Dissertation submitted in partial fulfilment of the requirements for the degree of Master of Science in Geospatial TechnologiesGPS has been a de-facto standard for outdoor positioning. For indoor positioning different
systems exist. But there is no general solution to fit all situations. A popular choice
among service provider is BLE-based IPS. BLE-has low cost, low power consumption,
and tit is are compatible with newer smartphones. These factors make it suitable for mass
market applications with an estimated market of 10 billion USD by 2020. Although, BLEbased
IPS have advantages over its counterparts, it has not solved the position accuracy
problem yet. More research is needed to meet the position accuracy required for indoor
LBS. In this thesis, two ways for accuracy improvement were tested i) a new algorithm for
BLE-based IPS was proposed and ii) fusion of BLE position estimates with IMU position
estimates was implemented. The first way exploits a concept from control survey called
well-conditioned triangle. Theoretically, a well-conditioned triangle is an equilateral triangle
but for in practice, triangles whose angles are greater than 30° and less than 120°
are considered well-conditioned. Triangles which do not satisfy well-condition are illconditioned.
An estimated position has the least error if the geometry from which it is estimated
satisfy well-condition. Ill-conditioned triangle should not be used for position estimation.
The proposed algorithm checked for well-condition among the closest detected
beacons and output estimates only when the beacons geometry satisfied well-condition.
The proposed algorithm was compared with weighted centroid (WC) algorithm. Proposed
algorithm did not improve on the accuracy but the variance in error was highly reduced.
The second way tested was fusion of BLE and IMU using Kálmán filter. Fusion generally
gives better results but a noteworthy result from fusion was that the position estimates
during turns were accurate. When used separately, both BLE and IMU estimates showed
errors in turns. Fusion with IMU improved the accuracy. More research is required to improve
accuracy of BLE-based IPS. Reproducibility self-assessment (https://osf.io/j97zp/):
2, 2, 2, 1, 2 (input data, prepossessing, methods, computational environment, results)
