Borstad Associates Ltd. - Image Display and Analysis Programs

Image Display and Analysis Programs

One of the major findings from the watershed study was that some of the watershed management organisations already use satellite imagery, but the majority reported that “satellite data are expensive, difficult to use and require expensive software and extensive staff training”.

This section addresses the cost and complexity of software issue.

Five projects are described later in this web site. They are to:

Acquire and print a satellite image of a southern Ontario watershed that looks like a colour air photograph and shows a level of detail equivalent to a 1:50,000 topographic map.
Overlay the image with various line maps, including catchment areas, streams, municipal boundaries, roads and, if it is feasible, to add highway numbers and stream names.
Acquire and print older satellite images from the early 1980’s, early 1990’s and compare them with the most recent image to illustrate changes in land use patterns throughout the watershed over the past 20 years.
If possible, make a three-dimensional model of the watershed that can be viewed from different angles on the computer.
Automatically calculate changes in the extent of built-up areas, agricultural land and in such natural features as forest cover.

The software used to implement the projects described later on this web site were chosen on the basis of low price and ease of use.

For simple image manipulation Jasc Paint Shop Pro 8 (about $150 Canadian) was used for Project 1. An alternative (among others) is Adobe PhotoShop ($1,000).

Manifold 5.5 (about $500 Canadian) was selected for Projects 1 to 4, but not Task 5.

Other, more complete image analysis and GIS programs, such as PCI Geomatica 9.1 (Fundamentals version costs about $3,250), ERMapper 6.4 (about $10,000) can be used for all five Tasks. Also, PCI Geomatica and ERMapper can read the Level 1G processed Landsat data in HDF format.

For GIS work, MapInfo Professional (about $2,000) is good choice for both novice and intermediate users.

This is not an exhaustive review of suitable software packages. Readers may have equivalent software already installed on the computers, or they may discover freeware that can perform the necessary tasks.