Usual Waveform Research Articles

Gravitational wave interference via gravitational lensing: Measurements of luminosity distance, lens mass, and cosmological parameters

The gravitational lensing of gravitational waves might cause beat patterns detectable by interferometers. The feature of this kind of signal is the existence of the beat pattern in the early inspiral phase, followed by a seemingly randomly changing profile. After the strain peaks for the first time, the signal takes the usual waveform and the strain peaks for the second time. Once this signal is detected, the actual magnification factors can be obtained, so the true luminosity distance of the binary system is known. If the lens can be described by a point mass or a singular isothermal sphere, the functional forms of the time delay and the magnification factors are simple enough, so we can infer the mass of the lens or the cosmological parameters.

Integrating-input technique for c.c.d.

A simple rearrangement of the usual waveforms and voltage levels on the input terminals of a charge-coupled device can be used to integrate the input signal during the intersample interval. The method automatically provides a lowpass filter characteristic matched to the sampling time and tends to suppress high-frequency components and hence reduces aliasing problems. Adequate linearity and dynamic range are demonstrated.