ALBERT

Description: We demonstrate compact, low power, lightweight laser-based sensors for measuring trace gas species in the atmosphere designed specifically for electronic unmanned aerial vehicle (UAV) platforms. The sensors utilize non-intrusive optical sensing techniques to measure atmospheric greenhouse gas concentrations with unprecedented vertical and horizontal resolution (~1 m) within the planetary boundary layer. The sensors are developed to measure greenhouse gas species including carbon dioxide, water vapor and methane in the atmosphere. Key innovations are the coupling of very low power vertical cavity surface emitting lasers (VCSELs) to low power drive electronics and sensitive multi-harmonic wavelength modulation spectroscopic techniques. The overall mass of each sensor is between 1–2 kg including batteries and each one consumes less than 2 W of electrical power. In the initial field testing, the sensors flew successfully onboard a T-Rex Align 700E robotic helicopter and showed a precision of 1% or less for all three trace gas species. The sensors are battery operated and capable of fully automated operation for long periods of time in diverse sensing environments. Laser-based trace gas sensors for UAVs allow for high spatial mapping of local greenhouse gas concentrations in the atmospheric boundary layer where land/atmosphere fluxes occur. The high-precision sensors, coupled to the ease-of-deployment and cost effectiveness of UAVs, provide unprecedented measurement capabilities that are not possible with existing satellite-based and suborbital aircraft platforms.

Description: A measurement program designed to evaluate health impacts or benefits of using ethanol blend petrol examined exhaust and evaporative emissions from 21 vehicles representative of the current Australian light duty petrol (gasoline) vehicle fleet using a composite urban emissions drive cycle. The fuels used were unleaded petrol (ULP), ULP blended with either 5% ethanol (E5) or 10% ethanol (E10). The resulting data were combined with inventory data for Sydney to determine the expected fleet emissions for different uptakes of ethanol blended fuel. Fleet ethanol compatibility was estimated to be 60% for 2006, and for the air quality modelling it was assumed that in 2011 over 95% of the fleet would be ethanol compatible. Secondary organic aerosol (SOA) formation from ULP, E5 and E10 emissions was studied under controlled conditions by the use of a smog chamber. This was combined with meteorological data from Sydney for February 2004 and the emission data (both measured and inventory data) to model pollutant concentrations in Sydney’s airshed for 2006 and 2011. These concentrations were combined with the population distribution to evaluate population exposure to the pollutant. There is a health benefit to the Sydney population arising from a move from ULP to ethanol blends in spark-ignition vehicles. Potential health cost savings for Urban Australia (Sydney, Melbourne, Brisbane and Perth) are estimated to be A$39 million (in 2007 dollars) for a 50% uptake (by ethanol compatible vehicles) of E10 in 2006 and $42 million per annum for a 100% take up of E10 in 2011. Over 97% of the estimated health savings are due to reduced emissions of PM2.5 and consequent reduced impacts on mortality and morbidity (e.g., asthma, cardiovascular disease). Despite more petrol-driven vehicles predicted for 2011, the quantified health impact differential between ULP and ethanol fuelled vehicles drops from 2006 to 2011. This is because modern petrol vehicles, with lower emissions than their older counterparts, will make up a higher proportion of the fleet in the future. Hence the beneficial effects of reductions in particulate matter become less significant as the fleet as a whole produces lower emissions.

Description: La Salle and Ebro Observatory have been involved in remote sensing projects in Antarctica for the last 11 years (approximately one solar cycle). The Ebro Observatory has been monitoring and analyzing the geomagnetic and the ionospheric activity in the Antarctic Spanish station Juan Carlos I (ASJI) (62.7°S, 299.6°E) for more than eighteen and ten years, respectively. La Salle has two main goals in the project. The first one is the data transmission and reception from Antarctica to Spain to obtain a historical series of measurements of channel sounding of this 12,760-km ionospheric HF (high frequency) radio link. The second one is the establishment of a stable data low power communication system between the ASJI and Cambrils, Spain (41.0°N, 1.0°E), to transmit the data from the remote sensors located on the island. In this paper, both narrowband and wideband soundings have been carried out to figure out the channel availability performed using a frequency range from 2 to 30 MHz with 0.5 MHz step during the 24 h of the day, encompassing wider channel measurements than previously done, in terms of hours and frequency. This paper presents the results obtained for the austral summer in 2014, using a monopole antenna at the transmitter and an inverted V on the receiver side. These results led us to the final physical layer design for the long Remote Sens. 2015, 7 11713 haul link, dividing the day into two parts: daytime, with low data throughput design, and nighttime, reaching high data throughput.

