Can GPS devices substitute for altimeters in navigation?

GPS Limitations in Elevation Measurement

GPS devices can estimate elevation based on signal delay, but this method is prone to error and inaccuracy. At high elevations, signal delay may lead to significant errors in elevation measurement. In environments with GPS signal blocking, such as dense forests or urban canyons, elevation data may not be available or may be highly unreliable. Typically, GPS devices have an elevation accuracy of around 10-20 meters, which can be significant in terrain navigation.

Altimeter Advantages

Altimeters, on the other hand, provide a direct and precise measurement of elevation, typically with an accuracy of 1-5 meters. This makes altimeters an essential tool for navigation in mountainous terrain, where accurate elevation data is crucial for safe and efficient travel. Altimeters can also provide continuous elevation data, even in GPS signal-blocking environments, making them a more reliable choice for navigation.

Practical Considerations

In practice, GPS devices and altimeters can be used together to provide a more accurate picture of elevation. By cross-checking GPS elevation data with altimeter readings, navigators can gain a more reliable understanding of their surroundings and make more informed decisions about route selection and terrain navigation. However, in areas with reliable GPS signal reception, a GPS device with built-in elevation estimation may be sufficient for casual navigation.