Sea ice and meteorological information has been gathered and analyzed from a broad range of source data. Surface-based observation data are gathered from icebreakers and other vessels traversing the NSR as well as from land-based and drifting autonomous observation stations throughout the Arctic Ocean. The data from these autonomous stations are sent to CIHMI through the OKEAN satellites. Aerial and space observations consist of remote sensing data from satellites and reconnaissance by airplanes. Satellite data is gathered not only by Russia's OKEAN
*A new commercial system called IRIDIUM, developed by Motorola, can offer telephone communication to any point on Earth. A constellation of 66 polar-orbiting satellites in a low 760km orbit altitude can provide voice communication anywhere, but not data transfer.
and METEOR satellites but by NOAA satellites as well, relaying images to land-based stations in the visible-light, infrared and microwave ranges. Visual observations are gleaned from aircraft as well as through monitoring by side-looking radar.
Needless to say, Russia's automated ice/hydrometeorological information-gathering system did not appear overnight. The quality and quantity of the observation data they gathered increased over time in tandem with technological progress. Regular observations from aircraft began in 1941-1942. Although originally only visual observations were conducted, after the introduction of side-looking radar in 1968 it became possible to perform year-round base observations. The era of satellite data began in 1969 with the reception of visual-light range images from the Meteor-1 satellite series. In 1975 the Soviets launched the Meteor-2 satellite series which carried sensing systems for infrared range in addition to visual-light range. The successor to these satellites, the Meteor-3 series, was launched in 1987 and is still in use today, and in 1983 the OKEAN-1 series was launched, loaded with side-looking radar, microwave radiometer and visible-light sensors.
As this monitoring technology, particularly satellite monitoring, advanced in sophistication, the systems used to gather and deliver data on ice and sea conditions in the NSR evolved with it. Before remote-sensing data from satellites came into extensive use, information was gathered and analyzed at regional centers in Dikson, Pevek and other northern port cities. Each of these centers used the data to provide short-term (about one week) forecasts of ice and weather conditions, provide ship traffic control stations with ice maps and to provide advice to crews navigating the NSR. The information from each center was sent to CIHMI, where the data was tabulated to produce ice maps for the entire NSR and medium-to-long-term forecasts (from two or three months to a year) of ice and weather conditions, which it then forwarded to ship traffic control stations. As both the quality and quantity of the data gleaned from satellites improved, however, the limitations of the regional centers in processing this satellite data became apparent, and the case for maintaining these regional centers weakened. Presently sea ice and meteorological data are handled centrally at CIHMI, which prepares short-term ice forecasts and ice maps and provides a variety of information to ship traffic control stations and other users of the data.
(5) Technology for satellite monitoring of sea ice conditions
Information on sea ice conditions is essential for NSR navigation and northern navigation in general. Unfortunately the number of observation stations and aircraft, ships and so forth used for observation is limited. Moreover the brutal natural conditions make local observation and measurement difficult in many cases. Recently, however, significant progress has been made in technologies for the observation of the earth's surface, enabling satellite imaging to be applied to monitoring of ice conditions. As stated earlier, the monitoring of sea ice conditions through satellite images is one of the key tools used for ice-condition forecasting in the NSR.
