1. Hofmann-Wellenhof B, Lichtenegger H, Wasle E. GNSS-Global Navigation Satellite Systems: GPS, GLONASS, Galileo & More (in Chinese). Beijing: Surveying and Mapping Press, 2009
2. Chen Z G, Shuai P, Qu G J. Analysis of the technical character and develop tendency of modern satellite navigation system (in Chinese). Sci China Ser E Tech Sci, 2009, 39: 686–695
3. Chen J Y. On progress in technology and modernization of GPS (in Chinese). J Geod Geodyn, 2010, 30:1–4
4. Yang Y X. Progress, contribution and challenges of Compass/Beidu satellite navigation system (in Chinese). Acta Geod Cartogr Sci, 2010, 39: 1–6
5. Milbert D. Improving dilution of precision, a companion measure of systematic effects. GPS World, 2009, 20: 38–47