My research at UNB has been directed towards investigating algorithms required to model the GPS signal delay due to the neutral-atmoshere (usually referred to as the "troposheric delay").  These algorithms are required specifically for receivers on-board user platforms (that is, aircraft) flying in the US FAA's Wide Area Augmentation System.  This system will provide the necessary safety back-up to enable GPS to be used as a precision navigation aid for civilian aviation across North America.

A comprehensive list of papers in pdf format is available from Professor Richard Langley's web page.

The following papers can be obtained in postscript format:

Mendes, V.B., J.P. Collins, and R.B. Langley (1995). "The Effect of Tropospheric Propagation Delay Errors in Airborne GPS Precision Positioning." Proceedings of ION GPS-95, the 8th International Technical Meeting of the Satellite Division of The Institute of Navigation, Palm Springs, CA, U.S.A., 12-15 September 1995; pp. 1681-1689.

Collins, J.P. and R.B. Langley (1996). "Mitigating Tropospheric Propagation Delay Errors in Precise Airborne GPS Navigation." Proceedings of PLANS '96, the 1996 IEEE Position, Location and Navigation Symposium, Atlanta, GA, U.S.A., 22-26 April, 1996; pp. 582-589.

Collins, P., R. Langley, and J. LaMance (1996). "Limiting Factors in Tropospheric Propagation Delay Error Modelling for GPS Airborne Navigation." Proceedings of The Institute of Navigation 52nd Annual Meeting, Cambridge, MA, U.S.A., 19-21 June 1996; pp. 519-528.

Collins, J.P. and R.B. Langley (1997). (Invited) "Estimating the Residual Tropospheric Delay for Airborne Differential GPS Positioning (A Summary)." Proceedings of the 1997 Scientific Assembly of the International Association of Geodesy, Rio de Janeiro, Brazil, 3-9 September (in press).

Collins, J.P. and R.B. Langley (1997). " Estimating the Residual Tropospheric Delay for Airborne Differential GPS Positioning." Proceedings of ION GPS-97, the 10th International Technical Meeting of the Satellite Division of The Institute of Navigation, Kansas City, MO, U.S.A., 16-19 September 1997; pp. 1197-1206.

Collins, J.P. and R.B. Langley (1998). "The Residual Tropospheric Propagation Delay: How Bad Can It Get?" Proceedings of ION GPS-98, the 11th International Technical Meeting of the Satellite Division of The Institute of Navigation, Nashville, TN, U.S.A., 15-18 September 1998; in press.