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Hyperspectral Sensor Data Capability for Retrieving Complex Urban Land Cover in Comparison with Multispectral Data: Venice City Case Study (Italy)

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ABSTRACT

This study aims at comparing the capability of different sensors to detect land cover materials within an historical urban center. The main objective is to evaluate the added value of hyperspectral sensors in mapping a complex urban context. In this study we used: (a) the ALI and Hyperion satellite data, (b) the LANDSAT ETM+ satellite data, (c) MIVIS airborne data and (d) the high spatial resolution IKONOS imagery as reference. The Venice city center shows a complex urban land cover and therefore was chosen for testing the spectral and spatial characteristics of different sensors in mapping the urban tissue. For this purpose, an object-oriented approach and different common classification methods were used. Moreover, spectra of the main anthropogenic surfaces (i.e. roofing and paving materials) were collected during the field campaigns conducted on the study area. They were exploited for applying band-depth and sub-pixel analyses to subsets of Hyperion and MIVIS hyperspectral imagery. The results show that satellite data with a 30m spatial resolution (ALI, LANDSAT ETM+ and HYPERION) are able to identify only the main urban land cover materials.

No MeSH data available.


Object-oriented approach results of MIVIS data (8m/pixel).
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f4-sensors-08-03299: Object-oriented approach results of MIVIS data (8m/pixel).

Mentions: The segmentation approach usually allows to: (a) quantify the spatial heterogeneity within the data at different scale levels; (b) delineate uniform patches; (c) implement a hierarchal structure between segments at different spatial scales. For this case study, however, the satellite spatial resolutions (30m/pixel) appear too low with respect to the urban texture and results of the object-oriented approach are extremely poor for all the satellite data. Good results, instead, were observed for the MIVIS (8m/pixel) airborne classification, for which it was even possible to discriminate different vegetation cover types, i.e. conifers, broad leaves and grass (Figure 4).


Hyperspectral Sensor Data Capability for Retrieving Complex Urban Land Cover in Comparison with Multispectral Data: Venice City Case Study (Italy)
Object-oriented approach results of MIVIS data (8m/pixel).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3675545&req=5

f4-sensors-08-03299: Object-oriented approach results of MIVIS data (8m/pixel).
Mentions: The segmentation approach usually allows to: (a) quantify the spatial heterogeneity within the data at different scale levels; (b) delineate uniform patches; (c) implement a hierarchal structure between segments at different spatial scales. For this case study, however, the satellite spatial resolutions (30m/pixel) appear too low with respect to the urban texture and results of the object-oriented approach are extremely poor for all the satellite data. Good results, instead, were observed for the MIVIS (8m/pixel) airborne classification, for which it was even possible to discriminate different vegetation cover types, i.e. conifers, broad leaves and grass (Figure 4).

View Article: PubMed Central

ABSTRACT

This study aims at comparing the capability of different sensors to detect land cover materials within an historical urban center. The main objective is to evaluate the added value of hyperspectral sensors in mapping a complex urban context. In this study we used: (a) the ALI and Hyperion satellite data, (b) the LANDSAT ETM+ satellite data, (c) MIVIS airborne data and (d) the high spatial resolution IKONOS imagery as reference. The Venice city center shows a complex urban land cover and therefore was chosen for testing the spectral and spatial characteristics of different sensors in mapping the urban tissue. For this purpose, an object-oriented approach and different common classification methods were used. Moreover, spectra of the main anthropogenic surfaces (i.e. roofing and paving materials) were collected during the field campaigns conducted on the study area. They were exploited for applying band-depth and sub-pixel analyses to subsets of Hyperion and MIVIS hyperspectral imagery. The results show that satellite data with a 30m spatial resolution (ALI, LANDSAT ETM+ and HYPERION) are able to identify only the main urban land cover materials.

No MeSH data available.