Deliberate interference of positioning signals has increased during the past few years all over the world. Even in nominal conditions satellite signals are not available everywhere. Still, for the sake of security, personnel in tactical or rescue operations need to be located even when satellite-based positioning is not usable.
Localization based on inertial and other carry-on sensors provides a solution in these situations, but the positioning accuracy degrades over time. Cooperative positioning methods, that utilize distance measurements between the members of the navigating team, enable accurate positioning for longer periods of time.
Even a small team benefits from cooperation
In cooperative positioning the members of the team are almost like local navigation satellites to one another. Location uncertainty is higher compared to satellite-based positioning, which requires careful handling in the algorithm estimating locations. The navigating group does not need to be large in order to take advantage of cooperative methods.
“The results show that already for a team of two the positioning accuracy may be improved by incorporating distance measurements into the sensor fusion,” Maija Mäkelä says.
Cooperative methods are applicable also for different vehicles
In the dissertation the cooperative positioning methods are applied for pedestrian localization, but the methods are suitable also in a broader context.
“The methods developed in the dissertation are applicable almost as such also for localization of cars or aerial vehicles, for example. In addition, the method for correcting bias in distance measurements presented in in the dissertation is suitable also for traditional indoor positioning,” states Mäkelä.
The research for the dissertation has been conducted at the Finnish Geospatial Research Institute (FGI) at the National Land Survey. Maija Mäkelä, originally from Ilmajoki, Finland, works in Espoo as an Algorithm Engineer with Nordic Inertial Oy and as a part-time Research Scientist at the Department of Navigation and Positioning at FGI.
Public defence on Friday 19 September
The doctoral dissertation of M.Sc. (Tech.) Maija Mäkelä in the field of communications engineering titled Cooperative Methods and Algorithms for Infrastructure-free Positioning will be publicly examined at the Faculty of Information Technology and Communication Sciences at Tampere University at 12 o’clock on Friday 19.9.2025 at Hervanta campus at the Rakennustalo, auditorium RG202 (Korkeakoulunkatu 5, Tampere). The Opponent will be professor Jesus Ureña from the University of Alcala, Spain. The Custos will be professor Jari Nurmi from the Faculty of Information Technology and Communication Sciences.
The doctoral dissertation is available online.
The public defence can be followed via remote connection.