Introduction to RemoteSensing of the Environment
Dr. Anne Nolin
Department of Geosciences
Overview of today’s lecture
• Course overview
• Definitions
• How measurements are made
• Analog vs. digital
• The remote sensing cycle
• Examples
Course Logistics• Lecture:
– MF 10:00-10:50AM
• Lab: – M 11:00 - 12:50PM (grad students)– W 10:00 - 11:50AM (undergrads)
• TA: Ofer Heyman ([email protected])• Course website:
http://www.geo.orst.edu/classes/geo444_544• Blackboard: lectures, etc. will be posted
Office Hours
Nolin:Tuesdays 1:00 - 2:00PM (Wilk 120)Wednesdays 1:00 - 2:00PM (Wilk 120)or by appointment
Heyman:Mondays 9:00AM-10:00PM (Wilk 210)Wednesdays 9:00-10:00AM (Wilk 223)or by appointment
Lab Exercises and Exams
• Labs exercises are assigned each week– due the beginning of next lab– must be submitted electronically– no credit for late work
• Exams:– Midterm: May 2– Final: June 9, 2:00 - 4:00 PM– exams are closed book
Labs will be held this week!
• See the course website for an overviewof this week’s lab
Graduate Student Project
• Remote sensing application relevant toyour area of research
• Submit short proposal to me by April 18• 2-page extended abstract due June 2• Conference-style poster presentation on
June 6• All students must attend these
presentations on June 6th
20%-0-Term Project
30%35%Labs
20%35%Final
30%30%Midterm
GEO544GEO 444Grading
Physical Principles of Electromagnetic RadiationHow satellites and sensors workOptical remote sensingThermal remote sensingPassive microwave remote sensingActive microwave remote sensingLidar and altimetryApplications: Vegetation mappingApplications: Land cover/land use changeApplications: WaterApplications: Soils, minerals, and geomorphologyApplications: Urban mapping
What is remote sensing?“the acquisition and measurement of data/informationon some property(ies) of a phenomenon, object, ormaterial by a recording device not in physical,intimate contact with the features(s) undersurveillance; techniques involve amassing knowledgepertinent to environments by measuring force fields,electromagnetic radiation, or acoustic energyemploying cameras, radiometers and scanners, lasers,radio frequency receivers, radar systems, sonar,thermal devices, seismographs, magnetometers,gravimeters, scintillometers, and other instruments”.
Source: NASA tutorial on remote sensinghttp://rst.gsfc.nasa.gov/Intro/nicktutor_I-1.html
Shorter definition
• Remote sensing is the collection ofinformation about an object or systemwithout coming into direct physicalcontact with it
• Art or science???
Why do we do remote sensing?
• Unobtrusive• Automated• Useful for extreme conditions• Offers excellent spatial and temporal
coverage• Often cost-effective• Extends our senses
How are measurements made?
• Ground-based
• Airborne
• Satellite
Remote Sensing Systems• Active Sensor - illuminates the subject from an
artificial energy source
• Passive Sensor - uses natural radiation fromthe Sun or other emitted signal
• Imaging Sensor - creates a “picture” byscanning across linear array of detectors whilethe array moves through space
• Non-imaging Sensor - measures along atransect or at a point
REMOTE SENSING DATA TYPES
Visible, infrared, thermal, and microwave are most common
Analog vs. Digital
What is analog data?– Film
Benefits of analog data:– Easy to view– High spatial resolution– Often very cost effective– Compact (photograph vs. hard drive, CDs,
or tape)
Drawbacks of analog data:– Difficult to transmit remotely
– Difficult to edit after acquisition
– Limited response to light (visible andnear infrared wavelengths only)
– Degradation over time can limitarchive capabilities
Benefits of digital data:– Wide variety of detectors
• Electromagnetic and other types• Large amplitude range
– Data easily transmitted remotely– Data easily edited by computer after
acquisition– Longterm archive
Drawbacks of digital data– Storage requirements can be large
– Requires sophisticated equipment toview
– Reduced spatial resolution (in mostcases)
The Remote Sensing Cycle
Sensor
Data
Processing
DataAnalysisInterpretation
Information
Assessment
Development
The Remote Sensing Cycle
Sensor
Data
Processing
DataAnalysisInterpretation
Information
Assessment
Development
Montana Fires, August 23 2000MODIS thermal bandsare used to map thelocation and strength of activefires, and burned areaextent.
Vegetation maps alsoprovide informationabout fire dynamics
Smoke plumes canbe tracked forhealth monitoringFires superimposed on MODIS 250m
surface reflectance product
Breakup of the Larsen B Ice Shelf
MODISimagery fromJanuary 31, 2002-March 6, 2002
Courtesy of Ted Scambos, NSIDC
GeologicMapping
withAVIRIS
Mapping the 1996 Oregon Floods
RADARSAT image 13 FebColumbia River near Portlandjust past peak flood stage.
RADARSAT image 14 Febshowing flood damaged areas
MiningWaste inLeadville,
CO
AVIRIS imageshowing distributionand types of acid-generating minerals
Lambert Glacier, Antarctica
InterferometricSyntheticAperatureRadar (InSAR)uses phasedifferencebetween twoimages todeterminemovement
Image courtesy CSA, NASA, Ohio State Univ., JPL, ASF
Wetlands ofthe Gulf Coast
Multispectral andmultiangular viewsof coastal wetlands offthe coast of Louisiana
MISR