CN106226269A - A kind of high accuracy air refraction is measured indirectly, wireless transmission system and method thereof - Google Patents

Abstract

The invention discloses a kind of high accuracy air refraction indirectly measure, wireless transmission system, including humiture and barometric pressure sensor, main control chip, power amplifier chip, impedance matching circuit, antenna radiating circuit and coordinator.Main control chip controls humiture and barometric pressure sensor collecting temperature, humidity and atmospheric pressure information, and main control chip processes the value calculating air refraction to these information, and by making user obtain the value of this air refraction after wireless transmission and reception.Utilize said system realize high accuracy air refraction indirectly measure, wireless transmission, surveyed ambient parameter can be utilized accurately to calculate the value of air refraction, thus solve existing air and penetrate the problem that rate measurement apparatus structure is complicated, volume is big, be inconvenient to carry, present system simple in construction easily realizes, as a kind of wireless sensing node, on-the-spot atmospheric parameter can be measured in real time, and be wirelessly sent to the computer terminal that coordinator connected and process.

Description

A kind of high accuracy air refraction is measured indirectly, wireless transmission system and method thereof

Technical field

The present invention relates to a kind of high accuracy air refraction indirect measurement systems and method.

Background technology

The refractive index of medium is one of physical quantity characterizing Medium Optics characteristic.Air refraction has with temperature and pressure Close, can change with air condition, and this parameter is in a lot of field of scientific studies, such as high temp objects environment temperature field distribution Measuring, tunnel airstream pattern is drawn, the aerodynamics analysis etc. of aircraft has application, only air refraction is approximately 1 Can not meet far away the requirement of scientific research, so the accurate measurement method of research air refraction is the most necessary.

In field of measuring technique, high-precision absolute distance measurement technology can improve main equipment, scientific instrument The level manufacturing, assembling, the level for science of promoting technological progress, improve has important meaning.

And in high-precision absolute distance measurement, the impact of real-Time Compensation air refraction is necessary.Existing Some air refractions are measured and are generally used optical instrument directly to record, the construction features being had due to optics, its structure The measurement apparatus become also exists structure complexity, volume big (such as degassing method, Rayleigh interferometric method, F-P beat frequency method), experiment condition Require that the method precision that harsh (interferometry as double in corrugated tube), device are difficult to demarcate (such as trapezoidal vacuum cell method), have is inadequate Shortcomings such as (such as total reflection phase hit methods).And various measurement apparatus is all difficult to portable structure, it is difficult to measurement result It is modified in real time.

Summary of the invention

For prior art, the present invention provides a kind of high accuracy air refraction indirectly to measure, wireless transmission system and survey Metering method, solves existing air and penetrates that rate measurement apparatus structure is complicated, volume big, is inconvenient to the problem carried, and the present invention is System simple in construction easily realizes, and can measure on-the-spot atmospheric parameter in real time as a kind of wireless sensing node, and wireless Give the computer terminal that coordinator connected to process.

In order to solve above-mentioned technical problem, a kind of high accuracy air refraction that the present invention proposes measures indirectly, wireless Send system, including power module, Temperature Humidity Sensor, barometric pressure sensor, main control chip, power amplifier module, impedance Distribution road, antenna radiating circuit and coordinator；Described main control chip controls described Temperature Humidity Sensor collecting temperature and humidity letter Cease and control described barometric pressure sensor and gather atmospheric pressure information, the described main control chip described temperature and humidity sensing to receiving The serial data signal that device and barometric pressure sensor send processes, thus calculates the value of air refraction, should The value of air refraction is modulated on the carrier wave of 2.4GHz and is sent to described power amplifier module；Described power amplifier module is used In receiving the signal of described main control chip and carrying out power amplification, launch signal by described antenna radiating circuit；Described impedance Match circuit is for the impedance matching between described main control chip and described power amplifier module, thus improves the transmission matter of signal Amount；Described antenna radiating circuit is for receiving the modulated signal after described power amplifier module amplifies, and sends to described coordination Device；The signal that the antenna radiating circuit received sends is demodulated the air refraction that is modulated on carrier wave by described coordinator Value.

