Multiple frequency through-the-wall motion detection and ranging using a difference-based estimation technique
First Claim
1. A method for detecting range to a moving object, comprising the steps of:
- projecting continuous wave energy at two different frequencies towards the moving object from an antenna; and
, estimating range from the antenna to the moving object based on the phase difference between outgoing and reflected waves of the two frequencies at the antenna.
1 Assignment
0 Petitions
Accused Products
Abstract
A multi-tone CW radar (14) is used to project signals from an antenna (22) and to receive returns with the same antenna. The phase differences between the outgoing signals and the returns are analyzed to determine the existence of motion and the range to a moving object (10). A model is made which has range as its major parameter. A waveform associated with the phase difference between outgoing signals and returns for one of the tones is compared to templates produced by the model to determine which has a range that most closely matches. By varying the range parameters, when a match is detected the range to the object can be obtained even if its motion is pseudorandom. If the range is measured with multiple units it is possible to measure the location of the object. This can be done assuming a grid and algorithmically combining the ranges from the units.
-
Citations
17 Claims
-
1. A method for detecting range to a moving object, comprising the steps of:
-
projecting continuous wave energy at two different frequencies towards the moving object from an antenna; and
,estimating range from the antenna to the moving object based on the phase difference between outgoing and reflected waves of the two frequencies at the antenna. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for estimating the range to a non-uniformly-moving object, comprising the steps of:
-
simultaneously projecting from an antenna continuous wave energy at two different frequencies towards the moving object which reflects incident wave energy back to the antenna; and
,estimating the range to the non-uniformly-moving object based on the phase difference between outgoing and reflected waves of the two frequencies reflected by the object to the antenna. - View Dependent Claims (12, 13)
-
-
14. Apparatus for the estimation of the range to a moving object, comprising:
-
a two-tone radar for generating continuous wave energy at two different frequencies;
an antenna coupled to said radar for simultaneously projecting continuous wave energy therefrom;
a pair of mixers coupled to said antenna and said radar for generating waveforms corresponding respectively to the phase difference between outgoing and reflected energy at said antenna for each of said two different frequencies; and
,a range estimation unit coupled to said pair of mixers for estimating range to said moving object. - View Dependent Claims (15, 16, 17)
-
Specification