Method for controlling satellite-borne same-frequency-band active and passive loads to avoid interference time division work

Abstract

The invention provides a method for controlling satellite-borne same-frequency-band active and passive loads to avoid interference time division work. The method comprises the steps that a cooperative work control unit is adopted to generate and send synchronous pulse signals to the satellite-borne active load and the satellite-borne passive load; the high and low levels of the synchronous pulse signal correspond to the working time periods of the two types of loads, and the working time sequence of the active load and the passive load is controlled; and the active load and the passive load perform pulse edge detection after receiving the synchronization pulse signal, and work in the corresponding level duration. According to the method, periodic pulses are used for commanding and controlling the power transmitting time of the active load, so that the passive load is prevented from receiving signals during the working period of the microwave scatterometer, and the active load is prevented from influencing the passive load; active and passive loads of the same frequency band are integrated under the condition of limited satellite platform resources, mutual interference of each other is avoided, and meanwhile high-precision detection is obtained.

Description

Technical Field

[0001] The invention belongs to the field of active and passive combined remote sensing technology in the field of satellite remote sensing, and particularly relates to a method for controlling satellite-borne active and passive loads in the same frequency band to work in time-division manner to avoid interference. Background Art

[0002] The difficulty of satellite microwave remote sensing detection technology lies in the fact that the detection elements of interest are usually affected by multivariate factors. Therefore, it is necessary to observe multiple variables at the same time to reduce the impact of the spatiotemporal changes of the observed elements on the detection accuracy. When a microwave remote sensing satellite carries both an active transmitting power payload and a passive high-sensitivity receiving payload, and they operate in the same frequency band, the electromagnetic compatibility between the active and passive payloads becomes one of the key factors affecting the payload detection accuracy performance. How to control the active and passive payloads in the same frequency band to work autonomously in orbit without interfering with each other has become a technical difficulty that needs to be solved. Summary of the invention

[0003] In order to overcome the deficiencies in the prior art, the inventors have conducted intensive research and provided a method for controlling the time-sharing operation of active and passive payloads in the same frequency band on board a satellite to avoid interference, and a method for using periodic pulses to command and control the transmission power time of active payloads such as microwave scatterometers, so that passive payloads such as microwave radiometers can avoid receiving signals during the operation of the microwave scatterometers, so as to avoid the microwave scatterometers affecting systems such as microwave radiometers; the method has scalability and compatibility, and can be used for the synchronous operation of active and passive microwave remote sensing payloads of the same system but different system parameters.

[0004] The technical solution provided by the present invention is as follows:

[0005] A method for controlling the interference-avoiding time-division operation of active and passive payloads on board the satellite in the same frequency band, comprising: using a collaborative work control unit to generate and send a synchronization pulse signal to the active and passive payloads on board the satellite; the high and low levels of the synchronization pulse signal correspond to the working periods of the two types of payloads, and the working sequence of the active and passive payloads is controlled;

[0006] After receiving the synchronous pulse signal, the active load and the passive load perform pulse edge detection and work within the corresponding level duration period.

[0007] A method for controlling the interference-avoiding time-division operation of active and passive payloads in the same frequency band on board a satellite provided by the present invention has the following beneficial effects:

[0008] The present invention provides a method for controlling satellite-borne active and passive payloads in the same frequency band to avoid interference and work in time division. In a satellite system in which active and passive payloads observe in the same direction, a time sequence scheduling method for coordinated work is adopted. The high and low levels of a synchronous pulse signal correspond to the control of the active and passive payloads. After receiving the pulse, the active and passive payloads perform pulse edge detection and work within the duration of the corresponding level, that is, during the time when the microwave scatterometer transmits power, so that the microwave radiometer avoids receiving signals during the operation of the microwave scatterometer, so as to avoid the microwave scatterometer affecting the microwave radiometer and other systems. While ensuring that the two work in the same direction, their respective performances can be maintained, so as to realize a method for integrating active and passive payloads in the same frequency band to avoid interference from each other and simultaneously obtain high-precision detection under limited satellite platform resources. For example, it can be applied to the field of high-precision ocean salinity detection, so as to realize satellite-borne high-sensitivity, high-resolution and high-precision ocean salinity detection, and the microwave radiometer and the microwave scatterometer synchronously obtain brightness temperature detection data and various auxiliary data on orbit, so as to realize high-precision ocean salinity detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the synchronous pulse connection between the collaborative working control unit and the active load and passive load;

[0010] Figure 2 This is a flow chart of a method for controlling the satellite-borne active and passive loads in the same frequency band to avoid interference and work in time division according to the present invention;

[0011] Figure 3 It is the normal working timing of the synchronization pulse;

[0012] Figure 4 This is the working strategy when the synchronization pulse fails. DETAILED DESCRIPTION

[0013] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0014] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0015] The present invention provides a method for controlling the active and passive loads on board the satellite to avoid interference and work in time division. Figure 1 As shown, the following steps are included:

[0016] A collaborative working control unit is used to generate and send synchronization pulse signals to active payloads such as microwave scatterometers and passive payloads such as microwave radiometers on board the satellite; the high and low levels of the synchronization pulse signals correspond to the working time periods of the active payloads such as microwave scatterometers and passive payloads such as microwave radiometers, and the synchronization pulse signals respectively control the working timings of the active payloads such as microwave scatterometers and passive payloads such as microwave radiometers.

