De filtering to improve longitudinal resolution

As mentioned in the previous post, due to the existence of various mistaken comics in the actual processing, the azimuth resolution can not be very high, and with the improvement of resolution, the synthetic aperture time becomes longer, and in the long synthetic aperture local time, the previous assumption of radar uniform linear motion is usually no longer true, which makes the motion compensation very complicated. Another reason is that in the past, due to the limitation of signal bandwidth, the range resolution is usually at this level, in order to match the azimuth and range resolution, it is not necessary to use the full aperture, and Nashu let the beam width be reduced first through the method of pre-filtering, so as to achieve the purpose of reducing the azimuth resolution.

Upstairs is true, D2 is the highest lateral resolution theoretically achievable with focused synthetic aperture radar. However, due to many factors in practice, this resolution cannot be reached. For example, from the angle roll height of the depth of focus, in the actual processing, considering the complexity of the hardware design and the requirements of the resolution of the standby rate, the parameters of the transversely matched filter cover oscillator use the same parameter in a certain distance range.

The requirements for imaging quality are relatively high, and the focusing depth should be smaller.

The resolution of the highest subdivided rocks in the azimuth direction can reach d 2"Condition: Fruiting in the case of positive side view. Gathering under the bundle is not only defeated. Limit quarter wavelength.

Printer resolution, also known as output resolution, refers to the number of inches in both landscape and portrait directions when the output is printed. The resolution is not only related to the size of the displayed print format, but also affected by factors such as the distance between the printing dots and the printing size.

The longitudinal resolution first zone refers to the ability to distinguish the corresponding stratum thickness of two similar reflection interfaces, and the lateral resolution is the ability to distinguish the minimum distance between two adjacent geological fighting bodies in the horizontal direction, in terms of length. It is the same as the arrangement of the receiving devices in the horizontal direction and the nature of the source signal and the physical properties of the detected target.

and other factors. The smaller the value, the higher the lateral resolution.

Research BAI shows that the best resolution depends on DU

In terms of signal-to-noise spectrum, that is to say, the key to improving the resolution DAO rate is to improve the signal-to-noise spectrum. The factors affecting the resolution response rate and signal-to-noise ratio include geodetic filtering, geophone damping, dynamic correction and horizontal superposition, and deconvolution.

Geodetic filtering is equivalent to a low-pass filter, and the noise generated by the source tends to increase with frequency compared with the signal arriving at the detector at the same time, and the signal-to-noise spectrum may also decrease in the direction of high frequency compared with the signal that occurs at the same time on the record.

Therefore, it is important to overcome environmental noise, especially in the vicinity of the geophone. The dispersion in the absorbing medium needs to be compensated.

The regolith not only affects the amplitude of the signal, but also causes a nonlinear relationship with the regolith thickness and frequency. Under different damping conditions, the impulse response of the geophone is different, and the greater the damping, the sharper the impulse response, which has an attenuating effect on the low-frequency components. In the case of high low-frequency noise, the dynamic range of the instrument can be fully utilized with large damping.

Proper control of the length of the arrangement and selection of excision parameters can avoid the reduction of high-frequency signal-to-noise ratio caused by dynamic correction stretching. In fact, the reflection coefficient sequence is quite different from the white sequence, so the multi-channel average deconvolution operator is used to improve the results of deconvolution before dynamic correction.