At highfrequencies, they allow fine resolutions and extremely precise image qualities to be obtained, from around ten centimeters to several tens of kilometers. At lower frequencies, they offer significant canopy or underground penetration capacity
From now on, its waves will travel towards our natural satellite, using a novel method: trans-ionospheric propagation, which consists in crossing the ionosphere, this time using the waves of highestfrequencies of the HF spectrum... We are mainly interested in the radar aspect: when a highfrequency wave crosses the ionospheric layers, it is slightly deflected
High quality continuous airflow at Mach number up to 0 38 or 0 18 respectively with 2m or 3m diameter convergent nozzle. Very good anechoicity and low background noise in the 200 Hz to 80 kHz frequency bandwidth... Airframe noise (High lift Devices noise, landing gear noise...)
The velocity gets higher toward the centre of the vortex... There is a frequency shift Df between the incident wave (fo) onto a particle in movement and the wave that it scatters (f1), as a function of its velocity of displacement... The DGV technique is used to determine this frequency shift Df. We can then obtain a component of the velocity
