Ensimmäiselle sivulle GPS-route testing. Ensimmäiselle sivulle Introduction n Goal is to introduce...
-
Upload
theodore-bertram-greene -
Category
Documents
-
view
220 -
download
1
Transcript of Ensimmäiselle sivulle GPS-route testing. Ensimmäiselle sivulle Introduction n Goal is to introduce...
Ensimmäiselle sivulle
Introduction Goal is to introduce the results of
GPS-route accuracy tests Discuss about the problems
encountered while testing GPS-receivers
Ensimmäiselle sivulle
Contents What effects GPS-signal accuracy Tested GPS-receivers Test setting Encountered problems Test results
Ensimmäiselle sivulle
Uncontrollable variables Satellite coverage Weather Obstacles in route (roadworks,
traffic lights, etc.)
Although uncontrollable, these can be taken into account when planning testing
Ensimmäiselle sivulle
Controllable variables Devices Route Device position Location refresh rate (8s. intervals) Travelling method & speed
Ensimmäiselle sivulle
Test setting 8 tested devices
5 mobile phones using internal receiver
2 external Bluetooth receivers 1 wrist GPS
Clear weather
Ensimmäiselle sivulle
Possible problems Synchronizing Separating sequentially recorded
routes from each others Acquiring accurate reference route
& map anomalies Battery charge Data transfer (contracts & costs)
Ensimmäiselle sivulle
Measuring error to reference Different ways to calculate
distance between routes The DP-algorithm used:
for each actual point count distance to each of the remaining reference points pick smallest sum to optimal distance so far
Divide optimal sum with number of actual points within route
Ensimmäiselle sivulle
Problems with algorithm
Given results are better than what’s the actual error
This is due to comparing actual points to closest points in the reference route
Ensimmäiselle sivulle
Assumptions and results N95 slider-state might effect accuracy External receivers are expected to
produce better results Wrist GPS is expected to provide better
accuracy than integrated mobile phone receivers
Every device produced accuracy of less than 10 meters
Ensimmäiselle sivulle
Ranking of tested devices 6110 2.73m N95-2, open 3.13m N95-1 w/ external (Pretec) 3.61m Garmin wrist-GPS (1s.) 3.69m Garmin wrist-GPS (8s.) 3.75m E72 3.76m E66 5.10m N95-2, closed 6.05m N95-2 w/ external (Fortuna) 6.44m
Ensimmäiselle sivulle
Further improvements Implementing different kind of
measurement algorithm Creating better reference route