CN210109362U

CN210109362U - Real-time calibration foundation radiometer

Info

Publication number: CN210109362U
Application number: CN201920825804.3U
Authority: CN
Inventors: 童海明; 任海元; 王景桦; 郭臣; 王雷
Original assignee: Hangzhou Shallow Sea Science And Technology Co Ltd
Current assignee: Hangzhou Shallow Sea Science And Technology Co Ltd
Priority date: 2019-06-03
Filing date: 2019-06-03
Publication date: 2020-02-21
Anticipated expiration: 2029-06-03

Abstract

The utility model provides a ground radiometer of real-time calibration, central processing circuit integrated circuit board including the host computer, with the host computer connection, step motor and the receiver of being connected with central processing circuit board card, step motor is connected with parabolic antenna, the receiver is connected with feed loudspeaker, a serial communication port, the receiver is formed by switching noise source, low noise amplifier, merit divider connection. The utility model discloses a switch switching band low noise amplifier's absorption load is as normal atmospheric temperature calibration source, and the cooperation switch noise source realizes two interior calibrations of point as high temperature calibration source, when realizing real-time calibration, can not make ground radiometer noise properties worsen.

Description

Real-time calibration foundation radiometer

Technical Field

The utility model relates to a ground microwave radiometer field, in particular to ground radiometer of real-time calibration and calibration method thereof.

Background

The ground microwave radiometer is ground microwave remote sensing equipment which utilizes microwave signals of atmospheric radiation transmitted from various heights to judge atmospheric temperature and humidity changes, and has an important detection function on medium and small-scale weather phenomena such as rainstorm, lightning, heavy rainfall, fog, freezing and boundary layer turbulence. The research of temperature, humidity and liquid water of a troposphere section, weather and climate models of a foundation microwave radiometer, satellite tracking (GPS, Galileo) wet/dry delay and humidity profiles, near forecast atmospheric stability (disastrous weather detection), temperature inversion detection, fog and air pollution, absolute calibration of a cloud radar and wet/dry delay correction VLBI have important application and become an important detection means outside a sounding balloon and a weather radar. The ground-based microwave radiometer has independent working capacity, can work under almost various environmental conditions, is suitable for an automatic weather station, is commonly used for inverting a complete atmospheric profile, and completely stores inverted data and original data.

FIG. 1 is a schematic block diagram of a ground-based radiometer, which realizes the calibration of the radiometer by the antenna observation of a normal temperature calibration source in cooperation with the switching of a switching noise source. Because the ground radiometer is a linear system, a straight line theory is determined through two points, two calibration source reference points are needed for the work of the radiometer, the traditional temperature and humidity profile ground radiometer uses an external absorption material as a normal-temperature calibration source and is matched with a switch noise source inside a receiver to realize two-point calibration (figure 1), later, in order to realize real-time internal calibration of the radiometer, a switch isolator is added inside the receiver by an RPG company, and the calibration of the radiometer system is realized through a two-point internal calibration mode of the switch noise source and the switch isolator (figure 2).

The main bottlenecks of the traditional ground radiometer calibration mode are:

for a calibration scheme that an external blackbody calibration source is matched with a receiver internal switch noise source, the calibration scheme needs to be calibrated by rotating an antenna to a specified position, and real-time calibration cannot be carried out;

the two-point internal calibration scheme of the switch isolator and the switch noise source of the RPG company solves the real-time calibration problem, but the current scheme is based on the switch isolator self-developed by the RPG company as the technical basis, the switch isolator technology is only mastered by the RPG company at present, and the technical monopoly belongs to the technical monopoly;

the addition of a two-point calibration scheme by RPG corporation to a switched isolator can degrade radiometer noise performance to some extent.

SUMMERY OF THE UTILITY MODEL

Technical problem to be solved

To solve the above problem, the utility model provides a ground radiometer of real-time calibration and its calibration method.

(II) technical scheme

The utility model provides a ground radiometer of real-time calibration, includes the host computer, with the central processing circuit integrated circuit board of host computer connection, step motor and the receiver of being connected with central processing circuit board card, step motor is connected with parabolic antenna, the receiver is connected with feed loudspeaker, the receiver is formed by switching noise source, absorption load, low noise amplifier, switch module and merit divider connection, switch module switches between absorption load and switching noise source.

Furthermore, the common end of the switch module is connected with a low noise amplifier, the two ends of the other side of the switch module are respectively connected with a switch noise source and an absorption load, the low noise amplifier is connected with the power divider, and the switch noise source is connected with the feed source horn.