Description: In recent decades, the performance of economic and non-economic activities has required them to be friendly with the environment. Transport is one of the areas having considerable potential within the scope. The main assumption to achieve ambitious green goals is an effective green transport evaluation system. However, these systems are researched from the industrial company and supply chain perspective only sporadically. The aim of the paper is to design a conceptual framework for creating the Green Transport (GT) Balanced Scorecard (BSC) models from the viewpoint of industrial companies and supply chains using an appropriate multi-criteria decision making method. The models should allow green transport performance evaluation and support of an effective implementation of green transport strategies. Since performance measures used in Balanced Scorecard models are interdependent, the Analytic Network Process (ANP) was used as the appropriate multi-criteria decision making method. The verification of the designed conceptual framework was performed on a real supply chain of the European automotive industry.

Description: Wetlands worldwide are becoming increasingly degraded, and this has motivated many attempts to manage and restore wetland ecosystems. Restoration actions require a large resource investment, so it is critical to measure the outcomes of these management actions. We evaluated the restoration of floodplain wetland vegetation across a chronosequence of land uses, using remote sensing analyses. We compared the Landsat-based fractional cover of restoration areas with river red gum and lignum reference communities, which functioned as a fixed target for restoration, over three time periods: (i) before agricultural land use (1987–1997); (ii) during the peak of agricultural development (2004–2007); and (iii) post-restoration of flooding (2010–2015). We also developed LiDAR-derived canopy height models (CHMs) for comparison over the second and third time periods. Inundation was crucial for restoration, with many fields showing little sign of similarity to target vegetation until after inundation, even if agricultural land uses had ceased. Fields cleared or cultivated for only one year had greater restoration success compared to areas cultivated for three or more years. Canopy height increased most in the fields that were cleared and cultivated for a short duration, in contrast to those cultivated for >12 years, which showed few signs of recovery. Restoration was most successful in fields with a short development duration after the intervention, but resulting dense monotypic stands of river cooba require future monitoring and possibly intervention to prevent sustained dominance. Fields with intensive land use histories may need to be managed as alternative, drier flood-dependent vegetation communities, such as black box (Eucalyptus largiflorens) grasslands. Remotely-sensed data provided a powerful measurement technique for tracking restoration success over a large floodplain.

Description: The trend in the last few decades is that current unmanned aerial vehicles are completely made of composite materials rather than metallic, such as carbon-fiber or fiberglass composites. From the electromagnetic point of view, this fact forces engineers and scientists to assess how these materials may affect their radar response or their electronics in terms of electromagnetic compatibility. In order to evaluate this, electromagnetic characterization of different composite materials has become a need. Several techniques exist to perform this characterization, all of them based on the utilization of different sensors for measuring different parameters. In this paper, an implementation of the metal-backed free-space technique, based on the employment of antenna probes, is utilized for the characterization of composite materials that belong to an actual drone. Their extracted properties are compared with those given by a commercial solution, an open-ended coaxial probe (OECP). The discrepancies found between both techniques along with a further evaluation of the methodologies, including measurements with a split-cavity resonator, conclude that the implemented free-space technique provides more reliable results for this kind of composites than the OECP technique.

Description: This study illustrates the inherent complexity and uncertainties surrounding the Guatemalan potato moth pest on Tenerife that has affected potato crops for several decades using a Socio-Institutional methodology and a farmers’ focus group. It focuses on detecting major socioeconomic and environmental impacts caused by the pest. It identifies the stakeholders and historical decisions involved as well as systemic uncertainties. This methodology generates socially robust knowledge and introduces new variables into future decision-making processes. The results show that the efforts made so far to control the pest, based on technical and scientific knowledge, have not been commensurate with the enormous complexity of the issue. Novel alternatives to eliminate the plague and new recommendations have emerged after the application of the methodology. These alternatives and recommendations are related to breaking the reproduction cycle of the moth; promoting agro-ecological strategies and participatory processes; and dealing with uncertainties such as climate change or loss of agro-biodiversity on the island.

