CN116224379B

CN116224379B - NBRCS correction method and device, electronic equipment and storage medium

Info

Publication number: CN116224379B
Application number: CN202310504550.6A
Authority: CN
Inventors: 黄飞雄; 王先毅; 夏俊明; 尹聪; 孙越强; 杜起飞; 白伟华; 仇通胜; 蔡跃荣; 孟祥广; 柳聪亮; 谭广远; 胡鹏; 吴汝晗; 刘成; 李福�; 王冬伟; 王卓焱; 张�浩; 李伟
Original assignee: National Space Science Center of CAS
Current assignee: National Space Science Center of CAS
Priority date: 2023-05-06
Filing date: 2023-05-06
Publication date: 2023-09-12
Anticipated expiration: 2043-05-06
Also published as: CN116224379A

Abstract

The embodiment of the application provides an NBRCS correction method, an NBRCS correction device, electronic equipment and a storage medium. The method comprises the following steps: according to the observation data of the target space-based GNSS-R, calculating and obtaining a target MSB corresponding to a receiver of the target space-based GNSS-R and a target NBRCS corresponding to the target MSB; acquiring a target NBRCS correction value corresponding to the target MSB based on a relation mapping model between a pre-established MSB and the NBRCS correction value under the condition that the target MSB is in a preset MSB range; and correcting the target NBRCS based on the target NBRCS correction value to obtain a corrected NBRCS. The embodiment of the application can inhibit the observed quantity deviation caused by radio frequency interference.

Description

NBRCS correction method and device, electronic equipment and storage medium

Technical Field

The application relates to the technical field of satellite navigation, in particular to an NBRCS correction method, an NBRCS correction device, electronic equipment and a storage medium.

Background

The global navigation satellite system (Global Navigation Satellite System, GNSS) can provide accurate positioning, navigation and timing functions (PNT). In addition to PNT, GNSS may be used for global remote sensing, one of which is global navigation satellite reflected signal remote sensing (GNSS Reflectometry, GNSS-R), which is a novel remote sensing technology that utilizes GNSS signals reflected from the surface of the earth. The GNSS-R technology based on the space base is used for carrying the GNSS reflection receiver on a low-orbit satellite, so that the global meteorological elements and ocean elements (such as sea surface wind speed and the like) can be observed.

The L-band GNSS signals have lower energy than other broadcast, communication and radar signals and are therefore more susceptible to radio frequency interference (Radio Frequency Interference, RFI). Because the receiver of the space-based GNSS-R is located on the low-orbit satellite, the receiver is affected by the global distributed interference sources, such as the interference of reflected signals from GNSS satellites except the tracking GNSS satellites, GNSS interference signals from the earth surface, L-band communication signals and the like.

Currently, there is no way to efficiently handle GNSS-R interference.

Disclosure of Invention

The embodiment of the application provides an NBRCS correction method, an NBRCS correction device, electronic equipment and a storage medium, so as to effectively process GNSS-R interference.

In order to solve the technical problems, the embodiment of the application is realized as follows:

in a first aspect, an embodiment of the present application provides a NBRCS correction method, where the method includes:

according to the observation data of the target space-based GNSS-R, calculating and obtaining a target MSB corresponding to a receiver of the target space-based GNSS-R and a target NBRCS corresponding to the target MSB;

acquiring a target NBRCS correction value corresponding to the target MSB based on a relation mapping model between a pre-established MSB and the NBRCS correction value under the condition that the target MSB is in a preset MSB range;

And correcting the target NBRCS based on the target NBRCS correction value to obtain a corrected NBRCS.

Optionally, before the calculating, according to the observed data of the target space-based GNSS-R, the target MSB corresponding to the receiver of the space-based GNSS-R and the target NBRCS corresponding to the target MSB, the method further includes:

according to the observation data of the space-based GNSS-R in the preset time length, calculating and obtaining an MSB corresponding to a receiver of the space-based GNSS-R and an NBRCS corresponding to the MSB;

determining an NBRCS correction value corresponding to the MSB according to the MSB and the corresponding NBRCS within a preset MSB range;

and establishing the relation mapping model based on the MSB and the corresponding NBRCS correction value within a preset MSB range.

Optionally, the determining, according to the MSB and the corresponding NBRCS within the preset MSB range, an NBRCS correction value corresponding to the MSB includes:

calculating to obtain an average value of the MSBs in a preset MSB range, and obtaining an MSB average value;

determining a reference NBRCS corresponding to the MSB within a preset MSB range based on the MSB and the MSB mean value within the preset MSB range;

and determining an NBRCS correction value corresponding to the MSB in a preset MSB range according to the reference NBRCS and the NBRCS corresponding to the MSB in the preset MSB range.

Optionally, the determining, based on the MSB and the MSB mean value within a preset MSB range, a reference NBRCS corresponding to the MSB within the preset MSB range includes:

acquiring a middle MSB in a preset range corresponding to the MSB mean value from the MSBs in the preset MSB range;

and determining a reference NBRCS corresponding to the MSB in a preset MSB range according to the NBRCS corresponding to the middle MSB.

