| 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 non-transitory 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, configuring the processor 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; 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. |
