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Remote sensing, promising tool of the future. Mária Szomolányi Ritvayné – Gabriella Frombach VITUKI CONSULT. MOKKA Conference, June 15. 2007. Remote Sensing (RS):. Images can be recorded from different sampling distance, in optional time and in the required wavelenght ranges
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Remote sensing, promising tool of the future Mária Szomolányi Ritvayné – Gabriella Frombach VITUKI CONSULT MOKKA Conference, June 15. 2007.
Remote Sensing (RS): Images can be recorded from different sampling distance, in optional time and in the required wavelenght ranges Large amount of data can be detected from wide area, in a short time Invisible phenomena can be monitored, as well Change of the phenomena can be tracked MOKKA Conference, June 15. 2007.
Benefits of RS • It does not have an affect on the target object • Lots of sensors are available depending on the required wavelenght ranges • Measurable, phisical data can be collected during the operation • Collected data can be integrated to databases storing complex and spatial information MOKKA Conference, June 15. 2007.
Basis of RS Electro-magnetics radiation from the space comes into contact with the elements of the ground surface passthrough (e.g. on water) reflect absorb Their rates depend on the type and the status of the ground surface Objects of the ground surface have different spectral features Objects and shapes reflect a differing way in every single spectral range Multispectral data acquisition is based on this concept MOKKA Conference, June 15. 2007.
Passive RS Passive sensors Active RS Active sensors Electro-magnetics radiation Its source is mainly the SUN Measurement of the radiation coming from the Sun and reflected by the ground surface, or emitted by the objects themselves – efficiency depends on the weather conditions (cameras, multispectral, hyperspectral and termal scanners) Both the source and the sensors are equiped on an airplane or a satellite (radars, lidars – distance meters) MOKKA Conference, June 15. 2007.
Electro-magnetics spectra (1) Only a part of the electro-magnetics spetra can be seen by the human eyes Short wavelenght range < 400 nm UV, x-ray, -ray Visible range: 400 – 800 nm Long wavelenght range : > 800 nm infrared-, micro-, radio-waves MOKKA Conference, June 15. 2007.
Electro-magnetics spectra (2) Radiation of the Earth Reflected solar radiation Spectrum of electro-magnetics waves Source: Dr.Csató,Éva2000 MOKKA Conference, June 15. 2007.
O p t i c a l WINDOW Micro-wave WINDOW Electro-magnetics spectra (3) Wavelenght ranges, where the absorption of the atmosphere is minimal, are calledWINDOWS Source:
Spectral reflection Presented by graphs spectral reflectance curves Each materials and surface shapes have a special reflectance curve due to their own different features Water Tree Soil Water content Forrás: David Landgrebe Source: Clay content Land cover Forrás: Buiten,1993 Source: MOKKA Conference, June 15. 2007.
Source: FVMMGI Airborne Hyperspectral RS (1) The multispectral and hyperspectral (HS) imaging technologies are the most advanced generation of the RS Advantages of the HS sensors: • Nowadays measurments are taken on hundreds of bands (VIS 400-900 nm, NIR 900-1700 nm) • Bandwidht < 10 nm • Bands are continual, RS is on a contiguous wave-lenght • Most of them are dual-camera (400-2400 nm) airborne sensor The HS imaging records the spatial and the spectral features of the samples Scanning the surface of the sample storing the image made by the matrix sensor Combination of the images „spectral datacube” HS information datablock MOKKA Conference, June 15. 2007.
Airborne Hyperspectral RS (2) Computer data-analysis Building of the spectral classes from information Predefined criteria „Learning process” of the system – SPECTRAL DATABANK Class Conditional Feature Extraction Classification of the information by pixels Statistical calculation Processing software - CLASSIFICATION System is already capable „to identify” the detected object. MOKKA Conference, June 15. 2007.
Scope of the possible application (1)Environment protection – agriculture – industry • Mapping of land uses • Detection of the landcover • Measurment of biomass • Assessment of the phyto-plankton and chlorophyll-a content of the surface waters (water pollution, eutrofization) • Status assessment of vegetation • Mapping of the soil surface and –status: • Soil water content • Mineral content • Extent and type of contamination • Investigation of the efficiency of remediation • Status assessment of pavement and infrastructures • Etc. MOKKA Conference, June 15. 2007.
Scope of the possible application (2) Complex environment protection and agricultural application Satellite and airborne data collection Building of a field specific spectral database Hyperspectral detection of contaminated areas Environmental data Transport modelling Forrás: FVMMGI
Thank you for attention! MOKKA Konferencia, 2007. június 15.