Optionally, the determining, according to the NBRCS corresponding to the middle MSB, a reference NBRCS corresponding to the MSB in a preset MSB range includes:

when the number of the intermediate MSBs is one, acquiring an NBRCS corresponding to the intermediate MSBs, and taking the NBRCS as the reference NBRCS; or alternatively

When the number of intermediate MSBs is plural, an NBRCS mean value of the NBRCS corresponding to the intermediate MSBs is calculated, and the NBRCS mean value is used as the reference NBRCS.

Optionally, the determining, according to the reference NBRCS and the NBRCS corresponding to the MSBs within the preset MSB range, the NBRCS correction value corresponding to the MSBs within the preset MSB range includes:

calculating to obtain an NBRCS difference value between the reference NBRCS and the NBRCS corresponding to the MSB in a preset MSB range;

And taking the NBRCS difference value as the NBRCS correction value.

Optionally, the calculating, according to the observation data of the target space-based GNSS-R, the target MSB corresponding to the receiver of the target space-based GNSS-R includes:

acquiring a quantized value corresponding to each second of analog signal in the observed data and the number of sampling points in each second of data;

and calculating a target MSB corresponding to the receiver of the target space-based GNSS-R based on a preset function, the quantized value and the number of sampling points.

Optionally, the correcting the target NBRCS based on the target NBRCS correction value, to obtain a corrected NBRCS, includes:

calculating to obtain NBRCS sum values between the target NBRCS correction value and the target NBRCS;

the NBRCS sum value is taken as the corrected NBRCS.

Optionally, after the calculating, the target MSB corresponding to the receiver of the target space-based GNSS-R and the target NBRCS corresponding to the target MSB further include:

processing the relation mapping model based on a linear extrapolation method under the condition that the target MSB is out of a preset MSB range to obtain a reference NBRCS correction value corresponding to the target MSB;

and carrying out correction processing on the target NBRCS based on the reference NBRCS correction value to obtain a corrected NBRCS.

In a second aspect, an embodiment of the present application provides an NBRCS correction apparatus, the apparatus comprising:

the target MSB calculation module is used for calculating and obtaining a target MSB corresponding to a receiver of the target space-based GNSS-R and a target NBRCS corresponding to the target MSB according to the observation data of the target space-based GNSS-R;

a target correction value obtaining module, configured to obtain a target NBRCS correction value corresponding to the target MSB based on a relationship mapping model between a pre-established MSB and an NBRCS correction value when the target MSB is within a preset MSB range;

and the NBRCS correction module is used for correcting the target NBRCS based on the target NBRCS correction value to obtain a corrected NBRCS.

Optionally, the apparatus further comprises:

the MSB calculation module is used for calculating and obtaining an MSB corresponding to a receiver of the space-based GNSS-R and an NBRCS corresponding to the MSB according to the observation data of the space-based GNSS-R in the preset time period;

an NBRCS correction value determining module, configured to determine an NBRCS correction value corresponding to the MSB according to the MSB and the corresponding NBRCS within a preset MSB range;

and the relation mapping model building module is used for building the relation mapping model based on the MSB and the corresponding NBRCS correction value within a preset MSB range.

Optionally, the NBRCS correction value determining module includes:

the MSB average value calculation unit is used for calculating an average value of MSBs positioned in a preset MSB range to obtain an MSB average value;

a reference NBRCS determining unit configured to determine a reference NBRCS corresponding to the MSBs located within a preset MSB range based on the MSBs located within the preset MSB range and the MSB mean value;

and the NBRCS correction value determining unit is used for determining the NBRCS correction value corresponding to the MSB in the preset MSB range according to the reference NBRCS and the NBRCS corresponding to the MSB in the preset MSB range.

Optionally, the reference NBRCS determining unit includes:

a middle MSB obtaining subunit, configured to obtain a middle MSB in a preset range corresponding to the MSB mean value from among the MSBs in the preset MSB range;

and the reference NBRCS determining subunit is used for determining the reference NBRCS corresponding to the MSB in the preset MSB range according to the NBRCS corresponding to the middle MSB.

Optionally, the reference NBRCS determination subunit includes:

a first reference NBRCS obtaining subunit, configured to obtain, when the number of intermediate MSBs is one, an NBRCS corresponding to the intermediate MSBs, and take the NBRCS as the reference NBRCS;

And a second reference NBRCS obtaining subunit configured to calculate, when the number of intermediate MSBs is plural, an NBRCS mean value of the NBRCS corresponding to the intermediate MSBs, and take the NBRCS mean value as the reference NBRCS.

Optionally, the NBRCS correction value determining unit includes:

an NBRCS difference calculating subunit, configured to calculate an NBRCS difference between the reference NBRCS and an NBRCS corresponding to the MSB located in a preset MSB range;

and a reference NBRCS acquisition subunit, configured to take the NBRCS difference value as the NBRCS correction value.

Optionally, the target MSB calculation module includes:

the sampling data acquisition unit is used for acquiring a quantized value corresponding to each second of analog signal in the observed data and the number of sampling points in each second of data;

and the target MSB calculating unit is used for calculating and obtaining a target MSB corresponding to the receiver of the target space-based GNSS-R based on a preset function, the quantized value and the sampling point number.

