Introduction to Photogrammetry and GIS

Introduction to Photogrammetry and GIS

Photogrammetry is the science of obtaining reliable information about physical objects and the environment through the process of recording, measuring, and interpreting photographic images.

Aerial Photography

Photographs taken from an aircraft or drone.

• Vertical Photography: Camera axis is vertical or nearly vertical.
• Oblique Photography: Camera axis is intentionally tilted.

Scale of a Vertical Photograph ($S$)

$S = \frac{f}{H - h}$

Where:

• $f$: Focal length of the camera lens.
• $H$: Flying height of the aircraft above the datum (usually MSL).
• $h$: Elevation of the ground point above the datum.

Scale varies with ground elevation. Higher ground has a larger scale.

Geographic Information Systems (GIS)

A system designed to capture, store, manipulate, analyze, manage, and present all types of geographical data.

Components of GIS

1. Hardware: Computers, servers, scanners, plotters, GPS receivers.
2. Software: ArcGIS, QGIS, etc.
3. Data: Spatial data (coordinates, vectors) and Attribute data (tables).
   • Vector Data: Points, lines, and polygons.
   • Raster Data: Grid of cells (pixels), e.g., satellite imagery.
4. People: Users, analysts, developers.
5. Methods: Procedures and workflows.

Applications of GIS

• Urban Planning
• Environmental Management
• Transportation Network Analysis
• Emergency Response
• Natural Resource Management

Solved Problems