References in periodicals archive ?
Caption: 3D VELOCITY Although measuring the Doppler shift of spectral lines provides astronomers with an object's radial velocity, it's really just a lower limit: Observers don't know its total 3D velocity until they also measure its proper motion and distance.
The performance is decline because Delay Spread: Frequency Selective Fading causing the Inter-Symbol Interference (ISI) and the signal power to be weakened and because Doppler Shift causing the frequency signal wave to be changed or distorted.
If an OFDM block is affected by Doppler fluctuation, using Doppler shift average is insufficient for finding an appropriate resampling ratio.
where N and [N.sub.D] are the length of one OFDM symbol and the discrete length of Doppler shift, respectively.
This is consistent with the RA and Dec for December from the NASA Doppler shift data [5].
The value of Doppler shift of path A-C-B, path A-C-D and path E-F are all minus because the receiver runs away from the transmitter.
Upon receiving the Sync-Req message, the reference node estimates and records the ordinary node's relative moving velocity [v.sub.0] with Doppler shifts. Meanwhile, it marks its local time as [t.sub.2].
However, the approach can only work well when the normalized maximum Doppler shift, defined as the maximum Doppler shift normalized to the subcarrier spacing, is less than 0.2.
where [f.sub.D] is the maximum Doppler shift introduced by the channel which is linearly related to the speed of either the transmitter or the receiver.
Assuming that the transmitter is fixed and the speed of receiver is 1m/s, the Doppler shift will vary between -800 Hz and 800 Hz.
Given the random time-varying characteristic of the ionospheric medium, the multi-path time delay and Doppler shift effects are the main features for the HF radar wave propagating through the ionosphere [2].