Optionally, the NBRCS correction module includes:

an NBRCS sum value calculation unit configured to calculate an NBRCS sum value between the target NBRCS correction value and the target NBRCS;

and a corrected NBRCS acquisition unit configured to use the NBRCS sum value as the corrected NBRCS.

Optionally, the apparatus further comprises:

the reference correction value acquisition module is used for processing the relation mapping model based on a linear extrapolation method to obtain a reference NBRCS correction value corresponding to the target MSB under the condition that the target MSB is out of a preset MSB range;

and the corrected NBRCS acquisition module is used for carrying out correction processing on the target NBRCS based on the reference NBRCS correction value to obtain a corrected NBRCS.

In a third aspect, an embodiment of the present application provides an electronic device, including:

a memory, a processor, and a computer program stored on the memory and executable on the processor, which when executed by the processor, implements the NBRCS correction method of any of the above.

In a fourth aspect, embodiments of the present application provide a readable storage medium, which when executed by a processor of an electronic device, enables the electronic device to perform the NBRCS correction method of any of the above.

In the embodiment of the application, the target MSB corresponding to the receiver of the target space-based GNSS-R and the target NBRCS corresponding to the target MSB are calculated according to the observation data of the target space-based GNSS-R. And under the condition that the target MSB is in the preset MSB range, acquiring a target NBRCS correction value corresponding to the target MSB based on a relation mapping model between the pre-established MSB and the NBRCS correction value. And correcting the target NBRCS based on the target NBRCS correction value to obtain a corrected NBRCS. According to the embodiment of the application, the relation mapping model between the MSB and the NBRCS correction value is established in advance, so that the correction of any observed quantity NBRCS can be realized, and the observed quantity deviation caused by radio frequency interference can be effectively restrained.

The foregoing description is only an overview of the present application, and is intended to be implemented in accordance with the teachings of the present application in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present application more readily apparent.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments of the present application will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of the steps of an NBRCS correction method according to an embodiment of the present application;

FIG. 2 is a flowchart illustrating steps of a method for creating a relational mapping model according to an embodiment of the present application;

FIG. 3 is a flowchart illustrating steps of a method for determining an NBRCS correction value according to an embodiment of the present application;

FIG. 4 is a flowchart of steps of a method for determining a reference NBRCS according to an embodiment of the present application;

fig. 5 is a step flowchart of a reference NBRCS acquisition method according to an embodiment of the present application;

FIG. 6 is a flowchart illustrating steps of a method for obtaining an NBRCS correction value according to an embodiment of the present application;

FIG. 7 is a flowchart illustrating steps of a method for calculating a target MSB according to an embodiment of the present application;

FIG. 8 is a flowchart illustrating steps of a modified NBRCS acquisition method according to an embodiment of the present application;

FIG. 9 is a flowchart illustrating steps of another modified NBRCS acquisition method according to an embodiment of the present application;

fig. 10 is a schematic diagram of a structure of a reflection receiver according to an embodiment of the present application;

FIG. 11 is a schematic diagram of ADC quantization value distribution without interference according to an embodiment of the present application;

FIG. 12 is a schematic diagram of ADC quantization value distribution in the presence of interference according to an embodiment of the present application;

FIG. 13 is a schematic diagram of an overall data processing flow according to an embodiment of the present application;

FIG. 14 is a schematic diagram of a relationship between NBRCS and MSB provided by an embodiment of the present application;

FIG. 15 is a schematic structural diagram of an NBRCS correction device according to an embodiment of the present application;

fig. 16 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Currently, PNT application-based interference has been widely studied in the past, however, interference studies for space-based GNSS-R applications are currently less. On the one hand, the GNSS interferers for PNT applications are typically located in the vicinity of the receiver, while the receiver of the space-based GNSS-R is affected by the globally distributed interferers due to being on low-orbit satellites; on the other hand, the observed quantity of PNT application is mainly distance (such as pseudo-range, phase, etc.), while the observed quantity of space-based GNSS-R is usually the energy of the reflected signal, so the influence of the interference is different. Furthermore, because of the limited amount of data transmitted from the satellite to the ground, the space-based GNSS-R observations received on the ground are typically delay-Doppler maps (DDMs), rather than raw intermediate frequency sampled data, and thus many interference suppression methods based on raw intermediate frequency sampled data are not available.

The NBRCS (Normalized Bistatic Radar Cross Section, normalized bistatic radar scattering interface coefficient) is the main observables of the sea surface wind speed inversion, calculated from the delay-Doppler plot. When the interference signal exists, the energy of the voltage signal input into the ADC exceeds the quantization dynamic range of the ADC, so that quantization errors and energy loss of the received signal are caused, DDM power is low, NBRCS is low, and deviation is generated in the inverted wind speed. Thus, when there is disturbance, the inverted sea surface wind speed can be corrected by correcting the NBRCS.

Next, the correction process of the NBRCS will be described in detail with reference to specific embodiments.

Referring to fig. 1, a step flow chart of an NBRCS correction method provided by an embodiment of the present application is shown, and as shown in fig. 1, the NBRCS correction method may include: step 101, step 102 and step 103.

Step 101: and according to the observed data of the target space-based GNSS-R, calculating to obtain a target MSB corresponding to a receiver of the target space-based GNSS-R and a target NBRCS corresponding to the target MSB.

