Stator flux oriented vector control of induction motor (IM) drives for speed sensorless control has several advantages. But the application of a pure integrator for the flux estimation is difficult due to the presence of measurement noise and dc offset. To overcome these problems, some have used a programmable cascaded low pass filter (PCLPF). In this paper, it is shown that some problems still...

Offset is a geometrical nuisance when reflectors have dip. For this reason, we develop migration methods here and in the next chapter for forming images from hypothetical zero-offset seismic experiments. Although there is usually ample data recorded near zerooffset, we never record purely zero-offset seismic data. However, when we consider offset and dip together in chapter ?? we will encounter...