The Surveyor's Calculator contains useful formulas for  height(h) by drop time calculating ranges (a) and elevations (Y) based on measurable observations (`theta_1, theta_2,` and x).  It provides a height estimate (h) base on time of a vertical drop, and it also provides a simple Interpolation (linear) calculation.

Recommendations

Additional formulas could be easily  Linear Interpolation  added to this calculator.  Please feel free to make suggestions by adding comments below.