Patent ID: 6473026
Filing Date: 2002-10-29
Classification: G01S,Y02A

Abstract:
A process for estimating a precipitation rate by means of a bipolar radar, comprising:differential phase &PHgr;dp and attenuated reflectivity Z according to at least one of polarizations H or V are measured by means of said bipolar radar, over a given interval [r1, r0] of path radius r with respect to said radar, wherein a reflectivity profile Z(r) is determined, an estimate of the attenuation value at r0K(r0) is determined from the attenuated reflectivity profile thus measured, as well as from a difference in differential phase between r0 and r1; an estimate of the specific attenuation at r K(r) as a function of the attenuation K(r0) thus determined and of the attenuated reflectivity profile Z(r) is determined, wherein the estimate K(r) of the specific attenuation is determined as a function of r from the equation Zb&it;(r)K&it;(r)-Zb&it;(r0)K&it;(r0)=I&it;(r,r0)â€ƒand wherein the estimate of the value K(r0) of the attenuation R0 is determined from the equation K&it;(r0)&it;&Integral;r1r0&it;Zb&it;(s)Zb&it;(r0)+K&it;(r0)&CenterDot;I&it;(s,r0)&it;&dd;s=Î³&CenterDot;(Ï†dp&it;(r0)-Ï†dp&it;(r1))â€ƒwhere: l(s,r0)=0.46bâˆ«rr0Zb(u)du, â€ƒb being the exponent of the power relation K(r)=a[Z0(r)]b (Z0:unattenuated reflectivity) â€ƒand where &ggr; is the parameter of proportionality between the specific attenuation and the differential rate of variation of the phase; the rate of precipitation R(r) is determined knowing K(r).