The embodiment of the application can be applied to the scene of correcting any observed quantity NBRCS by combining a pre-established relation mapping model between MSB and NBRCS correction values so as to effectively inhibit observed quantity deviation caused by radio frequency interference.

First, the structure of the reflection receiver can be described as follows with reference to fig. 10.

As shown in fig. 10, the reflection receiver may include: antenna, low noise amplification, down conversion, filtering and automatic gain control, analog to digital converter and DDM correlator. The voltage signal received by the antenna is converted into intermediate frequency data through down-conversion after being amplified by low noise amplification. The intermediate frequency data is filtered and then reaches an automatic gain control (Automatic gain control, AGC). The automatic gain control automatically adjusts the gain of the automatic gain control according to the voltage of the signal so as to adjust the voltage of the signal. For space-based GNSS-R applications, however, the gain of the automatic gain control is typically a fixed value in order to obtain accurate reflected signal power for scaling. An analog-to-digital converter (analog to digital converter, ADC) converts the voltage value of the signal to a digital value with a certain quantization resolution. The digital signal is finally processed by a DDM correlator to obtain a delay-Doppler graph. For sea surface wind speed inversion, the main observed quantity normalized radar cross section coefficient (NBRCS) can be calculated from the delay-Doppler diagram.

The interference source received by the space-based GNSS-R receiver is mainly from the reflected signals of the GNSS satellites other than the tracking GNSS satellites, and the GNSS interference signals from the earth surface, L-band communication signals, and the like. Taking the 4-bit ADC as an example, the quantized values after converting the analog signal into the digital signal are { -8, -7, …,0,1, …,7}, and when there is no interference, the distribution of these 16 quantized values should be close to the normal distribution, as in fig. 11, so the magnitude of the MSB should be around a certain fixed value. When there is interference, the distribution of 16 quantized values is no longer normal because part of the signal strength exceeds the quantization range of the ADC, as in fig. 12, where the MSB will be greater than normal. Thus, the size of the MSB can be used to measure the size of the quantization error.

When the observed quantity NBRCS of the receiver of the target space-based GNSS-R is corrected, the target MSB corresponding to the receiver of the target space-based GNSS-R and the target NBRCS corresponding to the target MSB can be calculated according to the observed data of the target space-based GNSS-R. In this example, the MSB is a Mean Square Bit value (Mean Square Bit) that may be used to indicate the Mean Square Bit value of a plurality of sampling points contained in the receiver sampling data per second. For example, taking a 4-bit ADC as an example, the quantization value after converting an analog signal to a digital signal is { -8, -7, …,0,1, …,7}. For sampling frequency (e.g., 16MHz, etc.), the analog-to-digital converted sample data contains +/1 second in total>The sampled points are computed for their mean squared bit values (i.e., MSBs).

In this example, the target MSB may be one MSB or a plurality of MSBs, and in particular, the number of target MSBs may be determined according to the actual situation, which is not limited in this embodiment.

The calculation process for the target MSB may be described in detail as follows in connection with fig. 7.

Referring to fig. 7, a flowchart of steps of a target MSB calculation method according to an embodiment of the present application is shown. As shown in fig. 7, the target MSB calculation method may include: step 701 and step 702.

Step 701: and obtaining a quantized value corresponding to each second of analog signal in the observed data and the number of sampling points in each second of data.

In this embodiment, after the observation data is obtained, a quantized value corresponding to an analog signal per second in the observation data and the number of sampling points in the data per second may be acquired.

Step 702: and calculating a target MSB corresponding to the receiver of the target space-based GNSS-R based on a preset function, the quantized value and the number of sampling points.

After the quantized value and the number of sampling points are obtained, a target MSB corresponding to the receiver of the target space-based GNSS-R can be calculated based on a preset function, the quantized value and the number of sampling points. The calculation of the target MSB can be as shown in the following equation (1):

（1）

In the above-mentioned formula (1),16 quantized values for 4-bit ADC, < >>The number of corresponding sampling points in the 1 second data for each quantized value.

In a specific implementation, the MSB is generally in the range of [10, 20]. When there is no interference, the MSB is typically around 13.5, and the specific value depends on the receiver, which is not limited in this embodiment.

The calculation of the target NBRCS is a conventional observed quantity in GNSS-R wind speed inversion, and an existing common calculation mode can be adopted, and the calculation mode of the target NBRCS is not limited in the embodiment.

After the target MSB corresponding to the receiver of the target space-based GNSS-R and the target NBRCS corresponding to the target MSB are calculated according to the observation data of the target space-based GNSS-R, step 102 is performed.

Step 102: and under the condition that the target MSB is in a preset MSB range, acquiring a target NBRCS correction value corresponding to the target MSB based on a relation mapping model between the pre-established MSB and the NBRCS correction value.

The preset MSB range refers to a range of MSBs indicated in a relation map model between the preset MSBs and the NBRCS correction values, and in this example, the MSB range may be [10, 20], but is not limited thereto, and in particular, the specific range for the preset MSBs may be determined according to traffic demands, which is not limited thereto by the present embodiment.

A relationship mapping model between MSB and NBRCS correction values may be used to indicate the mapping relationship between MSB and NBRCS. The process of building the relationship mapping model may be described in detail below in conjunction with FIG. 2.

