moon. Very interesting - I guess I'll have to find the time to dig deeper into this topic (and the code) :-) >GPS satellites are not in equatorial orbits and offer similar precision >over the entire planet Not equatorial but also not polar... Inclination of 55° means that at higher latitudes all the GPS satellites will be quite near to the horizon. This also means there are fewer satellites visible at one time. I agree that GPS might work if you are lucky and it might fail at more fortunate latitudes anyway. But in general it will be more difficult to get a GPS position the nearer to the poles you are. Actually our launch site for high altitude rockets, near Kiruna in north Sweden, is located at nearly 68° N, which is similar to Alaska or even north Antarctica (speaking of absolute values). Anyway, thank you very much, my questions are answered for the moment. By the way: Season's greetings to everyone! Andreas _______________________________________________ altusmetrum mailing list [email protected] http://lists.gag.com/mailman/listinfo/altusmetrum
