In [20], the relation and difference between the general echo model and the classical model were minutely analyzed.
In this paper, our goal is to analyze a general echo model and construct a new CS matrix for the SAR imaging.
The remainder of this paper is structured as follows: after introducing the notation in Section 2, frequently used echo path models and their adaptation are reviewed in Sections 3.1 and 3.2, respectively.
We use the partial differential Maxwell's equations to derive the electronic field and then obtain the general echo model in frequency domain and time domain.
However, most of the past research works are focused on the classical echo model for SAR [18] and ISAR image [19].
After analyzing the relationship between the general echo model in frequency domain and the existing model in time domain, a compressive sensing (CS) matrix is constructed from random partial Fourier matrices for processing the range CS SAR imaging.
Even if some approximation about antenna radiation has been made, we can also find the difference between the above model and the transitional echo model, which is as simple as the summing the delayed signal of the transmitted signal.
"They were to compose essays in French that echoed these models, and could choose their own subject matter". After her first stay in Brussels was brought to an abrupt halt in November 1842 by the death of her aunt, Brontë returned to the city the following year to become an English teacher at the boarding house run by Heger's wife, Claire Zoë Parent.
On the other hand, the nonlinear distortions created by amplifiers and transducers in miniaturized loudspeakers require dedicated nonlinear echo-path models and are still a very active research topic [8, 9].
Previously, we established the echo model of target with micro-motion, and time-frequency transformation of the echoed signal is applied to gain the time-varying micro-Doppler frequency features of target.
