A new approach to MF radar interferometry for estimating mean winds and momentum flux

Abstract

Abstract. New techniques are applied to measured Doppler velocity and angle of arrival to estimate horizontal wind vectors, variances, and momentum fluxes, from MF radar data. The approach used to estimate mean winds was first introduced as "time domain interferometry" (TDI) by Vandepeer and Reid [1995]. In the present paper, the algorithm is refined and used with data from the Urbana MF radar, which employs a single vertical antenna beam, to obtain a monthly mean wind climatology which is compared with the results from conventional spaced antenna full correlation analysis. The comparison validates the scattering model used in the development of the TDI technique and highlights instrumental and processing biases that differ between the two techniques. An extension of the TDI method that can provide estimates of the Reynolds stress tensor associated with propagating gravity waves is also proposed, and some preliminary results are presented.

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

“…While noisier, the gray profile looks similar in form. Note that this last analysis is a version of that suggested by Thorsen et al (1997) and for this case, with a relatively narrow transmitter beam (~20°for these observations), appears to deliver a tolerable result for this difficult to measure Fig. 18 Shows a typical example of the effective receiver beam positions for the BPMF radar operating in an east (red), west (yellow), north (green), south (blue), and vertical (pink) transmitter beam sequence.…”

“…Thorsen et al (1997) provided a more extensive theoretical formulation for the TDI approach and considered ordinary and total least squares fitting to TDI radial velocities to derive the mean and fluctuating components of the wind field. In so doing, they extended TDI to measurements of the three-dimensional mean winds and of the Reynolds stress tensor for small MF/HF PR SA radars.…”

“…The results indicated by the gray line are calculated in the same way as the black line but using only the vertically directed beam. These then correspond to the Thorsen et al (1997) approach described in the text (after Spargo et al 2015). For further details, see the text for FCA, FSA, SCA, IDI, HDI, TDI, or Doppler beam steering, but the analysis applied differs.…”

On the optimum radar beam angle to minimize statistical estimation error of momentum flux using conjugate beam technique

“…But it is only recently that attention has been paid to estimate the errors associated with the method. The effect of geophysical noise in the measurement of momentum and heat flux has been addressed by several workers [Tao and Gardner, 1995;Thorsen et al, 1997;Gardner and Yang, 1998;Riggin et al, 2004;Dutta et al, 2005]. Kudeki and Franke [1998] showed that the dominant contribution to the uncertainty of momentum flux estimates scales as the geometric mean of the horizontal and vertical wind fluctuation variances and to obtain statistically significant measurements of momentum flux, long integration times are necessary.…”

Mesospheric gravity wave momentum flux estimation using hybrid Doppler interferometry

“…The received beams were analysed with hybrid Doppler interferometry (HDI) (Holdsworth and Reid, 1998), principally to determine the radial velocities of the effective scattering centres illuminated by the radar. The methodology of Thorsen et al (1997), later re-introduced by Hocking (2005) and since extensively applied to meteor radar returns, was used to estimate components of Reynolds stress due to propagating GWs and/or turbulence in the radar resolution volume. Physically reasonable momentum flux estimates are derived from the Reynolds stress components, which are also verified using a simple radar model incorporating GW-induced wind perturbations.…”