GPS Civil Monitoring Performance Specification

PDFTech ReportGlobal Positioning SystemUnited StatesUnited States. Dept. of TransportationUS Transportation CollectionThis Civil Monitoring Performance Specification (CMPS) is published and maintained atthe direction of the Program Manager for Civil Applications, Global Positioning SystemsWing (GPSW). The purpose of this document is to provide a comprehensive compilationof requirements for monitoring the GPS civil service and signals based on top levelrequirements to monitor all signals all the time. Upon approval this CMPS will be usedby the GPS community to determine the adequacy of civil monitoring and provide focusfor any needed monitoring improvements.This CMPS defines a set of metrics for assessing GPS performance against standards andcommitments defined in official U.S. Government documents such as the StandardPositioning Service Performance Standard, the Navstar GPS Space Segment/NavigationUser Interfaces (IS-GPS-200), Navstar GPS Space Segment/User Segment L5 Interfaces(IS-GPS-705), and Navstar GPS Space Segment/User Segment L1C Interfaces (IS-GPS-800). This CMPS will be revised to track changes in these key reference documents.The implementation of a system that satisfies these requirements will allow operations aswell as users to verify that civil GPS performance standards and commitments areachieved. To the extent practicable, each metric defined is traceable to one or morespecifications or commitments of performance. In cases where the metric is an indirectmeasurement of performance, the connection between the metric and the standard isexplained and the threshold and/or goal necessary to achieve acceptable performanceprovided.This document also defines the scope and range of monitoring needs not directlytraceable to the key reference documents but expected by civil users. These needsinclude the ability of the service to detect defects in signal and data, the rapid report ofanomalous service behavior to satellite operations for resolution, and notification to usersof the causes and effects of such anomalies for their various service types (e.g.,positioning, timing, and navigation). This CMPS also addresses the need for archives ofkey data and events to support future improvements in GPS service and to respond toexternal queries about actual GPS service levels.This CMPS addresses the current L1 C/A signal and the GPS Standard PositioningService (SPS) provided via that signal. It also includes the planned L1C, L2C, and L5signals along with semi-codeless use of the GPS signals.This performance specification is not intended to state how civil monitoring will beimplemented nor does it address the monitoring system architecture. The purpose of thisCMPS is to provide the current requirements for monitoring of the civil service andsignals for use by the U.S. Government in planning GPS development efforts. As aresult, many of the requirements contained in this CMPS may be incorporated into thenext generation operational control system (OCX), while other requirements may beallocated to other government entities for implementation