AF/NGA GPS Monitor Station High-Performance Cesium Frequency Standard Stability 2005/2006: From NGA Kalman Filter Clock Estimates
Abstract
Both the National Geospatial-Intelligence Agency (NGA) and the United States Air Force (USAF/AF) operate a worldwide network of GPS monitoring stations that utilizes high-performance cesium frequency standards (CFSs) and geodetic quality GPS receivers. The USAF stations are somewhat equatorial, whereas the NGA stations are primarily in both the Northern and Southern Hemispheres. The NGA Monitor Station Network (MSN) has been in operation since 1983 and the operation in St. Louis currently monitors all the NGA stations on a 24/7 basis. The USAF operates their stations in a similar manner. The NGA monitor station CFSs are located in non-laboratory environments and in some instances, are logistically challenging. With the onset of the Department of Defense GPS Accuracy Improvement Initiative (AII), the NGA monitor station cesiums, along with the associative electronics, must be monitored more frequently for quality control. AII involves the USAF Operational Control Segment (OCS), at Schriever AFB, to incorporate at first a subset (six) of the NGA monitor stations in real-time processing to improve the quality of the broadcast ephemeris and clock parameters. Two more NGA monitor stations were added in the early fall 2006. The remaining three are scheduled to be added during the fall/winter 2006 time frame. The addition of the NGA stations will expand the network coverage to allow all GPS satellites to be monitored without any gaps.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2007
- Accession Number
- ADA474262
Entities
People
- Dennis M. Manning
Organizations
- National Geospatial-Intelligence Agency