Sect_12.3.2

TRENDS IN GPS INSTITUTIONAL ISSUES

Increasing "tug-a-war" between civilian and military users --> will the U.S. military abandon GPS in favour of a new military-only system?
Transmission of a new "military-only" signal on the Block IIF satellites
Abandon "Selective Availability" in the next few years --> reduce the need for GPS base stations for transmitting DGPS corrections.
Bypass "Anti-Spoofing" through transmission of additional (civilian) frequency on Block IIF GPS satellites --> make "on-the-fly" ambiguity resolution more certain.
Integration of GLONASS satellites to improve availability and reliability for critical navigation users --> but there remain many uncertainties concerning the commitment of the Russian Federation to GLONASS.
Increased concern about GPS control, and plans revealed by the European Union to develop a civilian-only Global Navigation Satellite System (GNSS2) --> but will "Galileo" truly be without military involvement?

More countries will redefine their national geodetic datums to be coincident (at some level of accuracy) with the ITRS --> a geocentric datum.
Convergence of definition of WGS84 with ITRFxx reference frames --> already happening.
GPS is unchallenged as the geodetic tool for establishing, maintaining or renovating national control networks.
In addition to the traditional levels of national control network (first order/class, second order/class, etc.), there will additional high accuracy control points established using "GPS geodesy" techniques --> these will be the "backbones" of new datums.
With the increased efficiency of GPS for establishing control point coordinates, there will be a trend to reduce the number of physical control marks --> easier to establish marks when and where they are needed.
Where permanent control marks are established, they will be increasingly located where they are most needed, not on inaccessible hilltops --> intervisibility of stations not necessary for GPS, but some is necessary to define azimuth to support conventional ground survey techniques.
A range of GPS hardware can be used, and the RINEX data reduced using a preferred software package --> including the "GPS geodesy" software.
Real-time operation of GPS base stations will permit real-time GPS control surveys.

Increased blurring of role of GPS infrastructure --> e.g. permanent GPS control marks will also support real-time DGPS, Integrity Monitoring, etc.
Increased acceptance of the IGS service --> precise orbit information and access to the International Terrestrial Reference Frame.
Expanding network of permanently operating GPS receivers tied to the ITRS --> continuous "active" control station connection to ITRFxx.
Issues such as GPS system testing, accreditation of GPS surveyors, procedures for GPS cadastral surveys, legal traceability of GPS results, etc., will become increasingly important.
GPS positioning will not only be the prerogative of the "positioning professions" such as Navigation and Surveying.
Development of multiple reference station techniques to support GPS surveying and precise GPS navigation.
Expansion of "wide-area" pseudo-range-based DGPS to include carrier phase techniques.
Increasing "internationalisation" of GPS --> leading to more integration of GPS datums such as has occurred in the case of Australia and New Zealand.