Remote sensing, promising Remote sensing, promising tool of the futuretool 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 Images can be recorded from different sampling

distance, in optional time and in the required distance, in optional time and in the required

wavelenght rangeswavelenght ranges

Large amount of data can be detected from wide Large amount of data can be detected from wide

area, in a short timearea, in a short time

Invisible phenomena can be monitored, as wellInvisible phenomena can be monitored, as well

Change of the phenomena can be trackedChange of the phenomena can be tracked

MOKKA Conference, June 15. 2007.

It does not have an affect on the target objectIt does not have an affect on the target object

Lots of sensors are available depending on the required Lots of sensors are available depending on the required

wavelenght ranges wavelenght ranges

Measurable, phisical data can be collected during the Measurable, phisical data can be collected during the

operationoperation

Collected data can be integrated to databases storing Collected data can be integrated to databases storing

complex and spatial informationcomplex and spatial information

Benefits of RS

MOKKA Conference, June 15. 2007.

Electro-magnetics radiation from the space comes into Electro-magnetics radiation from the space comes into contact with the elements of the ground surfacecontact with the elements of the ground surface

Basis of RS

reflectreflect

absorbabsorb

passpass throughthrough(e.g. on water)

Their rates depend on the type and the status of the ground surfaceTheir rates depend on the type and the status of the ground surface

Objects of the ground surface have different spectral featuresObjects of the ground surface have different spectral features

Objects and shapes reflect a differing way in every single spectral Objects and shapes reflect a differing way in every single spectral rangerange

Multispectral data acquisition is based on this conceptMultispectral data acquisition is based on this concept

MOKKA Conference, June 15. 2007.

Electro-magnetics radiation

Its source is mainly the SUNIts source is mainly the SUN

Passive RS

Passive sensorsPassive sensors

Active RS

Active sensorsActive sensors

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 nmUV, x-ray, -ray

Visible range: 400 – 800 nmVisible range: 400 – 800 nm

Long wavelenght range : > 800 nminfrared-, micro-, radio-waves

MOKKA Conference, June 15. 2007.

Electro-magnetics spectra (2)

Source: Dr. Csató, Éva 2000 MOKKA Conference, June 15. 2007.

Radiation of the Earth

Reflected solar radiation

Spectrum of electro-magnetics waves

Electro-magnetics spectra (3)

Wavelenght ranges, where the absorption of the atmosphere is minimal, are called

WINDOWSWINDOWS

O p t i c a l WINDOWO p t i c a l WINDOW Micro-waveMicro-wave WINDOWWINDOW

Source:

Presented by graphs spectral reflectance curves

Each materials and surface shapes have a special reflectance curve due to their own different features

Spectral reflection

Forrás: David Landgrebe

Forrás: Buiten,1993 Land coverLand cover

Clay contentClay content

Water contentWater content

MOKKA Conference, June 15. 2007.

Source:

Source:

WaterTreeSoil

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 continualcontinual, RS is on a contiguous contiguous wave-lenght Most of them are dual-camera (400-2400 nm) airborne sensor

Airborne Hyperspectral RS (1)

The HS imaging records the spatial and the spectral features of The HS imaging records the spatial and the spectral features of the samplesthe samples

Cél Objektív lencse

ImSpector Mátrix detektor Térbeli tengely

Sp

ek

trá

lis

te

ng

ely

Lencsék és PGP alkotók Bemenet

Source: FVMMGI

Scanning the surface of the sample storing the image made by the matrix sensor

Combination of the images

„spectral datacube”

HS information HS information datablockdatablock

MOKKA Conference, June 15. 2007.

Airborne Hyperspectral RS (2)

Building of the spectral classes from information

Computer data-analysis Predefined criteria

„Learning process” of the system – SPECTRAL DATABANKSPECTRAL DATABANK

Classification of the information by pixels

Statistical calculation

Class Conditional

Feature Extraction

Processing software - CLASSIFICATION CLASSIFICATION

System is already capable „to identify” the detected object.

MOKKA Conference, June 15. 2007.

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 contaminationExtent and type of contamination• Investigation of the efficiency of Investigation of the efficiency of

remediationremediation

Status assessment of pavement and infrastructures

Etc.

Scope of the possible application (1) Environment protection – agriculture – industry

MOKKA Conference, June 15. 2007.

Environmental Environmental

datadataTransport modellingTransport modelling

Satellite and Satellite and airborne airborne

data data collectioncollection

Building of a field specific Building of a field specific spectral databasespectral database

Hyperspectral detection Hyperspectral detection of contaminated areasof contaminated areas

Scope of the possible application (2) Complex environment protection and agricultural application

Forrás: FVMMGI

Thank you for Thank you for attention!attention!

MOKKA Konferencia, 2007. június 15.