EG2234: Earth Observation

Introduction to RSDr 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 = 200-48 = 152 hrs– Assignment requires 76 hrs of YOUR effort

Examination: is worth 50%– After Easter next year (requires 76 hrs of reading/prep)

www.ukscience.org

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 - 1990s: Rapid development of digital image processing

and launch of high resolution satellite sensors

The electromagnetic spectrum

All objects above absolute zero (-273.15ºC 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

GEOSTATIONARY POLAR ORBITER

Updates every hour updates twice a day

Low spatial resolution High spatial resolution

Used for weather prediction Used for monitoring

Sees only portion of Earth Global coverage

Geostationary Polar 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:

http://www.rspsoc.org/