JPH07270529A - Image regenerating and processing system of synthetic aperture radar - Google Patents

Abstract

PURPOSE:To reduce the scale of hardware by extracting alternatively a desired combination of transmission and reception polarization methods, in regard to a multiparametric SAR image regenerating and processing system wherein the combination of the transmission and reception polarization methods is switched over on a time sharing basis. CONSTITUTION:The number of SAR signal data is counted by a counter 2, a value obtained by this counting is compared with the content f a counter value setting table 1 by a data extracting device 3 and only the SAR data at the time when they are coincident with each other are delivered to an SAR image reproducing and processing device 4 and reproduced. When the number of timings of the SAR signal data of which the reception is desired is set beforehand in the table 1, only the desired SAR data can be extracted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic aperture radar (hereinafter simply referred to as SAR) image reproduction processing system, and more particularly to a multiparametric SAR image reproduction processing system.

[0002]

2. Description of the Related Art In the technical field of remote sensing using a flying object such as an artificial satellite or an aircraft, a SAR (Synthetic) that can obtain a high resolution image using a microwave band is used as a sensor for imaging the state of the ground surface. Ap
The image reader is used.

As the latest technology of this SAR system,
As shown in FIG. 2, four types of transmission / reception polarization combinations (HH, HV, VH, VV) of vertical (V) and horizontal (H) polarizations are transmitted and received while sequentially and selectively switching in a time division manner. In recent years, a multiparametric SAR processing device has been proposed which reproduces an image from video data obtained by SAR.

FIG. 2 shows a combination of these four types of transmission / reception polarized waves.
As shown in (A), cyclically switching in a time-division manner is not possible to obtain sufficiently satisfactory video data with only one type of polarization combination due to changes in the environment or changes in the ground surface. By using all combinations of wave methods, it is possible to sufficiently cope with these environmental changes and changes in the ground surface.

In this case, four Ss corresponding to four combinations of transmission and reception polarization systems (HH, HV, VH, VV) are provided.
An AR image reproduction processing device is prepared in advance, and each of these four types of SAR raw data is supplied to the corresponding SAR image reproduction processing device to perform image reproduction processing.

[0006]

In such a conventional multi-parametric SAR image reproduction processing system, four image reproduction processing devices are provided corresponding to four kinds of SAR raw data, which are all combinations of transmission and reception polarization systems. It is necessary to provide a system, and it is not a good idea in terms of hardware and is disadvantageous in terms of cost.

Therefore, the present invention has been made to solve the above drawbacks of the prior art, and its purpose is to select only SAR raw data by a desired combination of transmission and reception polarization systems. It is to provide an SAR image reproduction processing system that requires only a single image reproduction processing device.

[0008]

According to the present invention, there is provided a synthetic aperture radar obtained by transmitting and receiving while sequentially and selectively switching four combinations of transmission and reception polarizations of vertical and horizontal polarizations in a time division manner. An image reproduction processing system for a synthetic aperture radar that reproduces an image from video data, comprising extraction means for extracting only one type of video data set in advance out of a combination of four types of transmission / reception polarizations. An image reproduction processing system for

[0009]

[Function] Only the SAR raw data obtained by one kind of combination specified in advance among the four kinds of transmission / reception polarization method combinations,
By selectively extracting in synchronization with the switching timing of the combination of the transmission and reception polarization systems, a single SAR image reproduction processing device is used.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system block diagram of an embodiment of the present invention.

In FIG. 1, multiparametric SAR signal data from an unillustrated SAR is input to a counter 2 and a data extraction device 3, respectively.

The data extraction device 3 compares the count value of the counter 2 with the preset value set in the counter (count) value setting table, selects the SAR signal data when the two match, and selects the SAR. It is sent to the image reproduction processing device 4.

Here, in the multiparametric SAR signal data, as shown in FIG. 2A, four types of combinations of transmission and reception polarization systems are time-divisionally in the order of (HH, HV, VH, VV). It is the data when it is switched alternatively,
Since each data is unit pulse data, the counter 2 counts this data pulse.

In this case, if the counter 2 is a quaternary counter, the count content (0, 1, 2, 3) cyclically changes, so "0" is changed to "HH" and "1" is changed. "HV"
In addition, "2" can correspond to "VH" and "3" can correspond to "VV".

Therefore, in the counter value setting table 1, one of the count values 0 to 3 corresponding to the type desired to be received is set by a selection signal for selecting the type of the combination of transmission and reception polarization systems from the outside. As a result, the data extraction device 3 compares the count value of the counter 2 with the set value of the table 1 and extracts the SAR signal data only when they match.

By doing so, only the SAR signal data of the desired transmission / reception polarization system is selectively supplied to the SAR image reproduction processing device 4 and the reproduction image processing becomes possible.

Prior to the SAR signal data processing, a combination type of transmission / reception polarization systems to be periodically extracted is set in the counter value setting table 1, and the best one of the SAR image reproduction processing outputs obtained by this is set. The corresponding transmission / reception polarization method combination type is newly set in Table 1.
After that, if the SAR signal data processing is performed in this state, the best combination type of the transmission / reception polarization methods will be selected.

[0018]

As described above, according to the present invention, the SAR in which the transmission / reception polarization system is switched in a time division manner.
Since only the desired polarization method is extracted from the signal data, it is sufficient to provide a single SAR image reproduction processing device, which is advantageous in terms of hardware and cost.

Further, since only the SAR signal data having the best reception state can be extracted, there is an effect that an image with high sensitivity can be obtained.

[Brief description of drawings]

FIG. 1 is a system block diagram of an embodiment of the present invention.

FIG. 2A is a diagram showing an example of a time-arrangement sequence of a transmission / reception polarization system of multiparametric SAR raw data, and FIG.
FIG. 4 is a diagram for explaining abbreviations of transmission / reception polarization.

[Explanation of symbols]

 1 counter value setting table 2 counter 3 data extraction device 4 SAR image reproduction processing device

Claims (3)

[Claims] 1. A synthetic aperture radar that reproduces an image from video data obtained by a synthetic aperture radar obtained by transmitting and receiving while sequentially and selectively switching four types of combinations of vertically and horizontally polarized transmission and reception polarized waves in a time division manner. The image reproduction processing system according to claim 1, further comprising: an extracting unit that extracts only one type of video data set in advance out of a combination of four types of transmitted and received polarized waves. 2. The extracting means includes identification means for identifying a combination of transmission / reception polarizations to be extracted, and selection means for selecting a combination of transmission / reception polarizations identified by the identification means. The image reproduction processing system according to claim 1. 3. The specifying means preliminarily provides a counting means for performing a cyclic counting operation in synchronization with the switching timing of the combination of the transmission / reception polarization and a specific count value corresponding to the combination of the transmission / reception polarization to be extracted. 3. The setting means for setting, wherein the video data is selected by the selecting means when the specific count value and the count value of the counting means match each other. Image reproduction processing system.