| CPC G01S 15/586 (2013.01) [G01S 7/536 (2013.01)] | 9 Claims |
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1. A trajectory estimation device comprising:
at least one memory storing instructions; and
at least one processor connected to the at least one memory and configured to execute the instructions to:
acquire wave data based on a wave detected by each of a plurality of sensors disposed at intervals according to a type of a wave source to be estimated;
generate a spectrogram using the wave data, the spectrogram being a three-dimensional graph representing the wave detected by each of the plurality of sensor in a relationship of a time, a frequency, and an intensity;
extract Doppler shifts from the spectrogram, the Doppler shifts being temporal changes of frequencies extracted based on a peak having a maximum or greatest intensity in the spectrogram;
select, as a sensor pair, two of the sensors that satisfy a preset selection condition for the Doppler shifts; and
estimate a trajectory of the wave source, which is a source generating the wave, based on a positional relationship between the sensors constituting the sensor pair and a relationship of the Doppler shifts between the two sensors constituting the sensor pair, wherein
in a case where a frequency of the wave is known in advance, the at least one processor is configured to execute the instructions to:
generate a plurality of bases by shifting the frequency of the wave within a certain frequency width;
derive activation for the plurality of bases by non-negative matrix factorization;
specify a basis for which the activation has a maximum value, among the plurality of bases; and
calculate, as the Doppler shifts, curves obtained by plotting the frequency of the basis at which the activation has the maximum value.
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