Referring to fig. 2, a flowchart of steps of a method for creating a relational mapping model according to an embodiment of the present application is shown. As shown in fig. 2, the relationship mapping model building method may include: step 201, step 202 and step 203.

Step 201: and calculating to obtain MSB corresponding to a receiver of the space-based GNSS-R and NBRCS corresponding to the MSB according to the observed data of the space-based GNSS-R within a preset time period.

In this embodiment, when a mapping model of the relationship between the MSB and the NBRCS correction value is established, observation data (such as semi-annual global data) of the space-based GNSS-R (the number of GNSS-R may be one or more) within a preset period of time may be obtained, and the MSB corresponding to the receiver of the space-based GNSS-R and the NBRCS corresponding to the MSB are calculated. The calculation manners of the MSB and the NBRCS may be described in the steps 701 to 702, which are not described herein.

After calculating the MSB corresponding to the receiver of the space-based GNSS-R and the NBRCS corresponding to the MSB according to the observed data of the space-based GNSS-R within the preset time period, step 202 is performed.

Step 202: and determining an NBRCS correction value corresponding to the MSB according to the MSB and the corresponding NBRCS in a preset MSB range.

After the MSBs and the NBRCSs corresponding to the MSBs are calculated, the MSBs within the preset MSB range may be acquired, and the NBRCS correction value corresponding to the MSBs (i.e., the MSBs within the preset MSB range) may be determined according to the MSBs within the preset MSB range and the corresponding NBRCSs. Specifically, an average value of MSBs within the preset MSB range may be calculated, and a reference NBRCS may be determined according to the average value and the MSBs, and further, an NRRCS correction value corresponding to an MSB within the MSB range may be determined according to the reference NBRCS and an NBRCS corresponding to an MSB within the preset MSB range. This implementation may be described in detail below in conjunction with fig. 3.

Referring to fig. 3, a flowchart of steps of a method for determining an NBRCS correction value according to an embodiment of the present application is shown. As shown in fig. 3, the NBRCS correction value determining method may include: step 301, step 302 and step 303.

Step 301: and calculating to obtain an average value of the MSBs in a preset MSB range, and obtaining an MSB average value.

In the present embodiment, after the MSBs within the preset MSB range are acquired, the average value of the MSBs within the preset MSB range may be calculated, resulting in an MSB average value.

After calculating the average value of MSBs within the preset MSB range to obtain an MSB average value, step 302 is performed.

Step 302: determining a reference NBRCS corresponding to the MSBs within a preset MSB range based on the MSBs and the MSB mean values within the preset MSB range.

After calculating the average value of the MSBs within the preset MSB range to obtain the MSB average value, the reference NBRCS corresponding to the MSBs within the preset MSB range may be determined based on the MSBs within the preset MSB range and the MSB average value. Specifically, the middle MSB in the preset range corresponding to the MSB mean value among the MSBs in the preset MSB range may be acquired. And determines a reference NBRCS from the NBRCS corresponding to the intermediate MSBs. This implementation may be described in detail below in conjunction with fig. 4.

Referring to fig. 4, a step flow diagram of a reference NBRCS determination method provided by an embodiment of the present application is shown. As shown in fig. 4, the reference NBRCS determination method may include: step 401 and step 402.

Step 401: and acquiring the middle MSB in the preset range corresponding to the MSB mean value in the MSB in the preset MSB range.

In this embodiment, after the MSB mean value is calculated, the middle MSB in the preset range corresponding to the MSB mean value among the MSBs in the preset MSB range may be acquired. For example, the preset range may be ±1, and after obtaining the MSB mean value, the MSB within the MSB mean value ±1, that is, the middle MSB, among the MSBs within the preset MSB range, may be acquired.

It will be appreciated that the above examples are only examples listed for better understanding of the technical solution of the embodiments of the present application, and are not to be construed as the only limitation of the present embodiments.

After acquiring the middle MSB in the preset range corresponding to the MSB mean value among the MSBs in the preset MSB range, step 402 is performed.

Step 402: and determining a reference NBRCS corresponding to the MSB in a preset MSB range according to the NBRCS corresponding to the middle MSB.

After the middle MSB is acquired, a reference NBRCS corresponding to the MSB located in the preset MSB range may be determined according to the NBRCS corresponding to the middle MSB. Specifically, the reference NBRCS may be determined in common from the number of intermediate MSBs, and the implementation process may be described in detail below in connection with fig. 5.

Referring to fig. 5, a step flow diagram of a reference NBRCS acquisition method provided by an embodiment of the present application is shown. As shown in fig. 5, the reference NBRCS acquisition method may include: step 501 and step 502.

Step 501: when the number of intermediate MSBs is one, an NBRCS corresponding to the intermediate MSBs is acquired, and the NBRCS is used as the reference NBRCS.

In the present embodiment, in the case where the number of intermediate MSBs is one, it is possible to acquire the NBRCS corresponding to the intermediate MSBs and take the NBRCS corresponding to the intermediate MSBs as the reference NBRCS.

Step 502: when the number of intermediate MSBs is plural, an NBRCS mean value of the NBRCS corresponding to the intermediate MSBs is calculated, and the NBRCS mean value is used as the reference NBRCS.

