ABSTRACT
A pulsed ruby laser holographic interferometer was used to detect density gradients in the airflow around an airfoil at subsonic speeds in a low speed wind tunnel. These experiments proved that vibration of the optical components or object between exposures of the interferometric hologram does not destroy the detection of density gradients but actually can aid in the flow visualization. The density gradients determined from the fringe pattern analysis are consistent with the anticipated flow pattern.
ABSTRACT
The effect that any parameter of a holographic or coherent imaging system would have on the resultant image is normally described by an amplitude modulation transfer function. We show here that an intensity modulation transfer function (MTF) can be used to analyze the coherent systems if diffuse targets are employed and if the usable area image.
