Successful comparisons between VHF oblique (15¿) radar echo profiles and reconstructed ones deduced from high-resolution temperature balloon measurements were presented by Luce et al. <1996>. The method was based on the evaluation of the three-dimensional isotropic refractive index spectrum at the Bragg wavelength from the available temperature profiles (spectral method). However, the isotropic hypothesis is questionable, especially in regions where temperature sheets <Dalaudier et al., 1994> are observed. Indeed, the associated anisotropic temperature fluctuations should contribute to the one-dimensional vertical temperature spectrum at small scales. In the present paper, another method, less sensitive to anisotropic contaminations, is used. This method is based on an estimation of the temperature structure constant CT2 from variances of horizontal differences of temperature measured by two high-resolution sensors 1 m apart horizontally (horizontal variance method). It is shown that the main differences between the CT2 estimations obtained from the two methods are mainly observed at high resolution in stable regions where few turbulent fluctations in the temperature field are observed. However, the two methods give approximately equivalent results at the radar range resolution (600 m) and the quality of the comparison with the radar observations is slightly improved with the horizatonal variance method. In order to demonstrate the full advantages of this technique, the use of radars with more powerful capabilities is suggested for future investigations.