In the present invention, described Temperature Humidity Sensor uses SHT75 temperature and humidity sensing chip, described SHT75 temperature and humidity sensing Chip is welded on to be had the paster of 8 pins and turns on the keyset of straight cutting, wherein 4 of described SHT75 temperature and humidity sensing chip Pin is unsettled foot, and remaining 4 pin includes: the first sequential input pin 1SCK, energization pins 2VCC, grounding pin 3GND and First data output pins 4DATA；Described barometric pressure sensor uses MS5803-01BA air pressure sensing chip, described MS5803-01BA air pressure sensing chip is welded on to be had the paster of 8 pins and turns on the keyset of straight cutting, described MS5803- Wherein 2 pins of 01BA air pressure sensing chip are unsettled foot, and remaining 6 pin includes: the second sequential input pin SCLK, connect Ground pin GND, complement code pin CSB, energization pins VCC, the second data output pins DATA2 and communication protocol chip select pin PS.

Described main control chip uses CC2530 chip, the first sequential input pin of described SHT75 temperature and humidity sensing chip 1SCK is connected with described main control chip the 18th pin, and the second sequential input of described MS5803-01BA air pressure sensing chip is drawn Foot SCLK is connected with described main control chip the 15th pin, the first data output pins of described SHT75 temperature and humidity sensing chip Second data output pins DATA2 of 4DATA and described MS5803-01BA air pressure sensing chip all with described main control chip the tenth Three pins connect.

Described impedance matching circuit includes: the first inductance L1, the second inductance L2, the first electric capacity C1, the second electric capacity C2, the 3rd Electric capacity C3, the 4th electric capacity C4；Described one end of first inductance L1 is connected with the 26th pin of described main control chip, the first electricity The other end of sense L1 and one end of the first electric capacity C1 connect, the other end ground connection of the first electric capacity C1, the first inductance L1 and first electricity The one end holding C1 public connecting end and the second electric capacity C2 connects, the other end power of the second electric capacity C2 and the second of amplification chip U4 Pin connects, and described one end of second inductance L2 is connected with the 25th pin of described main control chip, and the second inductance L2's is another One end is connected with one end of the 4th electric capacity C4, the other end ground connection of the 4th electric capacity C4, and the second inductance L2 and the 4th electric capacity C4 is public The one end connecting end and the 3rd electric capacity C3 connects, and the other end of the 3rd electric capacity C3 connects with the 4th pin of power with amplification chip U4 Connect.

Described antenna radiating circuit include the 5th electric capacity C5, the 6th electric capacity C6, the 7th electric capacity C7, the 3rd inductance L3, the 4th Inductance L4, first antenna J1；One end of described 5th electric capacity C5 is connected with the 11st pin of described power amplifier chip U4, the One end of the other end of five electric capacity C5 and the 6th electric capacity C6 connects, the other end ground connection of the 6th electric capacity C6, the 5th electric capacity C5 and the The public connecting end of six electric capacity C6 and one end of the 3rd inductance L3 connect, the other end of the 3rd inductance L3 and the one of the 7th electric capacity C7 End connects, the other end ground connection of the 7th electric capacity C7, the 3rd inductance L3 and the public connecting end of the 7th electric capacity C7 and the 4th inductance L4 One end connect, the other end ground connection of the 4th inductance L4, first antenna J1 is connected to the 4th inductance L4 and the public affairs of the 7th electric capacity C7 Connect end altogether.

Utilize above-mentioned high accuracy air refraction indirectly to measure, wireless transmission system realize high accuracy air refraction indirect Measurement, the method for wireless transmission, comprise the following steps:

Step one: described main control chip is according to the temperature value t read from described Temperature Humidity Sensor, and unit is DEG C, utilizes Dagger-axe husband's Gray's odd-prescription journey is calculated this saturated vapor pressure value f corresponding to temperature value condition₀:

$lg{f}_0=a_1*(1-T_1/T)+a_2*lg(T/T_1)+a_3*\[1-{10}^{b*(T/T_1-1)}\]+a_4*\[{10}^{c*(1-T_1/T)}-1\]+a_5---\left(1\right)$

