0000000000496533
AUTHOR
Péter Takács
Lateral diffusion estimation in fully depleted thick CCD using flat field image analysis
Abstract In thick fully depleted CCDs charge carrier transport from the back window to the gates is accompanied by charge diffusion. Lateral diffusion smooths out density variations of the incoming photon flux by redistributing charges spatially. This creates short range positive correlations in recorded amplitudes. Pixel-to-pixel amplitude variations can also be caused by pixel size and quantum efficiency variations. Pixel size variations result in short range negative correlations. Our study shows that the characteristic diffusion width can be extracted from flat field data. The study was performed on fully depleted, thick CCDs produced in a technology study for the Large Synoptic Survey …
CCD characterization and measurements automation
Abstract Modern mosaic cameras have grown both in size and in number of sensors. The required volume of sensor testing and characterization has grown accordingly. For camera projects as large as the LSST, test automation becomes a necessity. A CCD testing and characterization laboratory was built and is in operation for the LSST project. Characterization of LSST study contract sensors has been performed. The characterization process and its automation are discussed, and results are presented. Our system automatically acquires images, populates a database with metadata information, and runs express analysis. This approach is illustrated on 55 Fe data analysis. 55 Fe data are used to measure …
Fish scale shape analyses: in mirror of phylogenetics
Several studies proved that fish scale shape is suitable for species identifcation, and for population level discrimination as well. There is lack of information about how the scale shape refer to the taxonomic position of a certain species. For this reason the scale shape of 10 fish species (roach Rutilus rutilus, chub Squalius cephalus, gibel carp Carassius gibelio, razorfish Pelecus cultratus, bleak Alburnus alburnus, carp Cyprinus carpio, topmouth gudgeon Pseudorasbora parva, perch Perca fluviatilis, pikeperch Sander lucioperca, rudd Scardinius erythrophthalmus), inhabiting the catchment of Lake Balaton was compared to their phylogenetic positions derived from COI sequences, available i…
Functional diversity of the Middle-Danubian fish fauna, the role of non-native species
It is well known that physical appearance and behavior of each species reflects to its habitat preference, feeding habits, etc. Therefore, one can describe the ecological role of species in a community by characterizing their life-history and functional traits. By applying this framework across all species present in the community, we can characterize its funcitonal diversity. The Middle-Danubian hydrosystem is characterised by valuable and diverse fish fauna, at the same time this area is highly exposed to the invasions because of the „natural" range expansion of Pontos-Caspic species and due to the illegal fish stockings. And although several notes deal with the effect of non-native speci…
The distribution patterns, risk and potential effect of non-indigenous fish species of Hungarian waters
Translocation and introduction of non-indigenous species might be considered as one of the least reversible human induced changes in nature. The background factors of a successful biological invasion are diverse; and the complete eradication of established invasive species seems practically impossible. The aim of our presentation is to (1) revise the trends and spreading mechanisms of non-indigenous species; (2) assess the potential ecological risk of new species in the catchment basin of a shallow lake (Lake Balaton, Hungary) and (3) to analyze the local and regional factors affecting the distribution patterns of gibel carp (Carassius gibelio), an effective invasive species of the region, …