Which of the following can be considered a source of error in EDM (Electronic Distance Measurement)?

Atmospheric conditions are a significant source of error in Electronic Distance Measurement (EDM) systems. When measuring distance using EDM, accurate readings rely on the assumption that the velocity of the electromagnetic signal remains constant. However, variations in atmospheric conditions, such as temperature, humidity, and pressure, can affect the speed of the signal as it travels through the atmosphere. These changes can lead to inaccuracies in distance measurements because the propagation speed of the signal may be faster or slower than expected depending on these environmental factors.

Understanding the impact of atmospheric conditions is crucial for surveyors using EDM tools, as they must account for these variables to obtain precise measurements. Other sources of error, like uncertainty in calculations or battery life, may impact functionality but do not directly influence the measurement of distance in the same way that atmospheric conditions do. GPS signal accuracy pertains to positioning rather than direct distance measurement, which differentiates it from the EDM focus.