Granted Patent
Utility
US 4,728,897 · App. 07/073,328
Microwave reflection survey technique for determining depth and orientation of buried objects
Inventor:
David J. Gunton
Patented Case
View Patent ↗
Granted: Mar 1, 1988
Filed: Jul 13, 1987
Inventor
David J. Gunton
Assignee (at issue)
British Gas
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.