China Wants Its Own GPS
China is expected to launch two satellites next year that will start its GPS constellation. The Beidou (Compass) satellites will provide coverage for most of China and some neighboring countries before the country launches the remaining 33 satellites to yield worldwide coverage. The plan was confirmed by state-controlled news services last week. The open frequency from the system will give navigational accuracy to 10 meters, with speed accuracy to within 0.2 meters per second and timing accuracy to within 50 nanoseconds. The "authorized" service will be better on all three counts. The news services said China isn't necessarily going to keep the system to itself and is willing to cooperate with other countries to make it compatible. There are three GPS systems in operation. The U.S. Air Force's system was operational in 1978, the Russians built theirs in the 1980s and the European Galileo system was begun in 2002. China's system will ultimately include five geostationary satellites and 30 medium orbit satellites.