Radiometric calibration of a dual-wavelength terrestrial laser scanner using neural networks

The Salford Advanced Laser Canopy Analyser (SALCA) is a unique dual-wavelength full-waveform terrestrial laser scanner (TLS) designed to measure forest canopies. This paper has two principle objectives, first to present the detailed analysis of the radiometric properties of the SALCA instrument, and second, to propose a novel method to calibrate the recorded intensity to apparent reflectance using a neural network approach. The results demonstrate the complexity of the radiometric response to range, reflectance, and laser temperature and show that neural networks can accurately estimate apparent reflectance for both wavelengths (root mean square error (RMSE) of 0.072 and 0.069 for the 1063 nm and 1545 nm wavelengths respectively). The trained network can then be used to calibrate full hemispherical scans in a forest environment, providing new opportunities for quantitative data analysis

Do Bat Gantries and Underpasses Help Bats Cross Roads Safely?

Major roads can reduce bat abundance and diversity over considerable distances. To mitigate against these effects and comply with environmental law, many European countries install bridges, gantries or underpasses to make roads permeable and safer to cross. However, through lack of appropriate monitoring, there is little evidence to support their effectiveness. Three underpasses and four bat gantries were investigated in northern England. Echolocation call recordings and observations were used to determine the number of bats using underpasses in preference to crossing the road above, and the height at which bats crossed. At gantries, proximity to the gantry and height of crossing bats were measured. Data were compared to those from adjacent, severed commuting routes that had no crossing structure. At one underpass 96% of bats flew through it in preference to crossing the road. This underpass was located on a pre-construction commuting route that allowed bats to pass without changing flight height or direction. At two underpasses attempts to divert bats from their original commuting routes were unsuccessful and bats crossed the road at the height of passing vehicles. Underpasses have the potential to allow bats to cross roads safely if built on pre-construction commuting routes. Bat gantries were ineffective and used by a very small proportion of bats, even up to nine years after construction. Most bats near gantries crossed roads along severed, pre-construction commuting routes at heights that put them in the path of vehicles. Crossing height was strongly correlated with verge height, suggesting that elevated verges may have some value in mitigation, but increased flight height may be at the cost of reduced permeability. Green bridges should be explored as an alternative form of mitigation. Robust monitoring is essential to assess objectively the case for mitigation and to ensure effective mitigation

Comfort, identity and fashion in the post-socialist city: Materialities, assemblages and context

This paper works at the intersection of three bodies of writing: theories relating to fashion, identity and the city; debate relating to urban materialities, assemblages and context; and cultural interventions advancing the study of post-socialism. Drawing on empirical research undertaken in Bratislava, Slovakia, we unpack a blurring of public and private space expressed through clothing. In contrast to elsewhere in the city, in Petržalka, a high-rise housing estate from the socialist period, widely depicted as anonymous and hostile since 1989, residents are renowned for wearing ‘comfortable’ clothes in order to ‘feel at home’ in public space. We describe the relationship between fashion, identity and comfort as an everyday ‘political’ response to state socialism and later the emergence of consumer capitalism. We argue, however, that by considering materialities, assemblages and context that studies of fashion and consumer culture can offer more complex political, economic, social, cultural and spatial analysis. To that end, we show how personal and collective consumption bound up with comfort and city life can be understood with reference to changing temporal and spatial imaginaries and experiences of claiming a material ‘right to the city’