To determine the y-position of the metal sheet in the ultrasonic seam bond sensor (see Fig. 1), the elapsed time of the echoes from the water to steel transition of the two arrays A and B can be evaluated by using a defined time gate.
Therefore, the joint-data imaging approach allowed better retention of noise and resolution properties of the EP and quasi-CW images than could be obtained by simply choosing a later time gate.
Both propagation mechanisms can be efficiently separated by applying a rectangular time gating at 7 ns.
By the time Gates was a teen-ager, gangs and crack ruled, and the city addressed the problem by bulldozing historic buildings that were being used as drug dens.
To some degree an effect similar to the HDS image reconstruction approach— i.e. trading off resolution and noise can also be obtained with a time-gated imaging system simply by choosing a later measurement time gate, since later time gates yield worse resolution but better signal to noise performance.
By that time, Gates was writing personal notes at the bottom of every condolence letter sent to families of troops killed in battle.
We apply this new model to the simultaneous reconstruction of two fluorophores with lifetime contrast.We investigate for this purpose the information content imparted by single time gates and perform optical reconstructions based on multiple time gates to simultaneously image two fluorophores.
In our simulations the Raman signal has been excluded in order that we can concentrate on the more difficult problem of identifying signal in the presence of a uniform background signal, which will always be the fundamental noise floor in any experiment, however carefully designed, and after temporal filtering by time gating has been applied.
In addition to the IrIII-based imaging, the long-lived sensitised Eu-based luminescence from 1⋅Eu, following two-photon excitation of the Ir chromophore at 780 nm, also permitted images to be obtained by time gating the detection to reject the (relatively) short-lived Ir component.
In practice our approach is close to the 'causality corrected' TDDA approach suggested by Feld et al. [ 16], wherein TDDA was used but the detection time gate was shifted by the un-scattered photon transit time through the media.
