Hyperspectral imagery for Environmental urban Planning

Informations

Funding country

France

Acronym

HYEP

URL

-

Start date

12/1/2014

End date

-

Budget

505,484 EUR

Fundings

Abstract

World population gathers in urban areas restructuring at the local and regional levels the urban territories. These spaces are characterized by paradoxical process on the one hand a sprawl at the expense of natural and agricultural ecosystems and on the other hand a densification of the urban fabric. These combined processes have impacted the climate characteristics of local and regional scales (Shafri et al. 2012), as well as biotic and abiotic processes (Voogt and Oki, 2003). Needs for more information followed these developments, reinforced by the emergence of logics of sustainable development at different spatial scales. Current satellite data provide limited information, features urban complicating their use, by the strong internal dynamic, spatial heterogeneity of the elements, geometric shapes (horizontal and vertical), variety of materials and presence of shadow. Mapping of surfaces, state of vegetation, follow-up of the ageing of materials, characterization of plant biodiversity (Miller & Small, 2003) covering strong fields of investigation. Various works show the contribution of hyperspectral compared the multispectral imagery. For Platt and Goetz (2004) the performance of the classification of urban surfaces obtained with images acquired by the spectro-imager Aviris are superior to those obtained with Landsat ETM + data. More recently. Tan and Wang (2007) assess the gain made by the hyperspectral instrument CHRIS/PROBA on the classification and use of urban areas from ASTER (3 bands VISNIR) data. Several authors (Chen, 2008) illustrate the limitations of multi-spectral sensors for the characterization of the impervious surfaces from hyperspectral imagery. The identification of plant species and vegetation (Mc Kinney, 2002) health survey can be an asset for the greenways. The richness and complexity of materials and forms in urban centres require specific spectral characteristics ranging from the visible to the SWIR (< 2.5 µm). Herold et al. (2003), has shown that spectrometers provides a high continuous spectral domain spectral resolution better identify (compared to usual sensors) and spatial information on soils, vegetation and materials (Chen, 2008, Pascucci et al 2010). The average size of urban objects lies between 10 and 20 m (Cutter et al. 2004). Also, a resolution of 5 m or better is considered necessary for a representation of urban objects (buildings, roads), vegetation (Jansen et al. 2012), or the planning of the territory (Wania & Weber, 2007). The contribution of the EnMAP data in a context of development and urban planning was recently studied by Heldens et al. (2011), but the spatial resolution of 30 m provides inadequate information at the district level. Taking into account geometric environment characteristics, the capacity of an instrument as HYPXIM combining high-resolution spectral (hyperspectral imaging) and spatial (panchromatic Imaging) information should allow to study objects of less than 5 m with a capacity to cover the spectral range 0.4 to 2.5 µm. Hyperspectral imaging may thus lift some of the identified locks but requires better understanding of the specificities of urban system and its elements (geometry spectral properties). This project is designed to justify the mission HYPXIM (french hyperspectral sensor) compared to the existing and future missions, define ways of treatments to use these images and constitute a morpho-spectral database adapted to these various missions.