In formula (1), T₁For triple point of water, T₁=273.16K；T=t+273.15, unit is Kelvin；a₁= 10.79574, a₂=-5.028, a₃=1.50475 × 10^-4, b=-8.2969, a₄=0.42873 × 10^-3, c=4.76955, a₅ =0.78614；

Step 2: humidity value and the step one calculated saturated vapor pressure value that will read from described Temperature Humidity Sensor This steam partial pressure f corresponding to humidity value condition is drawn after being multiplied, it may be assumed that

F=f₀* RH% (2)

In formula (2), RH% is relative humidity, and its maximum is 1；

Step 3: described target wavelength λ, as target wavelength λ, is substituted into standard dry air by the wavelength of a selected light Dispersion equation in normal conditions, calculates the air refraction n under standard state_s:

$(n_s-1)*{10}^8=b_1+\frac{b_2}{130-{\mathrm{\σ}}^2}+\frac{b_3}{38.9-{\mathrm{\σ}}^2}---\left(3\right)$

In formula (3), σ=1/ λ, λ unit be um, σ unit be um^-1, b₁=8342.54, b₂=2406147, b₃=15998；

Step 4: utilize the air refraction n under the described standard state that step 3 obtains_s, from described temperature and humidity sensing Temperature value t that device reads and atmospheric pressure value P that reads from described barometric pressure sensor, unit is Pa, calculates bid Quasi-dry air refractive index value n under this temperature value and this pressure condition_tp:

$(n_{tp}-1)=(n_s-1)*\frac{P}{96095.43}*\frac{\[1+{10}^{-8}*(0.601-0.00972*t)*P\]}{1+0.003661*t}---\left(4\right)$

Step 5: utilize the steam partial pressure f that step 2 obtains, the standard that the σ of step 3 acquisition and step 4 obtain Dry air refractive index value n under specified requirements_tpCalculate the air refraction n under this specified requirements_tpf:

n_tpf=n_tp-f*(3.7345-0.0401*σ²)×10^-10 (5)

Step 6: described main control chip is by this air refraction n_tpfValue be modulated on the carrier wave of 2.4GHz, signal pass through After impedance matching and amplification, launch the signal through ovennodulation by described antenna radiating circuit, finally will letter through described coordinator Number it is demodulated into air refraction n_tpfValue.

Owing to have employed technique scheme, the invention has the beneficial effects as follows:

System structure is simple, and volume is little, it is simple to carry, it is not necessary to wiring, and networking is convenient, low in energy consumption, can be to air refraction Rate carries out measurement during high-precision real, it is possible to by being wirelessly sent to long-range coordinator and then handing at terminal Reason.

Accompanying drawing explanation

Fig. 1 be the present invention high accuracy air refraction indirectly measure, the circuit diagram of wireless transmission system；

Fig. 2 be the present invention high accuracy air refraction indirectly measure, the theory diagram of wireless transmission system.

Detailed description of the invention

All features disclosed in this specification, or disclosed all methods or during step, except mutually exclusive Feature or step beyond, all can combine by any way, unless specifically stated otherwise, each feature is a series of equivalence or class Like an example in feature.

A kind of high accuracy air refraction that the present invention proposes is measured indirectly, wireless transmission system, as in figure 2 it is shown, this is System includes power module, Temperature Humidity Sensor U1, barometric pressure sensor U2, main control chip U3, power amplifier module U4, impedance Match circuit, antenna radiating circuit and coordinator.

As it is shown in figure 1, described Temperature Humidity Sensor U1 uses SHT75 temperature and humidity sensing chip, described SHT75 humiture passes Sense chip is welded on to be had the paster of 8 pins and turns on the keyset of straight cutting, wherein the 4 of described SHT75 temperature and humidity sensing chip Individual pin is unsettled foot, and remaining 4 pin includes: the first sequential input pin 1SCK, energization pins 2VCC, grounding pin 3GND With the first data output pins 4DATA；Described barometric pressure sensor U2 uses MS5803-01BA air pressure sensing chip, described MS5803-01BA air pressure sensing chip is welded on to be had the paster of 8 pins and turns on the keyset of straight cutting, described MS5803- Wherein 2 pins of 01BA air pressure sensing chip are unsettled foot, and remaining 6 pin includes: the second sequential input pin SCLK, connect Ground pin GND, complement code pin CSB, energization pins VCC, the second data output pins DATA2 and communication protocol chip select pin PS.

