Use this calculator to calculate and visualize what we can see of a target of a certain size and distance from any observer altitude, taking refraction into account. You can compare the results between flat earth and globe earth. Many more values are calculated and you can customize and store the settings.
Please read the paragraph on Refraction to get familiar with this panel.
Use this Formular to convert between different lengh units. You can Copy/Paste the results into input fields in the other Forms.
Note: Values marked with a * are not dependent on Refraction in reality. The marked values show the apparent values if refraction is not zero. So to display the real values, set Refraction = 0. This is true for all Horizon Data as well.
Angular Distance θ: is the angle between the observer, the center of the earth and the nearest target. This angle is used in some Drop calculators, as the Drop x is:
Note that \theta is the same angle as the Tilt of the target object.