A-GPS Tracker 5.5

This app is an outdoor tracker that utilizes the A-GPS capabilities of your phone. When activated, it can record your track even when the phone is in standby mode. It is specifically designed for hikers who want to record a new path or follow an existing track, and most importantly, want to avoid getting lost on their return journey.

Features:

• Elevation is provided relative to mean sea level (note that most Android programs do not offer this).
• Latitude and Longitude coordinates are given in degrees and in UTM-WSG84 (published in paper maps).
• A track is stored in a GPX file and can be recorded, stored, loaded, and shared with others. The elevation versus distance profile can be displayed on the screen.
• Statistics of a loaded GPX track include net walk time, ascent, and descent altitude.
• A "follow path" monitor function can be enabled to provide an alarm if you deviate from a loaded GPX path.

It is important to note that while this app is effective for tracing your path, its accuracy for measuring walked distance is not as reliable. The distance is measured as the sum of distances between points acquired every 3 seconds or 5 meters, but GPS accuracy is typically around 10-20 meters. If the path is not straightforward (like a car following a road), the final result may not be very accurate. Errors of up to 15% in distance measurement are normal.

These errors are influenced by several factors, with the most important being the quality of received satellite signals (poor when the sky is cloudy), changing configuration/relative position of satellites, and reflections of signals on large surfaces like walls and buildings. This is why GPS position coordinates may be less accurate when signals are weakened by weather conditions or in urban areas with multi-path propagation due to reflections on buildings.

GPS is used here as a generic term referring to the capability of receiving position data from satellite signals. Modern phones can obtain position data from multiple satellite systems, such as GPS, GLONASS, BeiDou, and Galileo. The A-GPS Tracker app will receive data from all available satellite navigation systems. Additionally, A-GPS (Assisted GPS) utilizes ground sources like cell tower data and WiFi to enhance quality and precision in poor satellite signal conditions, ultimately reducing the time it takes to initially fix your position. GPS remains the most accurate source of position data, including latitude, longitude, and altitude, which is particularly important for hikers.