Description: Urbanization continues to be a transformative process globally, affecting ecosystem integrity and the health and well being of people around the world. Although cities tend to be centers for both the production and consumption of goods and services that degrade natural environments, there is also evidence that urban ecosystems can play a positive role in sustainability efforts. Despite the fact that most of the urbanization is now occurring in the developing countries of the Global South, much of what we know about urban ecosystems has been developed from studying cities in the United States and across Europe. We propose a conceptual framework to broaden the development of urban ecological research and its application to sustainability. Our framework describes four key contemporary urban features that should be accounted for in any attempt to build a unified theory of cities that contributes to urban sustainability efforts. We evaluated a range of examples from cities around the world, highlighting how urban areas are complex, connected, diffuse and diverse and what these interconnected features mean for the study of urban ecosystems and sustainability.

Description: The concentration, type, and extent of sea ice in the Arctic can be estimated based on measurements from satellite active microwave sensors, passive microwave sensors, or both. Here, data from the Advanced Scatterometer (ASCAT) and the Special Sensor Microwave Imager/Sounder (SSMIS) are employed to broadly classify Arctic sea ice type as first-year (FY) or multiyear (MY). Combining data from both active and passive sensors can improve the performance of MY and FY ice classification. The classification method uses C-band σ0 measurements from ASCAT and 37 GHz brightness temperature measurements from SSMIS to derive a probabilistic model based on a multivariate Gaussian distribution. Using a Gaussian model, a Bayesian estimator selects between FY and MY ice to classify pixels in images of Arctic sea ice. The ASCAT/SSMIS classification results are compared with classifications using the Oceansat-2 scatterometer (OSCAT), the Equal-Area Scalable Earth Grid (EASE-Grid) Sea Ice Age dataset available from the National Snow and Ice Data Center (NSIDC), and the Canadian Ice Service (CIS) charts, also available from the NSIDC. The MY ice extent of the ASCAT/SSMIS classifications demonstrates an average difference of 282 thousand km - + from that of the OSCAT classifications from 2009 to 2014. The difference is an average of 13.6% of the OSCAT MY ice extent, which averaged 2.19 million km2 over the same period. Compared to the ice classified as two years or older in the EASE-Grid Sea Ice Age dataset (EASE-2+) from 2009 to 2012, the average difference is 617 thousand km2 . The difference is an average of 22.8% of the EASE-2+ MY ice extent, which averaged 2.79 million km2 from 2009 to 2012. Comparison with the Canadian Ice Service (CIS) charts shows that most ASCAT/SSMIS classifications of MY ice correspond to a MY ice concentration of approximately 50% or greater in the CIS charts. The addition of the passive SSMIS data appears to improve classifications by mitigating misclassifications caused by ASCAT's sensitivity to rough patches of ice which can appear similar to, but are not, MY ice.

Description: To improve knowledge of the wind loads on photovoltaic structures mounted on flat roofs at the high angles required in high latitudes, and to study starting flow on low aspect ratio wind turbine blades, a series of wind tunnel tests were undertaken. Thin flat plates of aspect ratios between 0.4 and 9.0 were mounted on a sensitive three-component instantaneous force and moment sensor. The Reynolds numbers varied from 6 × 104 to 2 × 105. Measurements were made for angles of attack between 0° and 90° both in the free stream and in wall proximity with increased turbulence and mean shear. The ratio of drag to lift closely follows the inverse tangent of the angle of incidence for virtually all measurements. This implies that the forces of interest are due largely to the instantaneous pressure distribution around the plate and are not significantly influenced by shear stresses. The instantaneous forces appear most complex for the smaller aspect ratios but the intensity of the normal force fluctuations is between 10% and 20% in the free-steam but can exceed 30% near the wall. As the wind tunnel floor is approached, the lift and drag reduce with increasing aspect ratio, and there is a reduction in the high frequency components of the forces. It is shown that the centre of pressure is closer to the centre of the plates than the quarter-chord position for nearly all cases.