[0017] After receiving the synchronous pulse signal, the active load and the passive load perform pulse edge detection and operate during the corresponding level duration period. For example, within each T0 working cycle, the pulse emission duration of the active load is not greater than T1, and the working duration of the passive load is not greater than T2, where T0 = T1 + T2. In the synchronous working protocol of the active load and the passive load, the corresponding levels for starting the operation of the active load and the passive load, the preset working duration after each start, and the operation rules during faults are specified. For example, when the level is low, the active load such as a microwave scatterometer operates, and when the level is high, the passive load such as a microwave radiometer operates.

[0018] The method of the present invention involves the following aspects: the working process when the synchronous pulse signal is normal, the processing process when the synchronous pulse signal fails, and the design of the synchronous pulse interface.

[0019] (1) The working process when the synchronous pulse signal is normal, see Figure 2 .

[0020] The normal working mode of the synchronous pulse signal controls the operation of the active load and the passive load based on high and low levels respectively. The low-level duration is defined as T1, and the high-level duration is defined as T2. When the level is low, the active load emits a signal, and when the level is high, the passive load operates, T1 < T2; of course, it can also be that when the level is high, the active load emits a signal, and when the level is low, the passive load operates, and the working durations of the active load and the passive load are determined according to needs. The clock pulse width of the RS422 differential voltage signal as the synchronous pulse signal has an error from the nominal value < T1 / 1000.

[0021] When the level is low, the active load emits a signal, and when the level is high, the passive load operates. After receiving the synchronous pulse signal, each active and passive load first determines whether the synchronous pulse signal is normal. If normal, after receiving the synchronous pulse signal, each active and passive load performs pulse edge detection; when the falling edge is detected, the active load starts to emit a signal after a protection time of Δ1 主 and ends the signal emission before a time of Δ1 主 from the rising edge. The signal emission duration of the active load is T1 - 2Δ1 主 ; when the rising edge is detected, the passive load starts to operate after a protection time of Δ1 被 and ends the operation before a time of Δ1 被 from the falling edge. The working duration of the passive load is T2 - 2Δ1 被 ; Δ1 主 and Δ1 被 are the protection bands for the start-up working interval time of the active and passive loads respectively. The active and passive loads on orbit strictly operate according to the command of the synchronous pulse signal, see Figure 3 .

[0022] (2) Processing flow in case of synchronous pulse signal failure, see Figure 2 .

[0023] When the active and passive loads receive the synchronous pulse signal, they align their working cycles with their own timers and start timing. If it is found that the synchronous pulse can be detected but the period does not match the set period or the synchronous pulse cannot be detected, it is considered that the synchronous pulse signal fails at this time. When a synchronous pulse signal failure is detected, each active and passive load marks the synchronous pulse as abnormal in the engineering parameters, feeds back the abnormal information to the collaborative work control unit, and the collaborative work control unit uniformly determines whether there is an abnormality at the source end (the synchronous pulse interface of the collaborative work control unit) or the receiving end (the synchronous pulse interface of the active and passive loads) of the synchronous pulse signal.

[0024] (i) If the synchronous pulse cannot be detected (the signal remains at a low level or a high level) and the source end is abnormal, it is required that the collaborative work control unit restart the synchronous pulse generation circuit. During this period, the signal transmission of the active load and the operation of the passive load (start-up and operation duration after start-up) are still strictly controlled by the synchronous pulse timing, that is, the active load or the passive load starts according to the detected pulse edge and works according to the normal operation duration T1 - 2Δ1 主 or T2 - 2Δ1 被 and work.

[0025] (ii) If the synchronous pulse cannot be detected (the signal remains at a low level or a high level) and the receiving end is abnormal, the collaborative work control unit controls the receiving end to restart and receive the synchronous pulse again.

[0026] (iii) In the fault mode where the duration of the synchronous pulse signal level is disordered (source end abnormality), that is, the low-level duration ≠ T1, it is divided into two cases:

[0027] When the low-level duration T3 < T1, the active load must stop transmitting the signal within ≤ Δ2 time after detecting the rising edge of the next passive load. The passive load starts to work after a protection time of Δ1 被 to ensure that the passive load is not interfered by the active load, see 被 ; Figure 4 ;

[0028] When the low-level duration T3 > T1, the active load can still transmit the signal according to the normal working process of the synchronous pulse, that is, after the active load detects the falling edge, it starts to transmit the signal after a protection time of Δ1 主 and stops transmitting the signal after working according to the normal working duration (T1 - 2Δ1 主 ); the passive load starts to work after a protection time of Δ1 被 after detecting its corresponding rising edge and ends the work when detecting the falling edge of the next corresponding active load.

