Detecting new Buffel grass infestations in Australian arid lands: evaluation of methods using high-resolution multispectral imagery and aerial photography

We assess the feasibility of using airborne imagery for Buffel grass detection in Australian arid lands and evaluate four commonly used image classification techniques (visual estimate, manual digitisation, unsupervised classification and normalised difference vegetation index (NDVI) thresholding) for their suitability to this purpose. Colour digital aerial photography captured at approximately 5 cm of ground sample distance (GSD) and four-band (visible–near-infrared) multispectral imagery (25 cm GSD) were acquired (14 February 2012) across overlapping subsets of our study site. In the field, Buffel grass projected cover estimates were collected for quadrates (10 m diameter), which were subsequently used to evaluate the four image classification techniques. Buffel grass was found to be widespread throughout our study site; it was particularly prevalent in riparian land systems and alluvial plains. On hill slopes, Buffel grass was often present in depressions, valleys and crevices of rock outcrops, but the spread appeared to be dependent on soil type and vegetation communities. Visual cover estimates performed best (r(2) 0.39), and pixel-based classifiers (unsupervised classification and NDVI thresholding) performed worst (r(2) 0.21). Manual digitising consistently underrepresented Buffel grass cover compared with field- and image-based visual cover estimates; we did not find the labours of digitising rewarding. Our recommendation for regional documentation of new infestation of Buffel grass is to acquire ultra-high-resolution aerial photography and have a trained observer score cover against visual standards and use the scored sites to interpolate density across the region

Innovation networks: problems and prospects (Russian case study)

The topologies of innovation network development in Russia are described in this article. Study was conductedin one of the Russian industrial leader JSC Academician M.F. Reshetnev "Information Satellite Systems". Theoretical approaches to the network nature and classification are revealed herein. Some characteristics of innovation network as relatedness, centrality, and intensity were discussed in the article."Information Satellite Systems" has a lot of branch and subsidiaries which form the innovation network of this enterprise. Research methodology consists of head of companies' survey and interview and analyses of open information of firm functioning. Results of research show the vertical hierarchaloriented innovation network with a low-degree of relatedness. Also anchor company ISS has a distinct network landscape with a focus on large vertically integrated, with a low degree of network connectivity, with the unexpressed (weak) links, where a key type of partnership is scientific collaboration with the base (dependent) subsidiary companies, universities and research institutes

Lehmann-Symanzik-Zimmermann S-Matrix elements on the Moyal Plane

Field theories on the Groenewold-Moyal(GM) plane are studied using the Lehmann-Symanzik-Zimmermann(LSZ) formalism. The example of real scalar fields is treated in detail. The S-matrix elements in this non-perturbative approach are shown to be equal to the interaction representation S-matrix elements. This is a new non-trivial result: in both cases, the S-operator is independent of the noncommutative deformation parameter $\theta_{\mu\nu}$ and the change in scattering amplitudes due to noncommutativity is just a time delay. This result is verified in two different ways. But the off-shell Green's functions do depend on $\theta_{\mu\nu}$. In the course of this analysis, unitarity of the non-perturbative S-matrix is proved as well.Comment: 18 pages, minor corrections, To appear in Phys. Rev. D, 201

Stripping away sky reflectance, waves and turbulence for benthic mapping: Imaging the seafloor not the surface

This paper presents the results of an airborne experiment using horizontal and vertical polarising filters on a pair of co-mounted 12.8 megapixel Canon 5D digital cameras. These cameras were mounted in the underside camera port of a light aircraft, both cameras inclined at 30 degrees off-nadir. One camera had the polarisation filter oriented vertically and the other oriented horizontally. Forward-looking, overlapping, oblique aerial photography was captured over known seagrass meadows off the Adelaide metropolitan coastline, plus inland urban water bodies. The portrait oriented field of view allowed a progression on the image from near-nadir to beyond the critical Brewster angle of 53 degrees. Results show the removal of sky reflectance, turbulence and wave action on the vertically-oriented filter imagery compared to the horizontally-oriented filter imagery in both clear and turbid waters. For clear waters the removal of sky reflectance, waves and surface turbulence allowed visualisation of the seafloor suitable for benthic mapping in areas of seagrass. However in turbid water the removal of surface effects still did not allow the seafloor to be visualised due to multiple scatter in the body of the water. This method therefore also has application in differentiating clear and turbid waters on oblique photography

Seeing seagrasses sidewards: marine angiosperms and the Stokes' polarization parameters

Mapping of marine benthic flora using remote sensing techniques has been used to assess the dynamics of environmental conditions in coastal areas. Mostly studies used panchromatic/colour aerial photography and/or medium resolution multispectral satellite imagery to create time series showing the change of seagrass distribution, as indicator species of environmental conditions. While successful within their project parameters, these studies were limited by conditions at time of image capture, such as sun-glare, turbidity, wave action and low contrast in deeper waters due to absorption and scattering. The use of polarized multispectral imagery has the potential to overcome, or at least reduce these problems such that a finer detail of benthic flora may become visible. This paper explores the theoretical background in the application of polarization for mapping seagrass and other marine benthic flora. It also discusses a possible operational design using a low cost airborne multispectral camera.David Hart, Megan Lewis, Bertram Ostendorf and Paul Darehttp://www.arspc.org/abstract/36.ht

Understanding the spatially variable effects of climate change on rice yield for three ecotypes in Bangladesh, 1981-2010

Climate change will impact on rice food security in many parts of the world, including Bangladesh. Little attention has been given to understanding the impact of climate on rice yield for three main ecotypes (Aus, Aman, and Boro) in different areas of the country. The aim of this paper was to analyse the spatiotemporal dynamics of rice yield and climatic variables and the spatially variable climate effects on rice yield for these ecotypes in Bangladesh during 1981-2010 by employing linear mixed models and generalized linear models. The results demonstrated the substantial spatiotemporal variations of rice yield for all ecotypes across the country. Rice yield for ecotypes was more susceptible to temperature changes than rainfall effects. Modelling of a 1°C temperature increase in the country showed strong regional differences in rice yield for these ecotypes. The study concludes that future temperature changes are likely to change regional rice yield for all ecotypes and hence impact food security. The results have important consequences for food security by indicating the need for appropriate region-specific adaptation measures to reduce rice yield variability in the future. The results show the need to consider spatial differences for policy development to improve food security in Bangladesh