详情

原文传递 SURFACE TRANSPORTATION AND GLOBAL POSITIONING SYSTEM IMPROVEMENTS: L5 AND DGPS.

题名：	SURFACE TRANSPORTATION AND GLOBAL POSITIONING SYSTEM IMPROVEMENTS: L5 AND DGPS.
作者：	Arnold-JA
关键词：	GLOBAL-POSITIONING-SYSTEMS; L5-DOWNLINK-FREQUENCY; DIGITAL-SYSTEMS; IMPROVEMENT-; TECHNOLOGICAL-INNOVATIONS; SELECTIVE-AVAILABILITY; SURFACE-TRANSPORTATION; POSITIONING-; ERRORS-; ACCURACY-
摘要：	Several proposed improvements to the Global Positioning System (GPS) are likely to benefit surface transportation. The two primary improvements are L5, the second civilian GPS downlink frequency, and Differential GPS (DGPS). This article dispels some of the myths surrounding these improvements and provides a clearer picture of their potential. In addition, the impact of setting Selective Availability (SA) to zero within the next 10 years is addressed from the perspective of its impact on both L5 and DGPS. L5 is planned to be an exact duplicate of the existing L1 downlink frequency. The contents of the navigation message include all the data necessary to determine a receiver's location. L5 provides redundancy and should fall within a band that has worldwide protection from interference. DGPS or augmented GPS describes several methods for improving the availability, integrity, and accuracy of the GPS service. The factors corrected include SA, atmospheric errors, and clock and ephemeris errors. L5 and DGPS provide different, but complementary, functions, all of which are important to surface transportation users.
总页数：	Public Roads. 1998/01. 61(4) pp2-7 (1 Phot., 1 Fig., 5 Tab., 4 Ref.)
报告类型：	科技报告