Wyniki wyszukiwania - BazTech

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S-band and Ku-band SAR system development for UAV-based applications

Kaniewski Piotr, Komorniczak Wojciech, Leśnik Czesław, Cyrek Jacek, Susek Waldemar, Serafin Piotr, Łabowski Michał

Metrology and Measurement Systems

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2019

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Vol. 26, nr 1

53--64

EN

This paper describes a synthetic aperture radar system for tactical-level imagery intelligence installed on board an unmanned aerial vehicle. Selected results of its tests are provided. The system contains interchangeable S-band and Ku-band linear frequency-modulated, continuous wave radar sensors that were built within a frame of a research project named WATSAR, conducted by the Military University of Technology and WB Electronics S.A. One of several algorithms of radar image synthesis, implemented in the scope of the project, is described in this paper. The WATSAR system can create online and off-line radar images.

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The use of diatoms to assess the water quality in the Wisłoka River in the town of Dębica and the surrounding area

Noga T., Stanek-Tarkowska J., Peszek Ł., Pajączek A., Kochman-Kędziora N., Ligęzka R.

Oceanological and Hydrobiological Studies

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2016

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Vol. 45, No. 2

191--201

EN

The objective of this work was to examine the water quality using three diatom indices SPI, GDI and TDI. The material for the study was collected during four seasons from autumn 2010 to summer 2011, from four sampling sites located on the Wisłoka River, in the town of Dębica and the surrounding area. The Wisłoka at all selected sites was characterized by alkaline or close to neutral pH (pH 6.5-7.7). Electrolytic conductivity ranged from 364 to 480μS cm-1. The Wisłoka at the selected sites in the urban area and in the surrounding areas was characterized by high diatom species richness. The total of 238 taxa from 53 genera were recorded, of which the most numerous were: Nitzschia (44), Navicula (33) and Gomphonema (12). Achnanthidium minutissimum var. minutissimum, Amphora pediculus, Navicula gregaria, N. lanceolata, and Nitzschia dissipata ssp. dissipata were usually the dominant species. Chemical parameters indicated very good quality of water. However, the diatom indices used to assess the water quality, classified the studied water into a group corresponding to quality class III or IV.

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Modifications of Range-Doppler Algorithm for Compensation of SAR Platform Motion Instabilities

Gorovyi I. M., Bezvesilniy O. O., Vavriv D. M.

International Journal of Electronics and Telecommunications

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2014

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Vol. 60, No. 3

225-231

EN

Two modifications of the range-Doppler algorithm (RDA) have been proposed to solve problems of SAR platform motion instabilities. First, the multi-look processing based on the RDA with an extended Doppler bandwidth has been introduced for correction of radiometric errors. Second, the RDA has been modified to perform SAR image formation on short-time acquisition intervals to use it in a recently-developed local-quadratic map-drift autofocus (LQMDA) method. The performance of the methods is illustrated with experimental data obtained by airborne SAR systems.

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Scaling relationships of leaf traits do not change among months in a temperate shrub species

Du N., Wang R.-Q., Zhang X.-R, Xu F., Tan X.-F., Guo W.-H.

Polish Journal of Ecology

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2013

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Vol. 61, nr 1

23--34

EN

Leaf traits scaling relationships were compared in different months (May, June, July and August) in a temperate shrub species, Vitex negundo Linn. var. heterophylla (Franch.) Rehd. Leaf traits variation and the impact of environment were also studied. Our results showed that specific leaf area (SLA), leaf nitrogen content (Nmass), leaf phosphorus content (Pmass) and leaf chlorophyll content (Chlmass) were positively correlated, and all of the pairwise relationships showed a common standardized major axis (SMA) slope in different months. The variation of SLA, chlorophyll a content (Chlmass a), chlorophyll b content (Chlmass b), Chlmass a/b and maximum quantum yield of PSII (Fv/Fm) were mainly habitat-dependent, while the variation of Pmass and Nmass/Pmass were mainly month-dependent. Redundancy analysis (RDA) was used to further explore the relationships between leaf traits and environmental factors. We found that plants under shade (the relative photosynthetic photon flux density was about 10%) developed light-capturing behavior at leaf level (higher SLA) and cellular level (higher Chlmass/Nmass and lower Chlmass a/b). The increased Nmass/Pmass with month was mainly resulted from the large absorption of soil nitrogen and the decrease of soil pH. In a word, our study indicates that species may not have fundamentally different carbon capture strategies in different months. Variation of different leaf traits are related to different environmental factors in the field.