Abstract: A method of acoustic telemetry in a drill string in a wellbore, comprises; transmitting an acoustic signal related to a parameter of interest from a transmitting location into the drill string; detecting signals propagated through the drill string at a receiving location, where the detected signals including noise; determining a drill string transfer matrix defining the propagation of signals through a transfer interval between the receiving location and the transmitting location; and using the detected signals and the drill string transfer matrix for obtaining an estimate of the acoustic signal.

Abstract: A method of acoustic telemetry in a drill string in a wellbore, comprises; transmitting an acoustic signal related to a parameter of interest from a transmitting location into the drill string; detecting signals propagated through the drill string at a receiving location, where the detected signals including noise; determining a drill string transfer matrix defining the propagation of signals through a transfer interval between the receiving location and the transmitting location; and using the detected signals and the drill string transfer matrix for obtaining an estimate of the acoustic signal.

Abstract: A method of acoustic telemetry in a drill string in a wellbore, comprises transmitting an acoustic signal related to a parameter of interest from a transmitting location into the drill string. The signals propagated through the drill string are detected at a receiving location, where the detected signals include noise. A drill string transfer matrix is determined defining the propagation of signals through a transfer interval between the receiving location and the transmitting location. The detected signals and the drill string transfer matrix are used for obtaining an estimate of the acoustic signal.

Abstract: Apparatus and methods for selectively controlling by graphics environment window the characteristics of an overlay common to multiple-windows while operating within the context of a conventional RAMDAC overlay control architecture. Window specific overlay control is accomplished by concatenating the window, masking and overlay data as an address to a mapping memory. The bit content of the mapping memory is controlled directly by the general purpose processor to selectively refine the relationship between the concatenated input as an address and the mapping memory output as the state conveyed to the overlay control of the RAMDAC. A common overlay is thus selectively modifiable by window.