Performed noise floor tests on inertial referencing circuit. To do this I shorted the displacement input to ground, then took the PSD of the displacement-velocity. I did the same to the accelerometer input and acceleration-velocity.
Once I had the noisefloors of the circuit and the sensors, I overlayed them on a plot. I had a difficult time understanding what calibration factor to apply to the circuit noise floors to get them into in/s. In the end the confusion came from two things. One, I was overcomplicating things…the output of each part of the circuit is in Volts. It doesn’t matter what happened to that voltage along the way, volts are volts. This new voltage was simply proportional to velocity instead of disp/acceleration now. The second thing that was confusing was the gain to apply. I thought it would have more to do with the cal factors of the sensors, but that is not so. I talked this over with Brad and the actual circuitry itself has a gain of 2 (in/s)/V for both accel velocity and disp velocity. I had no way of knowing this beforehand, which was slightly frustrating.
During this day I also edited the read_ati_file.m and read_afu_file.m. Before now, they did not have a field which contained a description of each channel, or have a field which specified the units. I used V=get(*ideas_fn file) to get a list of all the possible fields which can be written to the .mat file. I could not find one for units, so I just had the read files record what units you told it to export in.
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