An Efficient Algorithm Based on Kalman Filters to Improve Positional Accuracies of GPS Reciever Divy Jain Veermata Jijabai Technological Institute,Mumbai, India Email: divjain@deloitte.com Anil A. Kulkarni Officer Grade SO-SS SAMEER(Society for Applied Microwave and Electronics Engineering and Research) ,Mumbai Email: anilk@sameer.com Dr. Sangeeta Vaidya Asst. Professor Directorate of Technical Education,Mumbai Email: vaidya@dte.org.in Dr. B.K Lande Professor VJTI,Mumbai Email: bklande@hotmail.com Abstract: The Global positioning System (GPS) allows properly equipped users to determine their positions based on the measured pseudo ranges from at least four satellites. GPS is increasingly finding application in the fields of meteorology, navigation and geodesy. An application of GPS in meteorology is to determine the upper air wind profiles. A GPS receiver is capable of transmitting its position as latitude, longitude & altitude. These positional measurements however suffer from various errors & if used directly for wind profile determination will lead to erroneous estimations. The conventional method of using Differential GPS (DGPS), to improve the position accuracies is very complex for implementation and requires raw data that all GPS receivers cannot transmit. In these paper two different navigational algorithms based on Kalman filters is discussed. Experimental work to evaluate the performance of these algorithms was carried at Civil engineering department at IITB, Mumbai. The algorithms performance is evaluated by keeping distance as parameter. These algorithms are simulated in Matlab version 6.0.