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Table 5 Parameters derived from the SA FCA

From: MF and HF radar techniques for investigating the dynamics and structure of the 50 to 110 km height region: a review

Symbol

Parameter

Description

V a

Apparent velocity

The velocity of the ground diffraction pattern over the spaced antennas calculated from the time delays of the cross-correlation function determined between pairs of antennas.

V t

True velocity

The velocity of the ground diffraction pattern over the spaced antennas calculated from the time delays of the cross-correlation function determined from pairs of antennas corrected for random changes in the pattern in time and for any pattern anisotropy. Additional quality control parameters are also applied to obtain this parameter (see Table 6).

w a

Apparent vertical velocity

Vertical velocity measured from the phase of the complex autocorrelation function measured on each antenna uncorrected for angle of arrival

w cor

Corrected vertical velocity

Vertical velocity corrected for effects of off-zenith mean angle of arrival

AOA

Mean angle of arrival

Mean angle of arrival

τ 0.5

Fading time

Mean auto-correlation function half-width

T 0.5

Pattern lifetime

Fading time in the frame of the ground diffraction pattern

S 0.5

Pattern scale

Major axis of the characteristic ellipse

R ax

Axial ratio

Ratio of the major to minor axes of the characteristic ellipse

\( \theta \) ax

Axial rotation

Direction of major axis of characteristic ellipse

PTD

Percentage time discrepancy

Ratio of sum of cross-correlation function maximum delay times to sum of absolute cross-correlation function delay times

SNR

Signal to noise ratio

The signal to noise ratios for each receiver channel

P

Received power

The received power for each receiver channel