Described main control chip U3 uses CC2530 chip, and the first sequential input of described SHT75 temperature and humidity sensing chip is drawn Foot 1SCK is connected with described main control chip the 18th pin, the second sequential input of described MS5803-01BA air pressure sensing chip Pin SCLK is connected with described main control chip the 15th pin, and the first data output of described SHT75 temperature and humidity sensing chip is drawn Second data output pins DATA2 of foot 4DATA and described MS5803-01BA air pressure sensing chip all with described main control chip 13 pins connect.

Described impedance matching circuit includes: the first inductance L1, the second inductance L2, the first electric capacity C1, the second electric capacity C2, the 3rd Electric capacity C3, the 4th electric capacity C4；Described one end of first inductance L1 is connected with the 26th pin of described main control chip, the first electricity The other end of sense L1 and one end of the first electric capacity C1 connect, the other end ground connection of the first electric capacity C1, the first inductance L1 and first electricity The one end holding C1 public connecting end and the second electric capacity C2 connects, the other end power of the second electric capacity C2 and the second of amplification chip U4 Pin connects, and described one end of second inductance L2 is connected with the 25th pin of described main control chip, and the second inductance L2's is another One end is connected with one end of the 4th electric capacity C4, the other end ground connection of the 4th electric capacity C4, and the second inductance L2 and the 4th electric capacity C4 is public The one end connecting end and the 3rd electric capacity C3 connects, and the other end of the 3rd electric capacity C3 connects with the 4th pin of power with amplification chip U4 Connect.

Described antenna radiating circuit include the 5th electric capacity C5, the 6th electric capacity C6, the 7th electric capacity C7, the 3rd inductance L3, the 4th Inductance L4, first antenna J1；One end of described 5th electric capacity C5 is connected with the 11st pin of described power amplifier chip U4, the One end of the other end of five electric capacity C5 and the 6th electric capacity C6 connects, the other end ground connection of the 6th electric capacity C6, the 5th electric capacity C5 and the The public connecting end of six electric capacity C6 and one end of the 3rd inductance L3 connect, the other end of the 3rd inductance L3 and the one of the 7th electric capacity C7 End connects, the other end ground connection of the 7th electric capacity C7, the 3rd inductance L3 and the public connecting end of the 7th electric capacity C7 and the 4th inductance L4 One end connect, the other end ground connection of the 4th inductance L4, first antenna J1 is connected to the 4th inductance L4 and the public affairs of the 7th electric capacity C7 Connect end altogether.

In the present invention, described main control chip U3 controls described Temperature Humidity Sensor U1 collecting temperature and humidity information and control Described barometric pressure sensor U2 gathers atmospheric pressure information, the described main control chip U3 described Temperature Humidity Sensor U1 to receiving The serial data signal sent with barometric pressure sensor U2 processes, thus calculates the value of air refraction, should The value of air refraction is modulated on the carrier wave of 2.4GHz and is sent to described power amplifier module U4；Described power amplifier module U4, for receiving the signal of described main control chip U3 and carrying out power amplification, launches signal by described antenna radiating circuit；Institute State impedance matching circuit for the impedance matching between described main control chip U3 and described power amplifier module U4, thus improve letter Number transmission quality；Described antenna radiating circuit is for receiving the modulated signal after described power amplifier module U4 amplifies, concurrently Deliver to described coordinator；The signal that the antenna radiating circuit received sends is demodulated and is modulated on carrier wave by described coordinator The value of air refraction.

