Fabregas, F.; campeny, A.; Casorran, M.; Rodríguez, J.; Martinez, F. Congrés de l'Associació de Professionals dels Espais Verds de Catalunya p. 47-62 Data de presentació: 2015-03-20 Presentació treball a congrés
L’objectiu de l’assaig es estudiar el comportament de 48 exemplars, de Platanus X acerifolia en 4
tipus de terra (terra del lloc, terra tipus Amsterdam, terra vegetal i terra del lloc esmenada) i 3 tipus de millores aplicades a la terra de plantació (grava basal, tensioactiu i hidrogel)
Gil, E.; Balsari, Paolo; Gallart, M.; Llorens, J.; Marucco, Paolo; Andersen, Per Gummer; Fabregas, F.; Llop, J. Crop protection Vol. 56, p. 58-68 DOI: 10.1016/j.cropro.2013.10.018 Data de publicació: 2014-02 Article en revista
This study's objective was to evaluate the functionality of an ad hoc test bench for spray drift measurement with boom sprayers, using it for evaluating different nozzles according to drift risk. The repeatability of results was evaluated by conducting similar tests at two different laboratories. Drift potential values (DPV) obtained showed an interesting effect of Venturi flat fan nozzles on drift reduction, in comparison with conventional flat fan nozzles (reference nozzle was XR 11003). Newly designed flat fan nozzles reduced the risk of drift. Reasonably relations between 10th-percentile, D[v,0.1], 50th-percentile or Volume Median Diameter, D[v,0.5], 90th-percentile, D[v,0.9], V100 and DPV were observed in all cases, with R2 values of 0.58, 0.65, 0.66 and 0.72, respectively. The lowest drift values were achieved with TTI and TD Spray Max nozzles; they were significantly lower than those obtained for IDK and AIXR ones. Results indicated that the drift test bench can be used as an alternative to the official standard procedure for drift measurements on boom sprayers (e.g. ISO 22866), as it is able to discriminate the influence of different boom settings (especially nozzle types) on drift. Further studies could be useful in order to prove that the classification of nozzles according to drift risk obtained using the test bench is comparable to the nozzle classifications obtained applying the ISO 22866 test method.
Gil, E.; Llorens, J.; Llop, J.; Fabregas, F.; Escolà, A.; Rosell, J.R. Computers and electronics in agriculture Vol. 95, p. 136-150 DOI: 10.1016/j.compag.2013.02.010 Data de publicació: 2013-07 Article en revista
The structural characteristics of the canopy are a key consideration for improving the efficiency of the spray application process for tree crops. However, obtaining accurate data in an easy, practical, and efficient way is an important problem to be solved. This paper describes the technical characteristics of a sprayer prototype developed for vineyards, following the principles and previous laboratory tests described in the complementary paper Variable rate sprayer. Part 1 – Orchard prototype: design, implementation and validation. This prototype can modify the sprayed volume application rate according to the target geometry by using an algorithm based on the canopy volume inspired by the tree row volume (TRV) model.
The use of a scanning Light Detection and Ranging (LIDAR) system to
characterize drift during pesticide application is described. The LIDAR system is compared
with an ad hoc test bench used to quantify the amount of spray liquid moving beyond the
canopy. Two sprayers were used during the field test; a conventional mist blower at two air
flow rates (27,507 and 34,959 m3·h-1) equipped with two different nozzle types
(conventional and air injection) and a multi row sprayer with individually oriented air
outlets. A simple model based on a linear function was used to predict spray deposit using
LIDAR measurements and to compare with the deposits measured over the test bench.
Results showed differences in the effectiveness of the LIDAR sensor depending on the
sprayed droplet size (nozzle type) and air intensity. For conventional mist blower and low
air flow rate; the sensor detects a greater number of drift drops obtaining a better
correlation (r = 0.91; p < 0.01) than for the case of coarse droplets or high air flow rate. In
the case of the multi row sprayer; drift deposition in the test bench was very poor. In
general; the use of the LIDAR sensor presents an interesting and easy technique to
establish the potential drift of a specific spray situation as an adequate alternative for the
evaluation of drift potential.
Margarit, G.; Mallorqui, J.J.; Fabregas, F. IEEE transactions on geoscience and remote sensing Vol. 11, num. 45, p. 3494-3502 DOI: 10.1109/TGRS.2007.897437 Data de publicació: 2007-10 Article en revista
This paper presents a novel method for vessel classification based on single-pass polarimetric synthetic aperture radar (SAR) interferometry. It has been developed according to recent ship scattering studies that show that the polarimetric response of many types of vessels can be described by trihedral- and dihedral-like mechanisms. The adopted methodology is quite simple. The input interferometric data are decomposed in terms of the Pauli basis, and hence, one height image is derived for each simple mechanism. Then, the local maxima of these images are isolated, and a 3-D map of scatters is generated. The correlation of this map with the scattering distribution expected for a set of reference ships provides the final classification decision. The performance of the proposed method has been tested with the orbital SAR simulator developed at Universitat PolitÈcnica de Catalunya. Different vessel models have been processed with a sensor configuration similar to the incoming TanDEM-X system. The analysis of diverse vessel bearings, vessel speeds, and sea states shows that the map of scatters matches reasonably the geometry of ships allowing a correct identification even for adverse environmental conditions.
Bech, J.; Vilaclara, E.; Pineda, N.; Rigo, T.; López, J.; O'Hora, F.; Lorente, J.; Sempere-Torres, D.; Fabregas, F. European Conference on Radar in Meteorology and Hydrology p. 416-420 Presentació treball a congrés
Bech, J.; Vilaclara, E.; Pineda, N.; Rigo, T.; López, J.; O'Hora, F.; Lorente, J.; Sempere-Torres, D.; Fabregas, F. European Conference on Radar in Meteorology and Hydrology p. 64 Presentació treball a congrés