Wen Ni Chang

US Patent:

59837306, Nov 16, 1999

Filed:

Nov 5, 1997

Appl. No.:

8/964577

Inventors:

William Freund - Houston TX
Winsor Letton - Houston TX
James McClellan - Marietta GA
Baocang Jia - Houston TX
Anni Wey - Houston TX
Wen Chang - Sugar Land TX

Assignee:

Daniel Industries, Inc. - Houston TX

International Classification:

G01F 166

US Classification:

7386128

Abstract:

An apparatus for measuring the time of flight of a signal is provided. The apparatus for measuring the time of flight of a signal comprises a transmitter for emitting a signal, a receiver for receiving the signal from the transmitter, and means for detecting the onset of the signal as it arrives at the receiver such that the period of time from emission by the transmitter to the time the receiver initially receives the signal can be determined. In another embodiment, the present invention provides a method for determining the time of flight of a signal comprising the steps of receiving a transmitted signal, operating on the received signal for generating a pre-conditioned signal, conditioning the pre-conditioned signal for removing irregularities therefrom for generating a conditioned signal, operating on the conditioned signal to form a discriminated signal, and determining the critical point of the discriminated signal such that the critical point can be used to determine the time of flight of the signal from the instant of transmission to the instant reception.