US 12,386,050 B2
Compensation method for obtaining phase-coherent still images with a bistatic radar
Heinrich Fragner, St. Pölten (AT)
Assigned to BEYOND GRAVITY AUSTRIA GMBH, Vienna (AT)
Filed by Beyond Gravity Austria GmbH, Vienna (AT)
Filed on Sep. 20, 2022, as Appl. No. 17/948,818.
Claims priority of application No. A 115/2022 (AT), filed on Jun. 2, 2022.
Prior Publication US 2023/0393255 A1, Dec. 7, 2023
Int. Cl. G01S 13/28 (2006.01); G01S 13/00 (2006.01)
CPC G01S 13/288 (2013.01) [G01S 13/003 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method of locating a point P that is stationary and located on the earth's surface using bistatic radar with at least one transmitter and at least one receiver, wherein there is relative movement of the transmitter and/or receiver to the point P, the method comprising:
a) emitting a measurement signal modulated onto a carrier wave from the transmitter to the earth's surface,
b) receiving the measurement signal reflected from the earth's surface during a measurement period Δt in the receiver,
c) during the measurement period Δt continuously or at intervals determining a runtime of the measurement signal along a signal path from the transmitter via the point P to the receiver,
d) during the measurement period Δt continuously or at intervals determining a path length of the measurement signal along the signal path,
e) continuously or at intervals compensating the runtime of the measurement signal changing due to the relative movement of the point P to the transmitter and/or receiver during the measurement period Δt using the path length changing during the measurement period Δt,
f) calculating a distance of the point P from the transmitter and/or receiver based on the compensated runtime and a signal propagation speed of the measurement signal,
wherein the point P is located at a defined point relative to end points A and B of a line L, one end point A being a reflection point of the measurement signal at which an angle of incidence at the beginning of the measurement period Δt is equal to an angle of reflection, and the other end point B being the reflection point of the measurement signal at which the angle of incidence at the end of the measurement period Δt is equal to the angle of reflection.