However, if you’re trying to measure absolute altitude, things become a bit more complicated because the BME280 needs to know the current sea level pressure. For example, if you know the altitude of an object sitting on a table and you move it to the floor, the BME280 will show a 2 foot decrease in height. Because the BME280 is very good at measuring pressure, it can calculate relative altitude accurately. Note that the BME280 cannot directly measure altitude but can estimate it using pressure readings.
The term “absolute altitude” refers to the height above sea level (MSL), whereas “relative altitude” refers to the height above ground level (AGL). The BME280 can measure pressure with such precision (low altitude noise of 0.25m) that it can also be used as an altimeter with an accuracy of ☑ meter.īefore proceeding, it is important to understand the distinction between Absolute and Relative Altitude.
