Known Issues

• Processing not robust to cases where targets defined in the *.tgts file are under the surface of the model grid

  • Some targets can have 3D locations that are defined such that they lie under the surface of the wind tunnel model grid. Thus, these targets will be rejected in phase 0 processing and will not be used as part of the registration process.

  • The current workaround is to perform preprocessing of the *.tgts file to ensure it is consistent with the model grid file (for instance, the locations can be offset in the direction of the nearest model grid surface normal by a small distance until they lie outside the grid surface)

• Image registration can cause poor performance when wind tunnel model has a significant amount of motion

  • The pixel-to-grid projection in Phase 0 is computed based on the first camera frames, and is then re-used for all camera frames; subsequent frames are “warped” to align with the first camera frame prior to projection, but tests for occlusion and obliqueness of model grid nodes are left unmodified

  • However, at the edges of the model visible to a given camera, when the model is moving significantly, parts of the model may move in- and out- of view of the camera

  • These model edges may then have degraded uPSP measurement accuracy when the model has lots of motion (e.g., at high Mach number).