CN210199331U - Receiver of foundation microwave radiometer system and foundation microwave radiometer system - Google Patents

Abstract

The utility model discloses a receiver and ground microwave radiometer system of ground microwave radiometer system, the receiver includes: a feed source horn; a low noise amplifier; a refrigeration absorption load; and the microwave selection switch is used for transmitting the bright temperature signal of the feed source horn to the low-noise amplifier or transmitting the bright temperature signal of the refrigeration absorption load to the low-noise amplifier. The utility model discloses a high temperature black body and refrigeration absorption load carry out the calibration as two point calibration sources, replace two point calibration of traditional outside normal atmospheric temperature calibration source and receiver internal switch noise source, need not high accuracy control by temperature change and regular outside calibration, also can obtain the calibration of high accuracy.

Description

Receiver of foundation microwave radiometer system and foundation microwave radiometer system

Technical Field

The utility model relates to a microwave remote sensing, microwave guidance and precision measurement field especially relate to a receiver and ground microwave radiometer system of ground microwave radiometer system.

Background

The ground-based microwave radiometer for the weather is a means for the meteorological observation, and has been researched, manufactured and put into the weather prediction by many countries at home and abroad. Fig. 1 is a schematic block diagram of a conventional ground-based microwave radiometer, and since the ground-based microwave radiometer is a linear system, a straight-line theory is determined by two points, and the radiometer needs two calibration sources as reference points for calibration during operation, the calibration method at present uses an external normal-temperature black body (normal-temperature/low-temperature calibration source) and a receiver internal switching noise source (high-temperature calibration source) as two point calibration sources for calibration. This calibration method has the following problems:

1) the noise source is an active signal generating device, the stability of the noise source is greatly influenced by temperature, and high-precision temperature control needs to be carried out on the noise source;

2) the performance of the noise source changes along with time, the noise source needs to be calibrated externally at regular intervals (half a year or one year), liquid nitrogen is used for external calibration, the operation is troublesome, and some places cannot obtain the liquid nitrogen.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention provides a receiver of a ground-based microwave radiometer system and a ground-based microwave radiometer system, which can obtain high-precision calibration without high-precision temperature control and periodic external calibration.

In order to achieve the above purpose, the technical scheme of the utility model is as follows:

the utility model provides a receiver of ground based microwave radiometer system, the receiver includes: a feed source horn;

a low noise amplifier;

a refrigeration absorption load;

and the microwave selection switch is used for transmitting the bright temperature signal of the feed source horn to the low-noise amplifier or transmitting the bright temperature signal of the refrigeration absorption load to the low-noise amplifier.

Preferably, the microwave selection switch is a waveguide switch.

Preferably, the waveguide switch is an electromechanical waveguide switch.

Through the technical scheme, the utility model discloses a receiver and ground microwave radiometer system of ground microwave radiometer system, through high temperature black body and refrigeration absorption load as two point calibration sources and scale, replace two point calibration of traditional outside normal atmospheric temperature calibration source and receiver internal switch noise source, need not high accuracy control by temperature change and regular outside calibration, also can obtain the calibration of high accuracy.

Drawings

FIG. 1 is a schematic diagram of a prior art ground-based microwave radiometer system;

fig. 2 is a schematic structural diagram of a microwave radiometer system for foundation according to an embodiment of the present invention;

fig. 3 is a schematic diagram of an operating state diagram of a waveguide switch in a microwave radiometer system according to an embodiment of the present invention;

fig. 4 is a schematic diagram illustrating another operating state of a waveguide switch in a microwave radiometer system according to an embodiment of the present invention;

fig. 5 is a schematic flow chart of a calibration method of the microwave radiometer system according to an embodiment of the present invention.

Detailed Description

The embodiment of the utility model provides a receiver of ground based microwave radiometer system, the receiver includes:

a feed source horn;

a low noise amplifier;

a refrigeration absorption load;

and the microwave selection switch is used for transmitting the bright temperature signal of the feed source horn to the low-noise amplifier or transmitting the bright temperature signal of the refrigeration absorption load to the low-noise amplifier.

The embodiment of the utility model provides a still provide a ground microwave radiometer system, the system includes:

a black body of a preset temperature;

the receiver described above;

and conducting the bright temperature signal of the black body to a parabolic antenna of the receiver.

The utility model discloses principle of embodiment: the high-temperature black body and the refrigeration absorption load are used as two-point calibration sources for calibration, the two-point calibration of the traditional external normal-temperature calibration source and the internal switching noise source of the receiver is replaced, the high-temperature black body is high in stability, performance change can not occur along with time, high-precision temperature control and regular external calibration are not needed, and high-precision calibration can be obtained.

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

Example one

As shown in fig. 2, an embodiment of the present invention provides a ground-based microwave radiometer system, which includes:

a receiver 11;

a black body of a preset temperature;

the bright temperature signal of the black body is conducted to the parabolic antenna 31 of the receiver.

