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Learning Zone
Welcome to the Learning Zone. In the Zone you will find a series of lectures and other materials to guide you through the fundamental principles of remote sensing and photogrammetry with links to other pages and sites that will give you more information. You will find a number of case studies on ways that remote sensing and photogrammetry can be used to solve a variety of problems as well as teaching materials that you can use to help you learn about Earth Observation data and how you can analyse it to extract information.
What is Photogrammetry? Photogrammetry is the art, science and technology of obtaining reliable information about physical objects and the environment through processes of recording, measuring and interpreting photographic images and patterns of recorded radiant electromagnetic energy and other phenomena (Wolf and Dewitt, 2000).
There are two distinct categories of photogrammetry, Metric photogrammetry enables quantitive analysis of objects for determination of parameters such as length, area, elevation and volume and the most common applications for this type of analysis are the production of topographic and planimetric maps and productions of orthophotographs. Interpretive photogrammetry allows qualitative analysis of images providing information regarding the recognition and identification of objects and their significance with respect to the particular application.
What is Remote Sensing? Remote sensing is the science of measuring or inferring the physical properties of an object or medium, using a sensor that is at some distance from the object or medium. Typically, the term is used to describe measurements of electromagnetic radiation scattered or emitted from the Earth’s atmosphere or surface using instruments on aircraft or satellites. A more general definition would also include measurements of acoustic waves, magnetic fields and gravity, and would also encompass measurements of other planets or moons in the solar system using interplanetary probes. The term Earth Observation is now also in widespread use, but its use is normally restricted to describing regional-to-global scale measurements from satellites. More recently, however, the Group on Earth Observations has broadened this term to include ”...the collection, processing, modelling, and dissemination of data about the Earth system… collected through in situ, airborne and space-based observations, using satellites, buoys, seismometers, and other devices” (Woodhouse, 2006).
What Is a Geographic Information System (GIS)? GIS is technology that views and analyses data from a geographic perspective. It links geographic location with descriptive information and facilitates the presentation of multiple layers of different information in a digital map that enables us to create, access, manage and analyse this information. Remote Sensing data processed using Photogrammetry forms an important part of a GIS as it proivides the geographic platform that descriptive information sits on.
