GSI V-Stars Photogrammetry Simulation

The V-Stars simulation utility provides the user with the ability to lay out a network of cameras and points, establish which of the points are within the camera’s field of view, bundle the cameras together and determine the network uncertainty for each point. This a very powerful tool for pre-designing a measurement process.

 

Requirements

 

Simulation Overview

The simulation process is conducted from the properties of the V- Stars instrument added to the SA tree. The basic concept is that a set of camera positions can be established in SA, and a set of reference points defined. Along with these you can establish a set of reference vectors relative to the surfaces and objects that are being measured.

You can then fabricate measurements to these points and take ad- vantage of the position and orientation of the surface to determine which points are visible and fabricate measurements to those.

Once the fabrication process is complete a V-Stars bundle can be run and the resulting uncertainty for each point established.

 

Simulation Setup and Controls

To begin, setup your camera network for the simulation process. This includes both the camera parameters and locations.

  1. Set the Camera Parameters to match those of your camera and the incident angle threshold.

    The Camera Parameters dialog allows the user to establish the field of view of each camera, which establishes the points/vectors visible. This field of view is established using the parameters of the camera to be used. The size of the CCD and the focal length of the lens establish the angle of visible area while the range parameters establish the distance parameters in clear focus or within range. The Incident Angle is used only with vectors and further limits the number of points considered. If the incident angle is larger than the tolerance you set it will be excluded from the calculation.

 

  1. Establish and editing the Camera Network Configuration

    The Camera Network button provides full control over the cameras within a V-Stars network and their display within SA. Remember that a single instrument added to the SA tree represents a network of cam- era locations and each camera location relative to the network frame is controlled from this dialog. Here you can add or import cameras to the network, edit there position and orientation and change their display attributes.

  2. This dialog can be used before, during and after shots are fabricated and the bundle is run. It is a very useful tool for analysis in that it allows individual shots from particular cameras to be turned on or off and the field of view analyzed. Parameters of a particular camera can be accessed by right-clicking on the camera in the network list and multi-camera control is provided through the buttons in the right panel.