Polarization radar techniques essentially rely on detecting the oblateness of raindrops to provide a measure of mean raindrop size and then using this information to give a better estimate of rainfall rate R than is available from radar reflectivity Z alone. To derive rainfall rates from these new parameters such as differential reflectivity ZDR and specific differential phase shift KDP and to ...

Techniques for the absolute calibration of radar reflectivity Z and differential reflectivity ZDR measured with dual-polarization weather radars are examined herein. Calibration of Z is based on the idea of self-consistency among Z, ZDR, and the specific differential phase KDP in rain. Extensive spatial and temporal averaging is used to derive the average values of ZDR and KDP for each 1 dB ste...

In this study, the quantitative precipitation estimation (QPE) capability of three X-band dual-polarization phased array radars (PAR) in Guangzhou, South China, was demonstrated, with an S-band operational radar as benchmark. Rainfall rate (R) estimators based on specific differential phase (KDP) for summer both and were derived from raindrop size distributions (DSDs) observed by a 2-dimensiona...

Abstract The properties of non-collinear phase-matching (PM) for potassium dihydrogen phosphate (KDP) crystal were calculated. calculated numerically type I phase matching and II-phase matching. group delay dispersion (GDD) was determined KDP at different slant angles types 0°, 40°, 60°, 900°. pumping, signal, idler wavelengths 354.7nm, 1064nm, 532nm respectively. time deepened on the angle thr...

The effect of the volumetric energy density (VED) on keyhole formation, microstructural evolution and associated mechanical properties AlSi10Mg fabricated by selective laser melting (SLM) has been systematically investigated. results indicated that three modes could be distinguished during process, corresponding to different VED ranges, i.e. conduction mode (<50 J mm-3), transitional (~50–65 (>...

In this paper, recent progress made in the development of quartz and KDP crystal based acousto-optic tunable filters (AOTF) are presented. These AOTFs are developed for operation over deep-UV to near-UV wavelengths of 190 nm to 400 nm. Preliminary output performance measurements of quartz AOTF and design specifications of KDP AOTF are presented. At 355 nm, the quartz AOTF device offered ~15% di...

KdpD and KdpE form a histidine kinase/response regulator system that senses K(+) limitation and induces the kdpFABC operon, which encodes a high-affinity K(+) uptake complex. To define the primary stimulus perceived by KdpD we focused in this study on the dynamics of the Kdp response. Escherichia coli cells were subjected to severe K(+) limitation, and all relevant parameters of the Kdp respons...

The Kdp system is widely distributed among bacteria. In Escherichia coli, the Kdp-ATPase is a high-affinity K+ uptake system and its expression is activated by the KdpDE two-component system in response to K+ limitation or salt stress. However, information about the role of this system in many bacteria still remains obscure. Here we demonstrate that KdpFABC in Staphylococcus aureus is not a maj...

The key factors, namely, the radar data quality, raindrop size distribution (RSD) variability, and integration method, which significantly affect radar-based quantitative precipitation estimation (QPE) are investigated using RCWF (S-band) NCU C-POL (C-band) dual-polarization radars in northern Taiwan. quality control (QC) procedures, including corrections of attenuation, systematic bias, wet-ra...