EG2234: Earth Observation Introduction to RS Dr Mark Cresswell

Topics Introduction to the unit and Assignment 1 RS – A definition Historical perspective Types of platform Satellite remote sensing Reading

About the Unit Lectures in E244 – Week by week listing in your handbooks & WEBCT Practicals/Seminars – Lab pracs in E409 (Thursdays 12am – 2pm) Assignment: is worth 50% – Approx 48 hours contact (in-class) time – Independent student learning = = 152 hrs – Assignment requires 76 hrs of YOUR effort Examination: is worth 50% – After Easter next year (requires 76 hrs of reading/prep)

What is Remote Sensing? A Definition: Remote sensing is the practice of deriving information about the earth’s land and water surfaces using images acquired from an overhead perspective, using electromagnetic radiation in one or more regions of the electromagnetic spectrum, reflected or emitted from the earth’s surface. Campbell, 1996

What is Remote Sensing? A Definition: Remote sensing is the practice of deriving information about the earth’s land and water surfaces using images acquired from an overhead perspective, using electromagnetic radiation in one or more regions of the electromagnetic spectrum, reflected or emitted from the earth’s surface. Campbell, 1996

What is Remote Sensing? Milestones in RS history: 1800:Discovery of infrared by Sir William Herschel 1839:Beginnings of photography 1850:Aerial photography using balloons 1909:Photography from aircraft 1972:Launch of Landsat 1970s s: Rapid development of digital image processing and launch of high resolution satellite sensors

The electromagnetic spectrum All objects above absolute zero ( ºC or 0ºK) emit electromagnetic radiation Radiation is detected by a radiometer

The electromagnetic spectrum Nuclear reactions occur within the Sun which emits ER across a broad range of wavelengths called a spectrum Some regions of this spectrum are visible (visible light) and some are invisible (infrared or ultraviolet) Remote sensing relies on the measurement of this radiation

Types of platform Aircraft Satellite Balloon Rocket Orbiting spacecraft Most common is the satellite

Satellite remote sensing in detail Orbiting satellites have different strategies according to their purpose Polar orbiters provide high resolution imagery for local studies Geostationary satellites provide high temporal resolution for large area studies

Satellite remote sensing in detail GEOSTATIONARYPOLAR ORBITER Updates every hourupdates twice a day Low spatial resolutionHigh spatial resolution Used for weather predictionUsed for monitoring Sees only portion of EarthGlobal coverage

GeostationaryPolar Orbiter

AVHRR 29/11/01 13:39 < VIS IR >

Meteosat: 29/11/2001 at 12:00z

Urban-Rural fringe

Oil Slick Detection

NDVI Monitoring Habitat modelling Hydrology

GIS and Models Remotely sensed data may be analysed and modelled within a GIS Decision-making and landscape analysis is easier when data is used intelligently Applications such as hydrology, agriculture, environmental change and coastal zone management use RS/GIS routinely

Summary Remote sensing allows earth surfaces to be continuously monitored Change detection becomes easier More cost effective than ground surveys Environment can be modelled when RS data is combined within a GIS with other relevant information

Reading International Journal of Remote Sensing Remote Sensing of the Environment The Remote Sensing and Photogrammetry Society website: