International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B4, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
CONTRIBUTION OF THE NEW WORLDVIEW-2 SPECTRAL BANDS FOR URBAN 
MAPPING IN COASTAL AREAS: CASE STUDY SAO LUIS (MARANHAO STATE, 
BRAZIL) 
Ulisses D. V. Souza ?, Hermann. J. H. kux ® 
* INPE - National Institute for Space Research, Avenida dos Astronautas, 1758 - Jardim da Granja, 12.227-010 Sao José dos 
Campos — SP, Brazil. (ulisses@dsr.inpe.br, hermann@ltid.inpe.br) 
Commission IV/3: Mapping from High Resolution Data 
KEY WORDS: WorldView-2; High resolution images; Urban areas; Coastal zone; Sáo Luis; Maranhio State. 
ABSTRACT: 
The objective of this study is to verify the contribution of the spectral bands from the new WorldView-2 satellite for the extraction 
of urban targets aiming a detailed mapping from the city of Sao Luis, at the coastal zone of Maranháo State, Brazil. This satellite 
system has 3 bands in the visible portion of the spectrum and also the following 4 new bands: Coastal (400-450 nm), Yellow (585- 
625 nm), Red Edge (705-745 nm), and Near Infrared 2 (860-1040 nm). As for the methodology used, initially a fusion was made 
among the panchromatic and the multispectral bands, combining the spectral information of the multispectral bands with the 
geometric information of the panchromatic band. Following the ortho-rectification of the dataset was done, using ground control 
points (GCPs) obtained during field survey. The classification reached high values of Kappa indices. The use of the new bands 
Red Edge and Near Infrared 2, allowed the improvement of discriminations at tidal flats, mangrove and other vegetation types. The 
Yellow band improved the discrimination of bare soils — very important information for urban planning — and ceramic roofs. The 
Coastal band allowed to map the tidal channels which cross the urban area of Sáo Luis, a typical feature of this coastal area. The 
functionalities of software GEODMA used, allowed an efficient attribute selection which improved the land cover classification 
from the test sites. The new WorldView-2 bands permit the identification and extraction of the features mentioned, because these 
bands are positioned at important parts of the electromagnetic spectrum, such as band Red Edge, which strongly improves the 
discrimination of vegetation conditions. Combining both higher spatial and spectral resolutions, WorldView-2 data allows an 
improvement on the discrimination of physical characteristics of the targets of interest, thus permitting a higher precision of land 
use/land cover maps, contributing to urban planning. The test sites of this study represent the main problem areas involving the 
city of Säo Luis and the entire region of the Maranhäo Island. 
1. INTRODUCTION (400-450 nm), Yellow (585-625 nm), Red Edge (705-745 nm), 
Near Infrared 2 (860-1040 nm) (DIGITALGLOBE, 2010a). 
With the advancement of remote sensing technologies and the The four bands mentioned, located at specific sections of the 
availability of sensor systems with improved spatial and electromagnetic spectrum, increase de discrimination capacity 
spectral resolution new applications became possible (Ehlers, and the analysis of targets under study (Figure 1). 
2007). 
After data from satellite WorldView-II, launched in October * C 
2009, became available, detailed analysis of coastal urban 
areas are possible, considering the high spatial resolution 
(0.46m in the panchromatic band and 1.84m in the 
multispectral bands). 
In order to work with these huge datasets, new methodologies 
were tested and applied. OBIA (Object-based image analysis) 
is a new paradigm considered for the classification of land 
cover in urban areas based on images with very high spatial 
resolution (BLASCHKE & KUX, 2007). 
  
356 450 see 550 750 850 956 1050 
Wavefength (nun 
The area under study, located at the northern section of 
Maranhäo Island presents a diversity of coastal habitats, such Figure 1 — Spectral response of Worldview II bands. 
as: mangroves, cliffs, beaches and tidal flats (so-called Source: Digital Globe (2010b) 
"apicum") which need a frequent monitoring because these are 
environmental protection areas sensitive to changes by human Souza et al, (2011) performed tests to improve the 
activities. discrimination of vegetation types at coastal areas, such as 
mangroves and tidal flats (so-called *apicuns") using the new 
The objective of this work is to analyze and test the 8 WorldView-2 bands. Applications of these bands as well as 
multispectral bands of WorldView-II satellite to identify and proposals of methodologies for its analysis, including spatial 
extract typical features of this coastal and urban environment. data analysis and OBIA, are found in Kerr (2011) and Vaduva 
This satellite system presents 3 bands in the visible spectrum (2011). 
and 2 in the near infrared, besides four new bands: Coastal 
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