When the number of intermediate MSBs is plural, an NBRCS mean value of the NBRCS corresponding to the intermediate MSBs may be calculated, and the NBRCS mean value may be used as a reference NBRCS.

After determining the reference NBRCS corresponding to the MSBs located within the preset MSB range based on the MSBs located within the preset MSB range and the MSB mean value, step 303 is performed.

Step 303: and determining an NBRCS correction value corresponding to the MSB in a preset MSB range according to the reference NBRCS and the NBRCS corresponding to the MSB in the preset MSB range.

After determining the reference NBRCS corresponding to the MSBs located in the preset MSB range based on the MSBs located in the preset MSB range and the MSB mean value, the NBRCS correction value corresponding to the MSBs located in the preset MSB range may be determined from the reference NBRCS and the NBRCS corresponding to the MSBs located in the preset MSB range. Specifically, an NBRCS difference between the reference NBRCS and the NBRCS corresponding to the MSBs within the preset MSB range may be calculated, and the NBRCS difference may be taken as the NBRCS correction value. This implementation may be described in detail below in conjunction with fig. 6.

Referring to fig. 6, a flowchart of steps of a method for obtaining an NBRCS correction value according to an embodiment of the present application is shown. As shown in fig. 6, the NBRCS correction value acquisition method may include: step 601 and step 602.

Step 601: and calculating to obtain an NBRCS difference value between the reference NBRCS and the NBRCS corresponding to the MSB in the preset MSB range.

In the present embodiment, after obtaining the reference NBRCS, the NBRCS difference between the reference NBRCS and the NBRCS corresponding to the MSBs within the preset MSB range can be calculated.

Step 602: and taking the NBRCS difference value as the NBRCS correction value.

After the NBRCS difference between the reference NBRCS and the NBRCS corresponding to the MSBs within the preset MSB range is calculated, the NBRCS difference may be used as the NBRCS correction value. The NBRCS correction value corresponding to each MSB lying within the preset MSB range can be obtained.

After determining the NBRCS correction value corresponding to the MSB from the MSBs and the corresponding NBRCS within the preset MSB range, step 203 is performed.

Step 203: and establishing the relation mapping model based on the MSB and the corresponding NBRCS correction value within a preset MSB range.

Determining the MSB pair according to the MSB within the preset MSB range and the corresponding NBRCS After the corresponding NBRCS correction values, a relationship map may be established based on the MSB and NBRCS correction values that lie within a preset range. For example, for [10:0.1:20 ]]Each MSB of (where 0.1 is interval, step size range), calculateThe difference between (reference NBRCS) and the NBRCS corresponding to the MSB is the correction value of NBRCS, ++>And (3) establishing a relation mapping model between MSB and NBRCS correction values, wherein the relation mapping model is shown in the following formula (2):

（2）

in the above-mentioned formula (2),for reference NBRCS, < >>NBRCS corresponding to MSB within the preset MSB range, < >>A mapping model of the relationship between MSB and NBRCS correction values may be indicated. The empirical relationship between NBRCS and MSBs can be shown in fig. 14, with the abscissa being the MSB and the ordinate being the NBRCS, and as can be seen from fig. 14, the NBRCS gradually decreases as the MSB increases, so that the NBRCS correction value also increases.

After the target MSB corresponding to the receiver of the target space-based GNSS-R and the target NBRCS corresponding to the target MSB are calculated according to the observation data of the target space-based GNSS-R, it may be first determined whether the target MSB is within the preset MSB range.

If the target MSB is within the preset MSB range, the target NBRCS correction value corresponding to the target MSB may be obtained based on a mapping model based on a relationship between the pre-established MSB and the NBRCS correction value.

After the target NBRCS correction value corresponding to the target MSB is acquired, step 103 is performed.

Step 103: and correcting the target NBRCS based on the target NBRCS correction value to obtain a corrected NBRCS.

After the target NBRCS correction value corresponding to the target MSB is obtained, the target NBRCS may be corrected based on the target NBRCS correction value, to obtain a corrected NBRCS. The correction procedure for NBRCS can be described in detail below in connection with fig. 8.

Referring to fig. 8, a flowchart of steps of a corrected NBRCS acquisition method according to an embodiment of the present application is shown. As shown in fig. 8, the modified NBRCS acquisition method may include: step 801 and step 802.

Step 801: and calculating to obtain NBRCS sum values between the target NBRCS correction value and the target NBRCS.

In the present embodiment, after the target NBRCS correction value is obtained, the NBRCS sum value between the target NBRCS correction value and the target NBRCS may be calculated.

Step 802: the NBRCS sum value is taken as the corrected NBRCS.

After the NBRCS sum value between the target NBRCS correction value and the target NBRCS is calculated, the NBRCS sum value may be used as the corrected NBRCS. The calculation formula is shown in the following formula (3):

（3）

In the above-mentioned formula (3),for target NBRCS, < >>For the corrected NBRCS, +.>Corrected for target NBRCS.

