Calculating Minimum Rotation Angle to Find Marked Geographical Locations Using Built-in Mobile Sensors

In this modern day, most areas in the world are covered with digital maps. Users can access maps online or offline by using electronic devices. When people travel to remote places, where there are no proper digital map coverage or a proper network connection, they often get lost. The aim of this research is to help travellers to keep track of their travel path when exploring uncharted territories while helping them to find previously marked locations with the help of built-in sensors in a mobile device. This paper proposes a new method of calculating the Minimum Rotation Angle (MRA) using the readings from a mobile device's accelerometer and magnetometer. MRA algorithm uses the data to calculate and predict the minimum angle that the user need to rotate the mobile device horizontally in order to find the previously marked locations. Different algorithms were used to calculate the rotation angle depending on the bearing value to the last marked location from the user's current location. Testing of the MRA was conducted in both urban and remote areas with different surrounding environments. Several low pass electronic filter methods were used to stabilize the mobile's sensor readings. It was found that Android Low pass filter had a high efficiency in stabilizing the sensor readings when it comes to calculating the MRA and it has a high effectiveness in reducing the noise of the sensor readings.