A Brief Introduction to Remote Sensing Satellites

Very brief introduction to remote sensing and satellite and its applications

1. ALIREZA RAHIZADEGANASL
Remote Sensing Satellites

2. What is Remote Sensing
Remote sensingisa
technologyusedforobtaining
informationabout the
characteristicsofanobject
throughtheanalysisofdata
acquiredfromitatadistance.
“themeasurementoracquisitionof
informationofsomepropertyofanobject
orphenomenon,byarecordingdevicethat
isnotinphysicalorintimatecontactwith
theobjectorphenomenonunderstudy”
(Colwell,1997).

3. An Overview
There is two broad categories of Remote Sensing based
on the platforms:
Aerial Remote Sensing
sensors are mounted on aircraft, balloons, rockets and
helicopters.
Satellite Remote Sensing
referred to as ‘eyes in the sky’.
brought a revolution in remote sensing field

4. Advantage of Satellite Remote Sensing to
Arial One
1.Continuousacquisitionofdata
2.Frequentandregularre-visitcapabilitiesresultingin
up-to-dateinformation
3.Broadcoveragearea
4.Goodspectralresolution
5.Semi-automated/computerizedprocessingandanalysis
6.Abilitytomanipulate/enhancedataforbetterimage
interpretation
7.Accuratedatamapping
hereafter,wheneverremotesensingismentioned,itwill
refertosatelliteremotesensingunlessotherwisestated.

5. Classification of Satellite Remote Sensing
Systems
Remotesensingsystemscanbeclassifiedonthetwo
basis:
a.Thesourceofradiation
1.Passiveremotesensingsystems
2.Activeremotesensingsystems
b.Thespectralregionsusedfordataacquisition
1.Opticalremotesensingsystems(includingvisible,nearIR
andshortwaveIRsystems)
2.Thermalinfraredremotesensingsystems
3.Microwaveremotesensingsystems

6. Passive remote sensing systems:
Passiveremotesensingsystemseitherdetectthesolarradiationreflected
bytheobjectsonthesurfaceoftheEarthordetectthethermalor
microwaveradiationemittedbythem.
Apassivesystemgenerallyconsistsofanarrayofsensorsor
detectorsthatrecordtheamountofelectromagneticradiation
reflectedand/oremittedfromtheEarth’ssurface.
Active remote sensing systems
Activeremotesensingsystemsmakeuseofactiveartificial
sourcesofradiationgenerallymountedontheremotesensing
platform.
Anactivesystem,ontheotherhand,emitselectromagnetic
radiationandmeasurestheintensityofthereturnsignal.
Classification of Satellite Remote Sensing
Systems

7. Both passive and active sensors can be further
classified as:
1.Scanning sensors
The field of interest scanned sequentially
2.Non-scanning sensors
The entire field of interest is explored in one take.
Classification of Satellite Remote Sensing
Systems

8. Scanning satellite remote
sensing system

9. Non-scanning satellite
remote sensing system

10. Classification of Satellite Remote Sensing
Systemsbasedon spectralregions
Optical Remote Sensing
Systems
Theimagesareformedbydetecting
thesolarradiationreflectedby
objectsontheground.
Opticalremotesensingsystems
mostlymakeuseofvisible(0.3--
0.7μm),nearIR(0.72--1.30μm)
andshortwaveIR(1.3--3.0μm)
wavelengthbandstoformimagesof
theEarth’ssurface.

11. Thermal Infrared Remote
Sensing Systems
Thermalinfraredremotesensing
systemsemploythemidwaveIR(3--5
μm)andthelongwaveIR(8--14μm)
wavelengthbands.Theimageryhereis
derivedfromthethermalradiation
emittedbytheEarth’ssurfaceand
objects.
Thermalimagesprovideinformationon
thetemperatureofthegroundand
watersurfacesandtheobjectsonthem.
Classification of Satellite Remote Sensing
Systems

12. Microwave Remote
Sensing Systems
Microwave remotesensing
systemsgenerallyoperateinthe
1cmto1mwavelengthband.
Microwave radiationcan
penetratethroughclouds,haze
anddust,makingmicrowave
remotesensingaweather
independenttechnique.
Activemicrowaveremotesensing
systemsprovidetheirownsource
ofmicrowaveradiationto
illuminatethetargetobject
Classification of Satellite Remote Sensing
Systems

13. Remote Sensing Satellite Orbits
Remotesensingsatelliteshavesun-synchronoussubrecurrentorbitsat
altitudesof700--900km,allowingthemtoobservethesamearea
periodicallywithaperiodicityoftwotothreeweeks.
Asanexample,theSPOTsatellitehasasun-synchronousorbitwithan
altitudeof820kmandaninclinationof98.7◦.Thesatellitecrossesthe
equatorat10:30a.m.localsolartime.