The process of NBRCS correction may be as shown in fig. 13, where the voltage signal received by the antenna is amplified by low noise amplification and then down-converted to intermediate frequency data. The intermediate frequency data is filtered and then reaches the automatic gain control. The automatic gain control automatically adjusts the gain of the automatic gain control according to the voltage of the signal so as to adjust the voltage of the signal. For space-based GNSS-R applications, however, the gain of the automatic gain control is typically a fixed value in order to obtain accurate reflected signal power for scaling. The analog-to-digital converter converts the voltage value of the signal into a digital value with a certain quantization resolution. The digital signal is finally processed by a DDM correlator to obtain a delay-Doppler graph. For sea surface wind speed inversion, the main observed quantity normalized radar cross section coefficient (NBRCS) can be calculated from the delay-Doppler diagram.

After obtaining the observed NBRCS, the observed NBRCS may be corrected based on the NBRCS correction value corresponding to the MSB, thereby obtaining corrected NBRCS. Further, sea surface wind speed can be predicted according to the corrected NBRCS and wind speed inversion model.

According to the embodiment of the application, the relation mapping model between the MSB and the NBRCS correction value is established in advance, so that the correction of any observed quantity NBRCS can be realized, and the observed quantity deviation caused by radio frequency interference can be effectively restrained.

In this embodiment, if the target MSB is not within the preset MSB range, the relationship mapping model may be processed by a linear extrapolation method to obtain a reference NBRCS correction value corresponding to the target MSB, and correct the target NBRCS. This implementation may be described in detail below in conjunction with fig. 9.

Referring to fig. 9, a flowchart of steps of another modified NBRCS acquisition method provided by an embodiment of the present application is shown. As shown in fig. 9, the modified NBRCS acquisition method may include: step 901 and step 902.

Step 901: and under the condition that the target MSB is out of a preset MSB range, processing the relation mapping model based on a linear extrapolation method to obtain a reference NBRCS correction value corresponding to the target MSB.

In this embodiment, linear extrapolation may be used to study things that change at a constant rate of growth over time. In a graph with time as the abscissa, the change of things approaches a straight line. From this line, future changes in things can be inferred.

In the case where the target MSB is out of the preset MSB range, the relation mapping model may be processed based on a linear extrapolation method to obtain a reference NBRCS correction value corresponding to the target MSB. That is, the target MSB and the reference NBRCS correction value corresponding to the target MSB are obtained by means of the outside interpolation based on the MSB indicated in the relational mapping model and the NBRCS corresponding to the MSB.

After obtaining the reference NBRCS correction value corresponding to the target MSB, step 902 is performed.

Step 902: and carrying out correction processing on the target NBRCS based on the reference NBRCS correction value to obtain a corrected NBRCS.

After obtaining the reference NBRCS correction value corresponding to the target MSB, the target NBRCS may be subjected to correction processing based on the reference NBRCS correction value, to obtain a corrected NBRCS. Specifically, the corrected nbrcs=reference nbrcs+target NBRCS.

According to the NBRCS correction method provided by the embodiment of the application, the target MSB corresponding to the receiver of the target space-based GNSS-R and the target NBRCS corresponding to the target MSB are obtained through calculation according to the observation data of the target space-based GNSS-R. And under the condition that the target MSB is in the preset MSB range, acquiring a target NBRCS correction value corresponding to the target MSB based on a relation mapping model between the pre-established MSB and the NBRCS correction value. And correcting the target NBRCS based on the target NBRCS correction value to obtain a corrected NBRCS. According to the embodiment of the application, the relation mapping model between the MSB and the NBRCS correction value is established in advance, so that the correction of any observed quantity NBRCS can be realized, and the observed quantity deviation caused by radio frequency interference can be effectively restrained.

Referring to fig. 15, a schematic structural diagram of an NBRCS correction device according to an embodiment of the present application is shown. As shown in fig. 15, the NBRCS correction apparatus 1500 may include:

a target MSB calculating module 1501, configured to calculate, according to observation data of a target space-based GNSS-R, a target MSB corresponding to a receiver of the target space-based GNSS-R and a target NBRCS corresponding to the target MSB;

a target correction value obtaining module 1502, configured to obtain a target NBRCS correction value corresponding to the target MSB based on a relationship mapping model between a pre-established MSB and an NBRCS correction value when the target MSB is within a preset MSB range;

and an NBRCS correction module 1503, configured to correct the target NBRCS based on the target NBRCS correction value, to obtain a corrected NBRCS.

Optionally, the apparatus further comprises:

Optionally, the NBRCS correction value determining module includes:

Optionally, the reference NBRCS determining unit includes:

Optionally, the reference NBRCS determination subunit includes:

Optionally, the NBRCS correction value determining unit includes:

Optionally, the target MSB calculation module includes:

Optionally, the NBRCS correction module includes:

Optionally, the apparatus further comprises:

According to the NBRCS correction device provided by the embodiment of the application, the target MSB corresponding to the receiver of the target space-based GNSS-R and the target NBRCS corresponding to the target MSB are obtained through calculation according to the observation data of the target space-based GNSS-R. And under the condition that the target MSB is in the preset MSB range, acquiring a target NBRCS correction value corresponding to the target MSB based on a relation mapping model between the pre-established MSB and the NBRCS correction value. And correcting the target NBRCS based on the target NBRCS correction value to obtain a corrected NBRCS. According to the embodiment of the application, the relation mapping model between the MSB and the NBRCS correction value is established in advance, so that the correction of any observed quantity NBRCS can be realized, and the observed quantity deviation caused by radio frequency interference can be effectively restrained.

