Measurement of the21NeZeeman frequency shift due toRb−21Necollisions

Measurement of the 21 Ne Zeeman frequency shift due to Rb- 21 Ne collisions

Analytical and Experimental Comparisons Between the Frequency-Modulated-Frequency-Shift Measurement and the Pulsed-Wave-Time-Shift Measurement Doppler Systems

In previous publications, a new echo-ranging Doppler system based on transmission of repetitive coherent frequency-modulated ͑FM͒ sinusoids in two different implementations was presented. One of these implementations, the frequency-modulated–frequency-shift measurement ͑FM–fsm͒ Doppler system is, in this paper, compared with its pulsed-wave counterpart, the pulsed-wave– time-shift measurement ͑PW–ts...

Amplitude Shift Keying & Frequency Shift Keying

Aim: To generate and demodulate an amplitude shift keyed (ASK) signal and a binary FSK signal. Amplitude shift keying-ASK-in the context of digital communications is a modulation process, which imparts to a sinusoid two or more discrete amplitude levels. These are related to the number of levels adopted by the digital message. For a binary message sequence there are two levels, one of which is ...

Rotational Frequency Shift

The notion of the rotational frequency shift, an analog of the Doppler shift, is introduced. This new frequency shift occurs for atomic systems that lack rotational invariance, but have stationary states in a rotating frame. The rotational frequency shift is given by the scalar product of the angular velocity and the angular momentum of the emitted photon in full analogy with the standard Doppl...

Empirical Estimate of Frequency Shift

We have obtained empirical relations between the p-mode frequency shift and the change in solar activity indices. The empirical relations are determined on the basis of frequencies obtained from BBSO and GONG stations during solar cycle 22. These relations are applied to estimate the change in mean frequency for the cycle 21 and 23. A remarkable agreement between the calculated and observed fre...