Me armastame Wazet

[yeekim]

"So a time period, say one second is measured off and the coordinates are computed before and after the interval. The difference in location is computed as distance travelled in the second and thus with distance and elapsed time the a velocity and direction can be computed easily."

Nojah, see inimene keda sa tsiteerid ei tea ka asja. Siin on vähe põhjalikum selgitus: http://www.aprs.net/vm/gps_cs.htm

Teab ikka ja mina ka, aga igapäevase kasutajana, tuleb paraku tunnistada, et aeg on edasi läinud:
"In early GPS receivers, four PRs from 4 satellites was converted into a 3-D (XYZ, Lat/Lon/Hgt or whatever) position plus the calibration of the timing bias of your receiver, and 4 PRRs were converted into a 3-D velocity plus a measurement of the frequency error of the oscillator. More modern receivers take all the PR+PRR data from all the N satellites in view for the past T seconds and feeds the 2NT PR+PRR samples it into a single mathematical "black box" (BB) (usually a Kalman filter) to produce an over- determined estimate of the same 8 parameters. So in modern receivers, this BB is using both the combination of past & present PRs and PRRs from many satellites to improve the Position, Velocity & Time (PVT) estimate. So Paul's statement about velocities being determined by changes in position is sorta, partially correct, but (when you look at the equations inside the BB), the measured "apparent Doppler" frequencies are even more important. "

TNX