Popis: |
Many polar nations, including Canada, the United States, Russia, and the Baltic countries, support shipping and other maritime activities in ice-encumbered waters. Visual reconnaissance from aircraft was initially used to map sea ice distribution but this method suffered from extremely limited range and subjective interpretation techniques. Imaging radar became available in the early 1970s when real aperture side-looking airborne radars (SLAR) were deployed to complement and extend the range of traditional visual observations. Canada was the first nation to routinely deploy synthetic aperture radar (SAR) for operational ice surveillance when it commissioned an X-Band SAR on a high-flying jet aircraft. The European Space Agency’s ERS-i was the first satellite to provide SAR data on a sufficiently regular basis for operational ice surveillance. Canada’s RADARSAT was specifically designed with operational ice surveillance as one of its major objectives. |