Often these different measurements that are taken at multiple sensitivity levels are combined computationally, and in this sense, HDR is known as "Being Undigital", i.e. using digital signal processing to achieve an "undigital" (continuous, non-quantized) result [link].
HDR was originally envisioned as a realtime seeing aid to help people see and understand their world better [ask your TA for a copy of the realtime HDR video article and the cyborg-HDR history chapter if you are interested in learning more].
HDR is related to the previously known and used method called "signal averaging", but instead of measuring the same thing over and over again at the same gain setting, HDR involves measuring the same thing over and over again at different gain settings.
In this lab you will build an HDR sonar system that uses the phenomena of HDR sensing.
Construct a means for moving the apparatus towards and away from a wall or
other object, where the apparatus moves along the same path, as shown in
the diagram below:
I've shown a toy car that would ride in a track or slot or groove to keep it riding along the same path, but you're free to use your imagination and build any kind of apparatus, e.g. a rail car, or railway guide, or sliding mechanism, or the like, as long as it adheres to the scientific principle of reproducible results.
You may work in pairs on the construction and collection of the data, but each person must do their own data analysis.
Devise a way to collect data for each of the three different exposures, i.e. weak, medium, and strong, for each of a variety of distances from the wall or other subject matter.
Collection of data from the apparatus, for each of the three exposures (weak, medium, and strong), as a function of distance from the wall or other object, showing an example of a wave that exhibits clipping and cutoff (i.e. too strong and too weak), with good choice of samping interval (at least satisfy the Nyquist sampling criteron, and preferably well beyond that), and good range (good dynamic range), 4/10
Plotting a graph of the three separate exposures, aligned on top of each other, in a single plot, 2/10.
Bonus mark if you can supply three good quality photographs of wave for each of the three separate sensitivities.