Utilize the present invention high accuracy air refraction indirectly measure, the implementation method of wireless transmission system, including following step Rapid:

Step one: described main control chip U3 is according to the temperature value t read from described Temperature Humidity Sensor U1, and unit is DEG C, Dagger-axe husband's Gray's odd-prescription journey is utilized to be calculated this saturated vapor pressure value f corresponding to temperature value condition₀:

$lg{f}_0=a_1*(1-T_1/T)+a_2*lg(T/T_1)+a_3*\[1-{10}^{b*(T/T_1-1)}\]+a_4*\[{10}^{c*(1-T_1/T)}-1\]+a_5---\left(1\right)$

In formula (1), T₁For triple point of water, T₁=273.16K；T=t+273.15, unit is Kelvin；a₁= 10.79574, a₂=-5.028, a₃=1.50475 × 10^-4, b=-8.2969, a₄=0.42873 × 10^-3, c=4.76955, a₅ =0.78614；

Step 2: humidity value and the calculated saturated vapor pressure of step one that will read from described Temperature Humidity Sensor U1 Value draws this steam partial pressure f corresponding to humidity value condition after being multiplied, it may be assumed that

F=f₀* RH% (2)

In formula (2), RH% is relative humidity, and its maximum is 1；

Step 3: select the wavelength of a light as required as target wavelength λ, such as in LDMS, quilt The wavelength of the light that range finding distance values uses to system is directly proportional, then the wavelength of the light that should system be used is as target wavelength λ；Example again In testing at visible ray, the wavelength of the light that should this experiment be used is as target wavelength λ；In optical imagery detection it is the most such as In system, therefore, the wavelength of the light that should system be used is as target wavelength λ；Described target wavelength λ is substituted into standard dry air Dispersion equation in normal conditions, calculates the air refraction n under standard state_s:

$(n_s-1)*{10}^8=b_1+\frac{b_2}{130-{\mathrm{\σ}}^2}+\frac{b_3}{38.9-{\mathrm{\σ}}^2}---\left(3\right)$

In formula (3), σ=1/ λ, λ unit be um, σ unit be um^-1, b₁=8342.54, b₂=2406147, b₃=15998；

Step 4: utilize the air refraction n under the described standard state that step 3 obtains_s, from described temperature and humidity sensing Temperature value t that device U1 reads and atmospheric pressure value P that reads from described barometric pressure sensor, unit is Pa, calculates Standard dry air refractive index value n under this temperature value and this pressure condition_tp:

$(n_{tp}-1)=(n_s-1)*\frac{P}{96095.43}*\frac{\[1+{10}^{-8}*(0.601-0.00972*t)*P\]}{1+0.003661*t}---\left(4\right)$

Step 5: utilize the steam partial pressure f that step 2 obtains, the standard that the σ of step 3 acquisition and step 4 obtain Dry air refractive index value n under specified requirements_tpCalculate the air refraction n under this specified requirements_tpf:

n_tpf=n_tp-f*(3.7345-0.0401*σ²)×10^-10 (5)

Step 6: described main control chip U3 is by this air refraction n_tpfValue be modulated on the carrier wave of 2.4GHz, signal warp After crossing impedance matching and amplifying, launch the signal through ovennodulation by described antenna radiating circuit, finally will through described coordinator Signal is demodulated into air refraction n_tpfValue.

The invention is not limited in aforesaid detailed description of the invention.The present invention expands to any disclose in this manual New feature or any new combination, and the arbitrary new method that discloses or the step of process or any new combination.

Claims (6)

1. a high accuracy air refraction indirectly measure, wireless transmission system, it is characterised in that include power module, warm and humid Degree sensor (U1), barometric pressure sensor (U2), main control chip (U3), power amplifier module (U4), impedance matching circuit, sky Line radiating circuit and coordinator；

Described main control chip (U3) controls described Temperature Humidity Sensor (U1) collecting temperature and humidity information and controls described air Pressure transducer (U2) gathers atmospheric pressure information, the described main control chip (U3) the described Temperature Humidity Sensor (U1) to receiving and The serial data signal that barometric pressure sensor (U2) sends processes, thus calculates the value of air refraction, should The value of air refraction is modulated on the carrier wave of 2.4GHz and is sent to described power amplifier module (U4)；Described power amplification mould Block (U4) is used for receiving the signal of described main control chip (U3) and carrying out power amplification, launches letter by described antenna radiating circuit Number；Described impedance matching circuit is used for the impedance matching between described main control chip (U3) and described power amplifier module (U4), Thus improve the transmission quality of signal；Described antenna radiating circuit is used for receiving after described power amplifier module (U4) amplifies Adjust signal, and send to described coordinator；The signal that the antenna radiating circuit received sends is demodulated tune by described coordinator The value of system air refraction on carrier wave.

