Best practices for handling lost signal when using GPS?

Understanding Dead Reckoning

Dead reckoning is a navigation technique that estimates your current position based on your previous known position, speed, and direction of travel. To implement dead reckoning, calculate your pace count, which is the number of steps taken per unit of time, typically 100 meters. For example, if you know you walk 100 meters in 10 minutes and you’ve been walking for 20 minutes, you can estimate that you’ve traveled 200 meters.

Implementing Dead Reckoning

Using your pace count, estimate your current position by adding the distance traveled since your last known position. For example, if your pace count is 100 meters per 10 minutes and you’ve walked for 20 minutes, you’ve traveled 200 meters since your last known position. To adjust for wind, currents, or other factors that may affect your speed, use the ‘fudge factor’ technique. This involves increasing or decreasing your estimated speed by a small percentage, typically 5-10%, to account for these variables.

Using Your Surroundings for Navigation

When a GPS signal is lost, it’s essential to use your surroundings to aid in navigation. Look for visual landmarks, such as mountains, rivers, or buildings, to help you estimate your direction of travel. Use your altimeter to estimate your elevation and adjust your dead reckoning calculations accordingly. Additionally, use your compass to take bearings on nearby landmarks and estimate your position relative to them. By combining these techniques, you can accurately estimate your position and navigate to your destination.