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AssigneeVaisala Oy
InventorsPentti Karhunen, Henry Andersson
Estimating the term…
Method and apparatus for measurement of the velocity of a moving target (20) in radio frequencies. From the measurement station (10) and from the target station (20), radio signals (S.sub.1,S.sub.2) are transmitted that are in different frequency ranges, as compared with each other, so that the receivers at the measurement station (10) and at the target station (20) are not subjected to interference. The radio signals (S.sub.1,S.sub.2) are received at stations (20,10) opposite to their transmission stations (10,20). The oscillator of the target station (20) is locked with the frequency transmitted by the measurement station (10) by means of a phase-locked loop (PLL). The frequency of said oscillator is passed to the transmitter part of the target station (20). The signal (S.sub.2) transmitted by the target station (20) is received at the measurement station (10). The Doppler shift (fd) of the frequency of the signal (S.sub.1) transmitted from the measurement station (10) and of the signal received at the measurement station is measured, and the velocity (v) of the moving target to be measured is determined on the basis of the Doppler shift.
Method for measurement of the velocity of a moving target (20) by making use of electromagnetic radiation, which is preferably in the range of radio frequency, and in which method a radio transmitter-receiver arrangement is employed both at the measurement station (10) and at the target (20) to be measured, by means of which arrangement radio signals are transmitted to and received from the opposite station (10), and in which method the Doppler shift (fd) included in the frequency of the signal (S.sub.1, S.sub.2) transmitted from and received at the measurement station (10) is detected at the measurement station (10), and on the basis of the Doppler shift (fd) the velocity (v) of escape and/or approach of the target (20) to be measured in relation to the measurement station (10) is determined, characterized in that the medium comprises a combination of the following steps:
Apparatus intended for measurement of the velocity of a moving target (20) by making use of electromagnetic radiation, which is preferably in the range of radio frequency, and in which a radio transmitter-receiver arrangement is employed both at the measurement station (10) and at the target (20) to be measured, by means of which arrangement radio signals are transmitted to and received from the opposite station (10), and wherein the Doppler shift (fd) included in the frequency of the signal (S.sub.1, S.sub.2) transmitted from and received at the measurement station (10) is detected at the measurement station (10), and on the basis of the Doppler shift (fd) the velocity (v) of escape and/or approach of the target (20) to be measured in relation to the measurement station (10) is determined, the apparatus comprising a transmitter-receiver arrangement and an antenna placed at the measurement station (10) and a corresponding transmitter-receiver arrangement and an antenna placed at the moving target (20) to be measured, characterized in that:
Dependencies are inferred from the claim text.