The approach outlined in this paper conservatively bounds the ionospheric errors even for the worst observed ionospheric conditions to date, using data sets taken from the operational receivers in the WAAS reference station network.

Wide Area Augmentation System (WAAS) ionosphere ir↗

NASA NTRS2000

Reducing Systematic Bias Variation in Global Ionosphere Maps to Support Satellite Altimeter Calibration

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ionosphere altimeter calibration TOPEX↗

NASA NTRS2000

Ionospheric specification algorithms for precise GPS-based aircraft navigation

We present a technique for converting real-time total electron content (TEC) measurements into gridded vertical delay corrections at the GPS L***sub***1 frequency, which will be broadcast to users every 5 min via geosynchronous satellite. Users will convert these delays to slant corrections for their own particular lines of sight to GPS satellites. To preserve user safety, estimates of the error in the user delay corrections will also be broadcast.

Global↗

NASA NTRS2000

Cosmic GPS ionospheric sensing and space weather

As our civilization becomes more dependent on space based technologies, we become more vulnerable to conditions in space weather. Accurate space weather specification and forecasting require proper modeling which account for the coupling between the sun, the magnetosphere, the thermosphere, the ionosphere and the mesosphere.

GPS↗

NASA NTRS2000

Global Mapping of the Ionosphere Using GPS

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Ionospheric Modeling irregularities↗

NASA NTRS2000

A New Model for Retrieving Slant TEC Corrections for Wide Area Differential GPS

To provide delay corrections to single frequency users, wide area differential GPS systems depend upon accurate determination of ionospheric total electron content (TEC).

Retrieving↗

NASA NTRS1999

Ionosphere Delay Calibration and Calibration Errors for Satellite Navigation of Aircraft

The Federal Aviation Administration (FAA) is implementing a satellite-based navigation system for aircraft using the Global Positioning System (GPS).

satellite-based↗

NASA NTRS1999

Assessment of Global TEC Mapping Using a Three-Dimensional Electron Density Model

Dual-frequency transmissions from the Global Positioning System satellites can be used to measure and map ionospheric total electron content (TEC) on global scales. Using data exclusively from ground-based GPS networks, global ionosphere mapping has been successfully applied using either two or three dimensional techniques.

Global↗

NASA NTRS1999

Capabilities and Limitations of Radio Occultation

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Ionospheric Tomography profiling and data assimila↗

NASA NTRS1999

Automated Daily Process for Global Ionospheric Total Electron Content Maps and Satellite Ocean Altimeter Ionospheric Calibration Based on Global Positioning System Data

The accuracy of single-frequency ocean altimeters benefits from calibration of the total electron content (TEC) of the ionosphere below the satellite.

ionosphere ocean altimetry global positioning syst↗

NASA NTRS1999

Capabilities and Limitations of Radio Occultation Measurements for Ionosphere Monitoring

The paper: (1) describes the range of capabilities of GPS radio occultation missions in ionospheric research: (a) ionospheric profiling; (b) ionospheric imaging; (c) ionospheric data assimilation; and (d) measurement of scintillation. (2) Identify strengths and weaknesses of measurements: (a) coverage; (b) resolution; and (c) uniqueness of solution.

Hajj, G. A.↗

NASA NTRS1999

Determining The Uncertainty of Ionospheric Corrections For Users In Wide Area Augmentation Systems

Broadcast messages of the FAA's Wide Area Augmentation System (WAAS) include the grid ionosphere vertical error (GIVE).

GPS↗