The combination of the Vernier Video Physics and the Vernier Graphical Analysis apps works well to digitize and analyze simple video x,y coordinate data on the iPad. However, it is sometimes desirable to digitize more complex data (e.g., changes in the area of an object over time), and other apps work better in this regard. The guide below shows how to digitize a sequence of x,y video coordinates using Ubersense Coach and Labscope, both of which are free apps. The procedure can then be generalized to digitize perimeters, areas, or angles, and to calibrate measurements against a known standard.
A Guide to Digitizing Video Data with Ubersense and Labscope