[0029] (3) Synchronous pulse interface design

[0030] The synchronous pulse interface of the source and receiving ends adopts the standard RS422 driving circuit for synchronous pulse interface design. The synchronous pulse interface of the cooperative control unit generates RS422 differential voltage signal as the synchronous pulse signal, which is received by the synchronous pulse interface of active loads such as microwave scatterometers and passive loads such as microwave radiometers as the reference for the working timing of these devices. The pulse width and edge requirements must meet the general standard of RS422 differential voltage signal.

[0031] The synchronous pulse interface of the source end and the receiving end adopts the same type of RS422 driving circuit and interface chip from the same manufacturer, and the active load and passive load interface chips store the synchronous working protocol of the active load and the passive load.

[0032] In addition to the above-mentioned RS422 interface circuit, as long as the interface circuits implementing the method of the present invention are within the protection range, different on-board payloads can select different time parameters.

[0033] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0034] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for controlling the active and passive payloads on board the same frequency band to avoid interference and work in time division, characterized in that: include: A collaborative control unit is used to generate and send synchronous pulse signals to active and passive payloads on board the satellite; The high and low levels of the synchronization pulse signal correspond to the working periods of the two types of loads, and control the working sequence of the active load and the passive load; After receiving the synchronous pulse signal, the active load and the passive load perform pulse edge detection and work within the corresponding level duration period.

2. The method for controlling the satellite-borne active and passive loads in the same frequency band to avoid interference and work in time division according to claim 1, characterized in that: The steps of performing pulse edge detection on the active load and the passive load after receiving the synchronous pulse signal and working within the corresponding level duration period include: After receiving the synchronization pulse signal, the active load and the passive load determine whether the synchronization pulse signal is normal. If normal, each active and passive load performs pulse edge detection after receiving the synchronization pulse signal. After the active load detects its corresponding pulse edge, it 主 The signal starts to be transmitted after the protection time, and the signal is transmitted Δ1 before the pulse edge corresponding to the next passive load. 主 Time end signal emission; After the passive load detects its corresponding pulse edge, it 被 The protection time starts to work and the next active load corresponding pulse edge is Δ1 被 Time to finish work; Δ1 主 and Δ1 被 They are respectively the startup working interval protection bands of the active and passive loads.

3. The method for controlling the satellite-borne active and passive loads in the same frequency band to avoid interference and work in time division according to claim 2, characterized in that: The step of determining whether the synchronization pulse signal is normal after the active load and the passive load receive the synchronization pulse signal comprises: after receiving the synchronization pulse signal, the active and passive loads align the working cycle with their own timers and perform timing. If it is found that the synchronization pulse can be detected but the cycle does not match the set cycle or the synchronization pulse cannot be detected, it is considered that the synchronization pulse signal is faulty at this time; when a synchronization pulse signal fault is found, each active and passive load marks the synchronization pulse abnormality in the engineering parameters, feeds back the abnormal information to the collaborative work control unit, and the collaborative work control unit determines whether the synchronization pulse signal has a source end or a receiving end abnormality.

4. The method for controlling the satellite-borne active and passive loads in the same frequency band to avoid interference and work in time division according to claim 3, characterized in that: When the active load and the passive load cannot detect the synchronization pulse and the source end is abnormal, the collaborative control unit restarts its synchronization pulse interface. During the restart period, the active load transmission signal and the passive load operation are still controlled by the synchronization pulse timing.

5. The method for controlling the satellite-borne active and passive loads in the same frequency band to avoid interference and work in time division according to claim 3, characterized in that: When the active load and the passive load cannot detect the synchronization pulse and the receiving end is abnormal, the collaborative control unit controls the active load and the passive load synchronization pulse interface to restart and receive the synchronization pulse again.

6. The method for controlling the satellite-borne active and passive loads in the same frequency band to avoid interference and work in time division according to claim 3, characterized in that: In the fault mode of disordered level duration of synchronous pulse signal, there are two cases: when the level duration T3 corresponding to the active load is less than the preset level duration T1, the active load shall stop transmitting the signal within Δ2 time after detecting the next passive load pulse edge, and the passive load shall stop transmitting the signal within Δ1 time after the passive load pulse edge. 被 Start working after time, and Δ2<Δ1 被 ; When the level duration T3 corresponding to the active load is greater than the preset level duration T1, the active load transmits the signal according to the normal working process of the synchronous pulse signal; after the passive load detects its corresponding pulse edge, it transmits the signal after a period of Δ1 被 It starts working after the protection time and ends working when the falling edge corresponding to the next active load is detected.

7. The method for controlling the satellite-borne active and passive loads in the same frequency band to avoid interference and work in time division according to claim 1, characterized in that: The collaborative work control unit generates a synchronization pulse signal through a synchronization pulse interface; the active load and the passive load receive the synchronization pulse signal through the synchronization pulse interface; the synchronization pulse interfaces of the collaborative work control unit, the active load and the passive load all adopt RS422 drive circuit and interface chip design, and the active load and passive load interface chips store the synchronization work protocol of the active load and the passive load.

8. The method for controlling the satellite-borne active and passive loads in the same frequency band to avoid interference and work in time division according to claim 7, characterized in that: The synchronous pulse interface of the cooperative working control unit generates an RS422 differential voltage signal as a synchronous pulse signal.

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