Wherein, the preset temperature of the black body is as follows: 100-150 ℃, which is generally called as a high temperature black body 21. Thus, the bright temperature performance of the black body is more stable and does not change with time, which is a preferred mode.

Wherein the receiver 11 comprises:

a feed horn 111;

a low noise amplifier 112;

a refrigeration absorption load 113;

and a microwave selection switch 114 for conducting the bright temperature signal of the feed horn to the low noise amplifier or conducting the bright temperature signal of the refrigeration absorption load to the low noise amplifier. In this way, the receiver 11 can receive the brightness temperature signal of the high temperature black body 21 as one of the calibration sources through the feed horn 111 and the low noise amplifier 112, and can also receive the brightness temperature signal of the cooling absorption load 113 as the second of the calibration sources through the low noise amplifier 112, so that the two-point calibration of the conventional external normal temperature calibration source and the receiver internal switching noise source can be replaced, which is a preferable mode.

Wherein the microwave selection switch 114 is a waveguide switch. The waveguide switch is selected, has the characteristics of low standing wave, small insertion loss and large power capacity, is a preferred mode, and can be other selective switches as can be understood by a person skilled in the art. Fig. 3 and 4 show two working states of the waveguide switch, where fig. 3 shows that the receiver 11 receives the bright temperature signal of the high temperature black body 21 through the feed horn 111 and the low noise amplifier 112, and fig. 4 shows that the receiver 11 receives the bright temperature signal of the refrigeration absorbing load 113 through the low noise amplifier 112.

The waveguide switch is an electromechanical waveguide switch, and the electromechanical waveguide switch has the advantages of simple structure and low cost and is a preferred mode; it will be appreciated that other waveguide switches are possible, for example ferrite waveguide switches.

Example two

As shown in fig. 5, an embodiment of the present invention further provides a calibration method for a ground-based microwave radiometer system, where the method includes:

step 501: the refrigeration absorbing load 113 is externally scaled. The method specifically comprises the following steps:

respectively placing a cold calibration source and a normal-temperature calibration source at the parabolic antenna 31 to test the foundation microwave radiometer;

obtaining the equivalent brightness temperature of the high-temperature black body 21 and the refrigeration absorption load 113 according to the test result;

and performing external calibration on the refrigeration absorbing load 113 according to the equivalent bright temperature.

Since there is a certain loss in the refrigeration absorbing load 113 due to the waveguide switch switching, external calibration is required, but the external calibration is only required once before shipment and is not required again thereafter.

The cold calibration source in the external calibration is liquid nitrogen, and the normal-temperature calibration source is a normal-temperature black body, namely the temperature of the black body is 20-25 ℃.

Step 502: a first output voltage of the high temperature black body 21 is obtained. The method specifically comprises the following steps:

and the bright temperature signal of the feed source horn is conducted to the low-noise amplifier through the microwave selection switch.

The black body with the preset temperature is the high-temperature black body, and the bright temperature signal of the high-temperature black body is conducted to the feed source loudspeaker through the parabolic antenna and then conducted to the receiver through the feed source loudspeaker.

Step 503: and acquiring a second output voltage of the refrigeration absorption load. The method specifically comprises the following steps:

the microwave selection switch 114 is used to conduct the bright temperature signal of the refrigeration absorption load 113 to the low noise amplifier 112.

Step 504: and calibrating the ground-based microwave radiometer system according to the first output voltage and the second output voltage.

The calibration method of the foundation microwave radiometer system of the embodiment switches the absorption load of the low noise amplifier as a normal temperature calibration source through the microwave selection switch, and realizes two-point calibration by matching with a high temperature black body as a high temperature calibration source. The two-point calibration scheme can realize real-time calibration without regular external calibration, and the high-temperature black body has better long-term stability of the brightness temperature and cannot change the performance along with the time change, so that the performance of the foundation microwave radiometer system is more stable.

The above-mentioned embodiments further explain the technical problems, technical solutions and advantages of the present invention in detail, it should be understood that the above-mentioned embodiments are only examples of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (5)

1. A receiver of a ground-based microwave radiometer system, comprising:

a feed source horn;

a low noise amplifier;

a refrigeration absorption load;

and the microwave selection switch is used for transmitting the bright temperature signal of the feed source horn to the low-noise amplifier or transmitting the bright temperature signal of the refrigeration absorption load to the low-noise amplifier.

2. The receiver of a ground-based microwave radiometer system of claim 1, wherein the microwave selection switch is a waveguide switch.

3. The receiver of claim 2, wherein the waveguide switch is an electromechanical waveguide switch.

4. A ground-based microwave radiometer system, comprising:

a receiver as claimed in any one of claims 1 to 3;

a black body of a preset temperature;

and conducting the bright temperature signal of the black body to a parabolic antenna of the receiver.

5. The ground-based microwave radiometer system of claim 4, wherein the preset temperature of the black body is: 100 to 150 ℃.

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