openstb.simulator.travel_time.iterative

Travel time calculation plugins for the openSTB simulator.

Classes:

Name	Description
Iterative	Travel time including vehicle motion during the ping.

Iterative

Iterative(max_iterations, tolerance)

Bases: TravelTime

Travel time including vehicle motion during the ping.

This uses an iterative approach to find the travel time. The initial guess is found with the assumption that the vehicle motion at the start of the ping is constant throughout the ping. The receiver position at the proposed reception time is found. From the corresponding path length an updated travel time is found. This continues to iterate until successive travel times are within the requested tolerance.

This uses the sound speed at the position of the vehicle and time of the ping transmission throughout the calculation, and assumes that the sound travels in a straight line to and from the targets.

If a proposed reception time is after the end of the trajectory, an exception will be raised. Ensure that your ping time plugin is configured to leave a suitable gap between the final ping and the end of the trajectory for the echoes to return.

Parameters:

Name	Type	Description	Default
max_iterations	int	If a solution is not found within this many iterations, an exception will be raised.	required
tolerance	float	The tolerance in seconds. If the travel time estimated in successive iterations differ by less than this, they are considered successful.	required

Source code in openstb/simulator/travel_time/iterative.py

def __init__(self, max_iterations: int, tolerance: float):
    """
    Parameters
    ----------
    max_iterations : int
        If a solution is not found within this many iterations, an exception will be
        raised.
    tolerance : float
        The tolerance in seconds. If the travel time estimated in successive
        iterations differ by less than this, they are considered successful.

    """
    self.max_iterations = max_iterations
    self.tolerance = tolerance