Detailed knowlege of the local atmospheric conditions is necessary for the correct interpretation of atmospheric radar observations. While the wind profile, and the associated vertical wind shear, can effectively be deduced from the Doppler radar measurements, the local static stability of the atmosphere can only be deduced from in situ observations. The present paper discusses some of the pitfalls and uncertainties associated with such estimations in relation with co-localization of the instruments. Nevertheless, the unique advantages of high resolution in situ measurements for the correct interpretation of remote sensing data are emphasized in the concluding section, even if the high resolution data itself is not shown or discussed here.

Large Eddy Simulations (LES) of the evolution of a stratified flow are presented for an horizontally towed grid in a linearly stratified flow, and indication of the well known stepwise effect are apparent and show a clear temporal variation.Detailed analysis of the unsteady turbulent stratified flow is given at the light of Phillips [17] and Posmentier [18] mechanism, in function of values of the Richardson number, and the influence of an initial internal wave is pointed out.

In the classical development of wind profiler systems, the VHF range (40-60 MHz) has been generally selected for high altitudes explorations (ST and MST systems) and the UHF range oriented mainly towards low altitudes soundings (T systems). Preliminary experiments in LSEET have shown that it was possible to investigate as low as 300 m with a low-power, small 50 MHz profiler radar in a classical configuration (squared, nxn). Bur using a small antenna array involves an increasing of the half-power beamwidth and of the overlapping in adjacent gates in oblique directions, and inverse methods have to be applied for atmospheric parameters retrieval. A new configuration of the antenna (two crossed lines) leads to decrease the oblique angle and the half-power beamwidth, and allows to reduce overlapping between adjacent gates. In this paper, measurements from the small profiler in these two different configurations (squared and crossed configurations) and from the Provence radar (reference radar) will be: compared, without using inverse methods. Validities of small radar measurements for horizontal velocities will be given in a quantitative way, as a function of the altitude and of the signal-to-noise ratio. Conclusions will be clearly exposed, and will indicate that measurements from the small profiler in crossed configuration ape not strongly affected by overlapping, and that then horizontal velocities can be interpreted directly without using inverse methods.

During eleven nights, two different instruments, a scintillation detection and ranging (SCIDAR) and a radar, were simultaneously operated to retrieve profiles of the atmospheric turbulence C2N(h). The SCIDAR spectral window lies between 5 cm and 25 cm, whereas the radar is sensitive to 3.3‐m wavelength. The profiles deduced from the SCIDAR and from the oblique (13°) radar agree fairly well, at least above 9 km, where the effects of specific humidity on radar returns are negligible. On eight occasions the agreement is good enough, over a large range of altitudes, to confirm the validity of Tatarski's theory of beam propagation, Kolmogorov's spectral laws, and Ottersten's description of radar returns.