You will see that the red frame on the right hand side is equal to the red rectangle on the left hand side.The black rectangle is the latitude. Longitude that pass the calculation comes from the red frame.
You can see the red box on the right is the equivalent of the Red left the black frame is the latitude. Longitude recent calculations by the red frame.
Can be seen that the round red on the right hand side is equal to the red frame left black frame is the latitude. Through the calculation of longitude from the red frame .