Additionally, the embodiment of the application also provides electronic equipment, which comprises: the NBRCS correction method comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, wherein the NBRCS correction method is realized when the computer program is executed by the processor.

Fig. 16 shows a schematic structural diagram of an electronic device 1600 according to an embodiment of the present application. As shown in fig. 16, the electronic device 1600 includes a Central Processing Unit (CPU) 1601 that may perform various suitable actions and processes in accordance with computer program instructions stored in a Read Only Memory (ROM) 1602 or loaded from a storage unit 1608 into a Random Access Memory (RAM) 1603. In the RAM1603, various programs and data required for the operation of the electronic device 1600 may also be stored. The CPU1601, ROM1602, and RAM1603 are connected to each other by a bus 1604. An input/output (I/O) interface 1605 is also connected to the bus 1604.

Various components in electronic device 1600 are connected to I/O interface 1605, including: an input unit 1606 such as a keyboard, mouse, microphone, etc.; an output unit 1607 such as various types of displays, speakers, and the like; a storage unit 1608, such as a magnetic disk, an optical disk, or the like; and a communication unit 1609, such as a network card, modem, wireless communication transceiver, or the like. The communication unit 1609 allows the electronic device 1600 to exchange information/data with other devices via a computer network, such as the internet, and/or various telecommunications networks.

The respective procedures and processes described above may be executed by the processing unit 1601. For example, the method of any of the embodiments described above may be implemented as a computer software program tangibly embodied on a computer-readable medium, such as the storage unit 1608. In some embodiments, some or all of the computer programs may be loaded and/or installed onto electronic device 1600 via ROM1602 and/or communication unit 1609. When the computer program is loaded into RAM1603 and executed by CPU1601, one or more acts of the methods described above may be performed.

The embodiment of the application also provides a computer readable storage medium, on which a computer program is stored, which when executed by a processor, realizes the processes of the above-mentioned embodiment of the NBRCS correction method, and can achieve the same technical effects, and in order to avoid repetition, the description is omitted here. Wherein the computer readable storage medium is selected from Read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), magnetic disk or optical disk.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) comprising instructions for causing a terminal (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to perform the method according to the embodiments of the present application.

The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are to be protected by the present application.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a usb disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk, etc.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. A method of NBRCS correction, the method comprising:

correcting the target NBRCS based on the target NBRCS correction value to obtain a corrected NBRCS;

the method further comprises the steps of:

determining a reference NBRCS corresponding to the MSB in a preset MSB range according to the NBRCS corresponding to the middle MSB;

determining an NBRCS correction value corresponding to the MSB in a preset MSB range according to the reference NBRCS and the NBRCS corresponding to the MSB in the preset MSB range;

2. The method of claim 1, wherein determining the reference NBRCS corresponding to the MSBs within a preset MSB range from the NBRCS corresponding to the intermediate MSBs comprises:

3. The method of claim 1, wherein the determining the NBRCS correction value corresponding to the MSB within the preset MSB range from the reference NBRCS and the NBRCS corresponding to the MSB within the preset MSB range comprises:

and taking the NBRCS difference value as the NBRCS correction value.

4. The method according to claim 1, wherein the calculating the target MSB corresponding to the receiver of the target space-based GNSS-R according to the observed data of the target space-based GNSS-R includes:

5. The method of claim 1, wherein the correcting the target NBRCS based on the target NBRCS correction value results in a corrected NBRCS, comprising:

the NBRCS sum value is taken as the corrected NBRCS.

6. The method of claim 1, further comprising, after said calculating a target MSB corresponding to a receiver of said target space-based GNSS-R and a target NBRCS corresponding to said target MSB:

7. An NBRCS correction device, the device comprising:

the NBRCS correction module is used for correcting the target NBRCS based on the target NBRCS correction value to obtain a corrected NBRCS;

the apparatus further comprises:

a relation mapping model establishing module, configured to establish the relation mapping model based on the MSBs within a preset MSB range and the corresponding NBRCS correction values;

the NBRCS correction value determination module includes:

an NBRCS correction value determining unit configured to determine an NBRCS correction value corresponding to the MSB located within a preset MSB range according to the reference NBRCS and an NBRCS corresponding to the MSB located within the preset MSB range;

the reference NBRCS determination unit includes:

8. The apparatus of claim 7, wherein the reference NBRCS determination subunit comprises:

9. The apparatus according to claim 7, wherein the NBRCS correction value determining unit includes:

and the NBRCS correction value acquisition subunit is used for taking the NBRCS difference value as the NBRCS correction value.

10. The apparatus of claim 7, wherein the target MSB computation module comprises:

11. The apparatus of claim 7, wherein the NBRCS correction module comprises:

12. The apparatus of claim 7, wherein the apparatus further comprises:

13. An electronic device, comprising:

memory, a processor and a computer program stored on the memory and executable on the processor, which when executed by the processor implements the NBRCS correction method according to any one of claims 1 to 6.

14. A readable storage medium, characterized in that instructions in the storage medium, when executed by a processor of an electronic device, enable the electronic device to perform the NBRCS correction method of any one of claims 1 to 6.