The Canadian Remote-Sensing Program

Abstract

The principal elements in the Canadian national program in remote sensing are:

• The ERTS receiving station in Prince Albert,

• ERTS and airborne data processing facility in Ottawa,

• ERTS and airborne photographic reproduction facility in Ottawa,

• The airborne program,

• The remote-sensing test sites,

• The sensor development program,

• Regional and speciality interpretation centres,

• The necessary organization to manage the national program in remote sensing.

The Canada Centre for Remote Sensing (CCRS) has three operating Divisions: The Data Acquisition Division, the Data Processing Division, and Applications Division. New sensors are developed by the Centre with contracts to industry and universities. Photographic reproduction and distribution is handled by the National Air Photo Library (NAPL) of the Department of Energy, Mines and Resources.

Canada designed and constructed her own ERTS ground receiving station at Prince Albert, Saskatchewan. It was put there because of the existing 26 m diameter antenna, near the middle of the country. Data from the extreme east of Canada are not received at Prince Albert. There are plans for an east-coast station.

A quick-look display system has been incorporated into the Prince Albert station. It comprises a high-quality television display and a 70 mm camera. Prints from these negatives and microfiche copies of them (ERTSFICHE) are produced under a franchise arrangement and mailed out within two days of the satellite pass. About 70 ERTS images of Canada a day are received at Prince Albert. A tape record of the raw ERTS data is made and sent for processing to Ottawa.

This tape is handled by the Ottawa ERTS data processing facility. 70 mm monochrome images of each of the four ERTS-I multi-spectral scanner wave bands and computer-compatible tapes are produced by the facility. PDP-10 computers are also utilized for image inventory, the image analysis research of the Applications Division of CCRS, and processing airborne data.

An inventory of ERTS images is compiled in the CCRS computer as they are created together with comments on cloud cover and quality. Orders for the images are received by NAPL, checked against the computer inventory, and filled as soon as possible. The average time to filling such orders was about four weeks in December 1973, though fluctuations in service and back-log problems occur owing to occasional equipment malfunctions. An experimental regional capability of quizzing the image file is being considered. This consists of a remote terminal to the CCRS PDP-10 computer which can operate from any telephone.

The photographic products, in both colour and monochrome, maintain the full resolution of the ERTS system. NAPL also handle the reproduction and distribution of all airborne remote-sensing data from the full range of multi-spectral information present in the tapes.

CCRA has four aircraft equipped with a wide range of photographic sensors, far-infrared scanners and radiometers, and some newly developed special-purpose sensors such as a chlorophyll spectrometer, a laser fluorosensor, and a microwave scatterometer and radio-meter. These are available across Canada on a partial cost-recovery basis. Over the past three years, a series of research and development contracts to construct new equipment for clearly defined needs such as sea-ice thickness measurement, have been let by CCRS to Canadian industry and universities.

The Provinces of Ontario, British Columbia, Manitoba, and Alberta, have established their own remote-sensing centres, and Speciality centres exist at the Canada Centre for Inland Waters at Burlington for limnology, at the Department of the Environment, Ottawa for hydrology, at the Forest Management Institute, Ottawa for forestry, and at the Department of the Environment in Victoria, B.C. for oceanography.

The information content of satellite data is so high that it is not possible to display all the information in one colour print. Computer programs have been developed and special hardware systems are being acquired so as to make a statistical analysis of spectral signatures on the ERTS tapes.