14. •Spatial:Thesizeofthefield-of-view,e.g.10x10m.
•Spectral:Thenumberandsizeofspectralregionsthesensor
recordsdatain,e.g.blue,green,red,near-infrared
thermalinfrared,microwave(radar).
•Temporal:howoftenthesensoracquiresdata,e.g.every30
days.
• Radiometric :the sensitivity of detectors to small differences
in electromagnetic energy.
10 m
BGRNIR
Jan
15
Feb
15
10 m
Remote Sensor Resolution
Resolutionofanyremotesensingsystemisspecifiedintermsofspectralresolution,
radiometricresolution,spatialresolutionandtemporalresolution.Thesearebriefly
describedasfollows:

15. Spatial Resolution
Imageryofresidential
housinginMechanicsville,
NewYork,obtainedon
June1,1998,atanominal
spatialresolutionof0.3x
0.3m(approximately1x1
ft.)usingadigitalcamera.
Jensen 2003

16. Jensen 2003

17. Spectral
Resolution
Jensen 2003

18. Spectral Resolution
AirborneVisibleInfrared
Imaging Spectrometer
(AVIRIS)Datacubeof
Sullivan’sIslandObtained
onOctober26,1998
Jensen 2003

19. TemporalResolution
June 1, 2006 June 17, 2006 July 3, 2006
Remote Sensor Data Acquisition
16 days
Jensen 2003

20. RadiometricResolution
8-bit
(0 -255)
9-bit
(0 -511)
10-bit
(0 -1023)
0
0
0
7-bit
(0 -127)
0

21. Passive Sensors
Optical Mechanical
Scanner
Thisisamultispectralradiometer(a
radiometerisadevicethatmeasuresthe
intensityoftheradiationemanatingfrom
theEarth’ssurface)wherethescanningis
doneinaseriesoflinesoriented
perpendiculartothedirectionofthe
motionofthesatelliteusingarotatingor
anoscillatingmirror

22. Passive Sensors
Push Broom Scanners
Apushbroomscanner(alsoreferredto
asalineararraysensororalong-track
scanner)isascannerwithoutany
mechanicalscanningmirrorbutwitha
lineararrayofsemiconductorelements
locatedatthefocalplaneofthelens
system,whichenablesittorecordone
lineofanimagesimultaneously

23. Active Sensors
Active Non-scanning Sensors
Activenon-scanningsensorsystemsincludemicrowavealtimeters,
microwavescatterometers,laserdistancemetersandlaserwater
depthmeters.
Active Scanning Sensors
Themostcommonactivescanningsensorusedisthesyntheticaperture
radar(SAR).Insyntheticapertureradarimaging,microwavepulsesare
transmittedbyanantennatowardstheEarth’ssurfaceandtheenergy
scatteredbacktothesensorismeasured.

24. Synthetic Aperture Radar (SAR)

25. Applications of Remote Sensing Satellites
Land Cover Classification
Land Cover Change Detection
Water Quality Monitoring and Management
Flood Monitoring
Urban Monitoring and Development
Measurement of Sea Surface Temperature
Deforestation
Global Monitoring
Predicting Disasters
Predicting Earthquakes
Volcanic Eruptions
Other Applications

26. Land Cover Classification

27. Land Cover Change Detection

28. Water Quality Monitoring and Management

29. Flood Monitoring

30. Urban Monitoring and Development

31. Measurement of Sea Surface Temperature

32. Deforestation

33. Global Monitoring

34. Major Remote Sensing Missions
Landsat Satellite System
Instrument Picture Launched Terminated Duration Notes
Landsat 1 July 23, 1972January 6, 1978
2years, 11months and
15days
Originally named Earth Resources
Technology Satellite 1.
Landsat 2
January 22,
1975
February 25,
1982
2years, 10months and
17days
Nearly identical copy of Landsat 1
Landsat 3 March 5, 1978March 31, 19835years and 26days
Nearly identical copy of Landsat 1
and Landsat 2

35. Major Remote Sensing Missions(Landsat)
Instrument Picture Launched Terminated Duration Notes
Landsat 4 July 16, 1982
December 14,
1993
11years, 4months and
28days
Landsat 5 March 1, 1984June 5, 2013
[7]
29years, 3months and
4days
Nearly identical copy of Landsat 4.
Longest Earth-observing satellite
mission in history.
Landsat 6
October 5,
1993
October 5, 1993 0 days Failed to reach orbit.

36. Major Remote Sensing Missions(Landsat)
Instrument Picture Launched Terminated Duration Notes
Landsat 7 April 15, 1999 Still active
16years, 11months and
15days
Operating with scan line corrector
disabled since May 2003.
[8]
Landsat 8
February 11,
2013
Still active
3years, 1month and
19days
Originally named Landsat Data
Continuity Mission from launch until
May 30, 2013, whenNASAoperations
were turned over toUSGS.
[9]

37. Major Remote Sensing Missions(Landsat)

38. Major Remote Sensing Missions
SPOT Satellite System
(satellite pour l’observation de la terre)
SPOT1launchedFebruary22,1986with10meterpanchromaticand20
metermultispectralpictureresolutioncapability.WithdrawnDecember31,
1990.
SPOT2launchedJanuary22,1990anddeorbitedinJuly2009.
SPOT3launchedSeptember26,1993.StoppedfunctioningNovember14,
1997.
SPOT4launchedMarch24,1998.StoppedfunctioningJuly,2013.
SPOT5launchedMay4,2002with2.5m,5mand10mcapability.
SPOT6launchedSeptember9,2012.
SPOT7launchedonJune30,2014

39. Major Remote Sensing Missions
Spot 5 (2.5m/5m)

40. Major Remote Sensing Missions
Spot 6 (1.5m)

41. Resolution at Nadir 0.82 meters panchromatic; 3.2 meters multispectral
Resolution 26°Off-Nadir 1.0 meter panchromatic; 4.0 meters multispectral
Major Remote Sensing Missions
IKONOS
The IKONOS satellite sensor was successfully launched as the first
commercially available high resolution satellite sensor
Launch Date
24 September 1999 at Vandenberg Air Force Base,
California, USA
Operational Life Over 7 years
Orbit 98.1 degree, sun synchronous

42. Major Remote Sensing Missions

43. Major Remote Sensing Missions

45. Any Question?

46. Thank You
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