Furthermore, the common end of the switch module is connected with the power divider, the two ends of the other side are respectively connected with a switch noise source and an absorption load, and low noise amplifiers are arranged between the switch noise source and the absorption load and the switch module.

The calibration method specifically comprises the following steps: placing liquid nitrogen and a normal-temperature black body on the antenna opening surface of the radiometer before leaving a factory, carrying out external calibration on the radiometer, testing to obtain the equivalent bright temperature of the noise injection state of a switching noise source and carrying out two-point calibration by switching the switching on of the switch to the equivalent bright temperature of an absorption load channel; and entering a working state, and performing real-time two-point calibration on the radiometer by using the switching noise source and the absorption load obtained by the test as a calibration source.

(III) advantageous effects

1. The technical monopoly of the switch isolator is broken;

2. because the electronic switch is switched to realize calibration, the real-time calibration of the foundation radiometer can be realized;

3. additional noise is not introduced to deteriorate the noise performance of the ground-based radiometer.

Drawings

FIG. 1 is a schematic diagram of the prior art;

FIG. 2 is a schematic block diagram of a RPG corporation ground-based radiometer;

fig. 3 is a schematic diagram of an embodiment of the present invention;

fig. 4 is a schematic diagram of another embodiment of the present invention.

Detailed Description

The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

Example 1

Referring to fig. 3, a real-time calibration ground radiometer comprises an upper computer, a central processing circuit board card connected with the upper computer, a stepping motor connected with the central processing circuit board card, and a receiver, wherein the stepping motor is connected with a parabolic antenna, the receiver is connected with a feed horn, the receiver is formed by connecting a switch noise source, an absorption load, a low noise amplifier, a switch module and a power divider, the common end of the switch module is connected with the low noise amplifier, two ends of the other side are respectively connected with the switch noise source and the absorption load, the low noise amplifier is connected with the power divider, and the switch noise source is connected with the feed horn.

Example 2

Referring to fig. 4, a real-time calibration foundation radiometer comprises an upper computer, a central processing circuit board card connected with the upper computer, a stepping motor connected with the central processing circuit board card, and a receiver, wherein the stepping motor is connected with a parabolic antenna, the receiver is connected with a feed source horn, the receiver is formed by connecting a switching noise source, an absorption load, a low noise amplifier, a switching module and a power divider, the switching module is arranged between the low noise amplifier and the power divider, the common end of the switching module is connected with the power divider, two ends of the other side are respectively connected with the switching noise source and the absorption load, the low noise amplifier is arranged between the switching module and the switching noise source, and the low noise amplifier is arranged between the switching module and the absorption load.

In order to ensure the consistency of the system, a first-level low noise amplifier is added in the absorption load and the switch module, so that the normal-temperature calibration of the system is realized on the premise of not influencing the noise performance, and the two-point internal calibration is realized by matching with a switch noise source.

The utility model discloses two interior calibration schemes of point pass through the switch switching band low noise amplifier's absorption load as normal atmospheric temperature calibration source, and the cooperation switch noise source realizes two interior calibrations of point as the high temperature calibration source. Novel two point scaling schemes can realize real-time scaling, and can not make ground radiometer noise performance worsen, the utility model discloses the result that scaling method and current scaling method performance are compared is shown as the following table.

Index name	Calibration period (minutes)	Noise degradation (dB)
			Traditional normal temperature external calibration + switch noise source	>5	Is free of
RPG company switch isolator + switch noise source	<1	0.5
			Novel two-point internal calibration scheme	<1	Is free of

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the technical principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The utility model provides a ground radiometer of real-time calibration, includes the host computer, with the central processing circuit integrated circuit board of host computer connection, step motor and the receiver of being connected with central processing circuit board card, step motor is connected with parabolic antenna, the receiver is connected with feed loudspeaker, its characterized in that, the receiver is connected by the switching noise source, absorption load, low noise amplifier, switch module and merit and forms, switch module can switch between absorption load and switching noise source.

2. The real-time scaled ground-based radiometer of claim 1, wherein: the common end of the switch module is connected with a low noise amplifier, the two ends of the other side of the switch module are respectively connected with a switch noise source and an absorption load, the low noise amplifier is connected with the power divider, and the switch noise source is connected with the feed source horn.

3. The real-time scaled ground-based radiometer of claim 1, wherein: the common end of the switch module is connected with the power divider, the two ends of the other side are respectively connected with a switch noise source and an absorption load, and low-noise amplifiers are arranged between the switch noise source and the absorption load and the switch module.