| 摘要 |
A method may include generating for transmission a repeating sequence of N constant-frequency pulses of width t seconds at interpulse intervals of T seconds, with each pulse in the sequence having a particular constant phase according to a quadratic phase sequence, which phase is applied to each pulse in a first sense of modulation. The method may further include modulating the phase of echo energy received from one or more objects reflecting the transmitted repeating sequence of N constant-frequency pulses with a second sense of modulation opposite to the first sense of modulation. The method may further include producing from the modulated received echo energy N unique and discrete frequency translations of the received echo energy as a function of range r of the reflecting objects, of magnitude equal to multiples of 1/NT Hz, which may preserve the spectrum of the received echo energy, forming in combination a composite signal frequency spectrum. |
| 主权项 |
1. A computer program product comprising:
at least one computer readable storage medium having computer readable program instructions embodied therewith, the computer readable program instructions, when read by a processor of a signal-processing system of an echo-ranging system, being configured to: generate for transmission a repeating sequence of N constant-frequency pulses of width t seconds at interpulse intervals of T seconds, with each pulse in the sequence having a particular constant phase according to a quadratic phase sequence, which phase is applied to each pulse in a first sense of modulation; modulate the phase of echo energy received from one or more objects reflecting the transmitted repeating sequence of N constant-frequency pulses during each receiving subinterval by the identical quadratic phase sequence used for the transmitted repeating sequence of N constant-frequency pulses, with a second sense of modulation opposite to the first sense of modulation, so that the net phase modulation applied to echo energy reflected from a particular reflecting object at a particular range r, measured in discrete units of T of round-trip echo time, is a difference between the phase of the transmitted pulses at the time of their transmission and the phase applied to the received echo energy from range r, in either sense of the difference; and produce from the modulated received echo energy N unique and discrete frequency translations of the received echo energy as a function of range r of the reflecting objects, of magnitude equal to multiples of 1/NT Hz, which frequency translations preserve the spectrum of the received echo energy, forming in combination a composite signal frequency spectrum. |
