International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B7, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
ANALYSIS OF CONCRETE REFLECTANCE CHARACTERISTICS USING
SPECTROMETER AND VNIR HYPERSPECTRAL CAMERA
Jin-Duk Lee **, Bon A. Dewitt®, Sung-Soon Lee °, Kon-Joon Bhang *, Jung-Bo Sim *
a School of Civil and Environmental Engineering, Kumoh National Institute of Technology, 730-701 Gumi, Korea -
jdlee@kumoh.ac.kr, bhang. | @kumoh.ac.kr, mungmungmungv@hanmail.net
^ School of Forest Resources and Conservation, University of Florida, FL32611, Gainesville, United States -
bon@ufl.edu
° Korea Institute of Geoscience and Mineral Resources, 305-350 Daejeon, Korea - gisyi@kigam.re.kr
Commission VII, WG VII/3
KEY WORDS: Hyperspectral Images, Spectrometer, VNIR Hyperspectral Camera, Reflectance Spectra, Concrete Structures
ABSTRACT:
The purpose of this research is to extract spectral reflectance characteristics of concretes through basic experiment on concrete
specimens and site experiment on actual concrete structures using a field portable spectrometer and a VNIR hyperspectral sensor. À
spectrometer (GER-3700) and a VNIR hyperspectral camera (AisaEagle VNIR Hyperspectral Camera) were utilized for extracting
spectral characteristics of concrete specimens and actual concrete structures. General concretes show similar pattern with correlation
more than 80%, while super high strength concrete shows very different aspect from general concretes.
The GER-3700 spectrometer and the VNIR camera were applied to extracting spectral characteristics of the actual concrete
structures such as a bridge slab and pier in road construction site. We also made certain in not only interior experiment on concrete
specimens but also site experiment on actual concrete structures that both the spectrometer and the VNIR camera vary in spectral
reflectance depending on concrete strength. Afterwards if the studies on hyperspectral characteristics of worn-out concretes,
concrete aggregate condition diversity, super high-strength concretes are performed in depth, it is helpful in stability evaluation and
maintenance management of concrete-based structures or facilities using airborne or satellite hyperspectral images for a wide area.
1. INTRODUCTION
Recently necessity of system development and improvement
related to concrete characteristics is recognized largely with
regulation establishment for maintenance of concrete facilities
in construction markets. Concrete structures has been
continuously increased with industrial development and along
with this, structural monitoring techniques has been advanced.
We set to work on this research based on the idea that
hyperspectral remote sensing also might be utilized for
monitoring concrete structures. If spectral characteristics
according to concrete conditions can be understood,
hyperspectral imagery may be applied as a useful instrument for
surveying the current state for a number of concrete structures
or facilities distributed in an urban area.
Hyperspectral imagery has been used to detect and map a wide
variety of materials having characteristic of reflectance spectra.
For example, hyperspectral images have been used by
geologists for mineral mapping (Clark et al., 1995) and to detect
soil properties including moisture, organic content, and salinity
(Ben-Dor, 2001). Vegetation scientists have successfully used
hyperspectral imagery to identify vegetation species(Clark et al.,
1995), study plant canopy chemistry, and detect vegetation
stress. Military personnel have used hyperspectral imagery to
detect military vehicles under partial vegetation canopy, and
many other military target detection objectives (Peg Shippert,
2003). Lately Yavari et al.(2010) evaluated quality changes of
heated oils based on visible/near infrared spectral analysis using
a spectrometer. The use of reflectance spectroscopy across the
visible near- and short-infrared spectral region (400 to 2500
nm) was suggested as a tool to assess the status of concrete in
situ(Anna Brook and Eyal Ben-Dor, 2011).
The purpose of this research is to extract spectral reflectance
characteristics of concretes through basic experiment and on-
site experiment using a spectrometer and a VNIR hyperspectral
sensor. In this research, a spectrometer (GER-3700) and a
VNIR hyperspectral camera (AisaEagle VNIR Hyperspectral
Sensor) were utilized for extracting spectral characteristics of
concrete specimens and actual concrete structures.
2. BASIC EXPERIMENT FOR EXTRACTING
HYPRSPECTRAL CHARACTERISTICS OF
CONCRETES
2.1 Extracting Spectral Characteristics of Concrete
Specimens Using Spectrometer
For understanding characteristics of concretes, the concrete
specimens for compressive strength test were produced not only
with different water/cement ratio but also with different
concrete curing time. The design compressive strengthes of
eight specimens of general concrete were 15MPa(22),
*Jin-Duk Lee, School of Civil and Environmental Engineering, Kumoh National Institute of Technology,
jdlee@kumoh.ac.kr
