325 research outputs found
Analysis of the September ε-Perseid outburst in 2013
We analyze the outburst experienced by the September ε-Perseid meteor shower on 9 September 2013. As a result of our monitoring the atmospheric trajectory of 60 multistation events observed over Spain was obtained and accurate orbital data were derived from them. On the basis of these orbits, we have tried to determine the likely parent body of this meteoroid stream by employing orbital dissimilarity criteria. In addition, the emission spectra produced by two events belonging to this meteor shower were also recorded. The analysis of these spectra has provided information about the chemical nature of their progenitor meteoroids. We also present an estimation of the tensile strength for these particles
Light pollution in Spain. An european perspective
Using DMPS satellite night images taken in 2000 we have estimated the saturated surface in many European countries. The objective of this study is to compare the illumination conditions and its effects in light pollution.
We have measured the surface of the saturated zone. We compare this parameter with the ratio of population density of the country. To avoid bias, normalize by dividing the area built in each country prior to the comparison. In this way only takes into account the surface that really makes sense to illuminate.
We have gathered the official data on energy consumption in public lighting in Spain. After plotting the evolution along the years we found changes in the way this value is obtained in different provinces of Spain and we made a more pessimistic prediction for the present energy consumption
Calibration of SQM-L photometers for the NixNox project
Twelve SQM-L night sky photometers have been tested and analyzed to determine their internal precision and differences in response. These photometers will be used by amateur astronomers around Spain, under the supervision of the Sociedad Española de AstronomĂa (SEA), to locate and characterize sites with dark skies well suited to perform astronomical observations (NixNox Project). A simple experimental setup has been built to obtain zero offsets for each photometer in order to correct all the observations
Orbits and emission spectra from the 2014 Camelopardalids
We have analysed the meteor activity associated with meteoroids of fresh dust trails of Comet 209P/LINEAR, which produced an outburst of the Camelopardalid meteor shower (IAU code #451, CAM) in 2014 May. With this aim, we have employed an array of high-sensitivity CCD video devices and spectrographs deployed at 10 meteor observing stations in Spain in the framework of the Spanish Meteor Network. Additional meteoroid flux data were obtained by means of two forward-scatter radio systems. The observed peak zenithal hourly rate was much lower than expected, of around 20 meteors h(-1). Despite of the small meteor flux in the optical range, we have obtained precise atmospheric trajectory, radiant and orbital information for 11 meteor and fireball events associated with this stream. The ablation behaviour and low tensile strength calculated for these particles reveal that Camelopardalid meteoroids are very fragile, mostly pristine aggregates with strength similar to that of the Orionids and the Leonids. The mineral grains seem to be glued together by a volatile phase. We also present and discuss two unique emission spectra produced by two Camelopardalid bright meteors. These suggest a non-chondritic nature for these particles, which exhibit Fe depletion in their composition
TESS Photometer Manual
The TESS-W photometer is a cheap and reliable photometer that it is used to measure night sky brightness. This document is the technical manual and calibration report
A Review of the Energy Potential of Residual Biomass for Coincineration in Kazakhstan
Although it has access to hydrocarbon reserves, Kazakhstan has developed a strategy for
the transition to a low-carbon economy, which should include the use of renewable energy sources.
In this framework, the use of biomass from waste could have the potential to reduce emissions from
traditionally fueled energy generation, as well as adding value to the generated waste, which also
improves waste management according to the principles of a circular economy. The analysis of the
resources and energy potential from residual biomass in Kazakhstan presents an annual production
of 37.26 106 tons of residual biomass, which could be capable of producing an energy potential
of 466.74 PJ/year, little more than half to the total production from all the installed power plants
in the country. Agricultural, animal and municipal solid waste are available to produce energy
in Kazakhstan based on combustion technologies; however, animal waste and agricultural are the
main potential sources with 61.02% and 38.34% of the theoretical total biomass potential energy
analyses, respectively. Considering that 80% of Kazakhstan’s electricity generation comes from
coal-fired plants, energy from agriculture could be co-fired for the gradual replacement of coal
with biomass in operational power plants, without substantially increasing costs or infrastructure
investments, thereby making the transition to a low-carbon economy and renewable energy sources
in the country easier.Government of the Republic of Kazakhstan
Ministry of Education and Science of the Republic of Kazakhstan AP14871168
AP14870834research group TEP-968 (Technologies for Circular Economy) of the University of Granad
Absolute Radiometric Calibration of TESS-W and SQM Night Sky Brightness Sensors
We develop a general optical model and describe the absolute radiometric calibration of the
readings provided by two widely-used night sky brightness sensors based on irradiance-to-frequency
conversion. The calibration involves the precise determination of the overall spectral sensitivity of the
devices and also the constant G relating the output frequency of the light-to-frequency converter chip
to the actual band-weighted and field-of-view averaged spectral radiance incident on the detector
(brightness). From these parameters, we show how to define a rigorous astronomical absolute
photometric system in which the sensor measurements can be reported in units of magnitudes per
square arcsecond with precise physical meaning.S
Magnitude to luminance conversions and visual brightness of the night sky
The visual brightness of the night sky is not a single-valued function of its brightness in other photometric bands, because the transformations between photometric systems depend on the spectral power distribution of the skyglow. We analyze the transformation between the night sky brightness in the Johnson-Cousins V band (mV, measured in magnitudes per square arcsecond, mpsas) and its visual luminance (L, in SI units cd m^(-2) ) for observers with photopic and scotopic adaptation, in terms of the spectral power distribution of the incident light. We calculate the zero-point luminances for a set of skyglow spectra recorded at different places in the world, including strongly light-polluted locations and sites with nearly pristine natural dark skies. The photopic skyglow luminance corresponding to m_(v)=0.00 mpsas is found to vary between 1.11-1.34 x 10^(5) cd m^(-2) if m_(v) is reported in the absolute (AB) magnitude scale, and between 1.18-1.43 x 10^(5) cd m^(-2) if a Vega scale for m_(v) is used instead. The photopic luminance for m_(v)=22.0 mpsas is correspondingly comprised between 176 and 213 µcd m^(-2) (AB), or 187 and 227 µcd m^(-2) (Vega). These constants tend to decrease for increasing correlated color temperatures (CCT). The photopic zero-point luminances are generally higher than the ones expected for blackbody radiation of comparable CCT. The scotopic-to-photopic luminance ratio (S/P) for our spectral dataset varies from 0.8 to 2.5. Under scotopic adaptation the dependence of the zero-point luminances with the CCT, and their values relative to blackbody radiation, are reversed with respect to photopic ones
- …