Starpath LOP Checker
Please Note: This online program works fine as long as your speed = 0.
We have determined there are errors if using it for running fixes. We are curenntly fixing this issue.

A key step in all of celestial navigation is the plotting of the LOPs we get from the sights.

We have practice with this in the course materials, but here is a way to check your work numerically.

It can be used for static sights or for moving sights as in a running fix or to correct sights taken during a single session.

You must be logged in with your WebCard to use this function, but you do not need to be enrolled in the Celestial Nav Course. Link to run it is below.


a-Lat = 51° N, a-Lon = 31° 12.0' W, a = 25.5' Toward Zn = 345°

a-Lat = 51° N, a-Lon = 30° 37.0' W, a = 25.0' Away from Zn = 033°

What is your position? Answer = 51° 14.2' N, 32° 24.6' W

For now we assume our speed is zero between sights, so we do not have to advance the lines to account for our motion. This program will also do the advancing. Instructions for that should be clear from the inputs, but we will add an example later on.


RUN LOP Plot Checker for S=0

Download a PC exe that works for running fixes as well: LOP_Checker.exe