StudioView Trajectory Converter (see Converting a Trajectory in StudioView) has several adjustable parameters that can be used to enhance a trajectory, thus making it more suitable for simulation.
In StudioView, open the Trajectory Converter tool by clicking the icon, or navigate to Tools > Trajectory converter:
Apply changes to the original trajectory as needed, following the tabs from left to right. The diagram below illustrates some of the parameters.
Downsampling means decreasing the number of points in a trajectory, so as to make those parts of a trajectory with constant movement parameters as long as possible. The downsampling algorithm excludes points which are within a specified deviation from the general movement direction. If your trajectory uses a substantial number of points, it is strongly recommended to apply downsampling.
Enable it by checking the box on Downsampling tab. To define a deviation, select an Inaccuracy estimation type, and enter a max. value for it. Also enter a maximum speed change for the trajectory segment.
Smoothing is used to adjust movements parameters that are critical for the receiver performance. By changing the smoothing parameters, you can achieve more realistic speed changes and turn abrupt heading changes into more realistic gradual turns. Enable it by checking the box on the Smoothing tab. The smoothing algorithm will add points to the trajectory as determined by the algorithmn.
- The Max rounded distance is measured from a particular rounded point.
- The Max rounded segment percent represents the value of the maximum rounded distance in % from the rounded point relative to the length of entire trajectory segment. The segment of the trajectory refers to any part of a trajectory between two consecutive points.
- The Max angular velocity defines the speed of a turn. While rounding angels of trajectory, resulted angular speed will be interpolated within specified limit.
- The Max vertical velocity defines the maximum permitted vertical movement between consecutive points. If the altitude has changed between two consecutive points, it will be interpolated, applying this not-to-exceed vertical velocity.
- The Heading change threshold defines the maximum change of movement direction at any particular point. If the actual value is greater than the heading change threshold, the trajectory will be rounded at this point.
- The Max acceleration in m/s². (3.8 m/s² is a typical value for a performance car [0-60 mph in 7s]).
Interpolation allows to add points to the original trajectory. Enable it by checking the box on the Interpolation tab.
An Interpolation step value of 1 per second generates 1Hz data.
Note: The maximum number of points for an NMEA trajectory is 12000!
Use equalization if a steady speed or constant altitude is needed. The value entered will be applied to all waypoints of the trajectory.
The NMEA tab allows to set up a Stationary period in seconds. It will be added to the beginning of trajectory, allowing the receiver to obtain a fix before any movement starts (this will help to avoid that the receiver under test possibly does not capture the initial part of the trajectory).
Note: This feature only works if the file type of both the Input, and Output trajectory is NMEA, and if the Output destination is set to Write to file.