The most according to claim 1 high accuracy air refraction indirectly measure, wireless transmission system, it is characterised in that described Temperature Humidity Sensor (U1) uses SHT75 temperature and humidity sensing chip, and described SHT75 temperature and humidity sensing chip is welded on has 8 The paster of pin turns on the keyset of straight cutting, and wherein 4 pins of described SHT75 temperature and humidity sensing chip are unsettled foot, and remaining is 4 years old Individual pin includes: the first sequential input pin 1SCK, energization pins 2VCC, grounding pin 3GND and the first data output pins 4DATA；Described barometric pressure sensor (U2) uses MS5803-01BA air pressure sensing chip, described MS5803-01BA air pressure transmission Sense chip is welded on to be had the paster of 8 pins and turns on the keyset of straight cutting, its of described MS5803-01BA air pressure sensing chip In 2 pins be unsettled foot, remaining 6 pin includes: the second sequential input pin SCLK, grounding pin GND, complement code pin CSB, energization pins VCC, the second data output pins DATA2 and communication protocol chip select pin PS.

The most according to claim 2 high accuracy air refraction indirectly measure, wireless transmission system, it is characterised in that described Main control chip (U3) uses CC2530 chip, the first sequential input pin 1SCK and institute of described SHT75 temperature and humidity sensing chip State main control chip the 18th pin connect, the second sequential input pin SCLK of described MS5803-01BA air pressure sensing chip with Described main control chip the 15th pin connects, the first data output pins 4DATA of described SHT75 temperature and humidity sensing chip and institute State the second data output pins DATA2 of MS5803-01BA air pressure sensing chip all with described main control chip the 13rd pin even Connect.

The most according to claim 1 high accuracy air refraction indirectly measure, wireless transmission system, it is characterised in that described Impedance matching circuit includes: the first inductance L1, the second inductance L2, the first electric capacity C1, the second electric capacity C2, the 3rd electric capacity C3, the 4th Electric capacity C4；Described one end of first inductance L1 is connected with the 26th pin of described main control chip, another of the first inductance L1 End is connected with one end of the first electric capacity C1, the other end ground connection of the first electric capacity C1, the first inductance L1 and the first public company of electric capacity C1 Connecing end to be connected with one end of the second electric capacity C2, the other end power of the second electric capacity C2 is connected with second pin of amplification chip U4, Described one end of second inductance L2 is connected with the 25th pin of described main control chip, the other end and the 4th of the second inductance L2 One end of electric capacity C4 connects, the other end ground connection of the 4th electric capacity C4, the second inductance L2 and the 4th electric capacity C4 public connecting end and the One end of three electric capacity C3 connects, and the other end of the 3rd electric capacity C3 is connected with the 4th pin of amplification chip U4 with power.

The most according to claim 1 high accuracy air refraction indirectly measure, wireless transmission system, it is characterised in that described Antenna radiating circuit include the 5th electric capacity C5, the 6th electric capacity C6, the 7th electric capacity C7, the 3rd inductance L3, the 4th inductance L4, first day Line J1；One end of described 5th electric capacity C5 is connected with the 11st pin of described power amplifier chip U4, and the 5th electric capacity C5's is another One end is connected with one end of the 6th electric capacity C6, the other end ground connection of the 6th electric capacity C6, the 5th electric capacity C5 and the public affairs of the 6th electric capacity C6 The one end connecting end and the 3rd inductance L3 altogether connects, and the other end of the 3rd inductance L3 and one end of the 7th electric capacity C7 connect, and the 7th The other end ground connection of electric capacity C7, one end of the 3rd inductance L3 and the public connecting end of the 7th electric capacity C7 and the 4th inductance L4 connects, The other end ground connection of the 4th inductance L4, first antenna J1 is connected to the 4th inductance L4 and the public connecting end of the 7th electric capacity C7.

6. one kind high accuracy air refraction indirectly measure, radio communication method, it is characterised in that utilize such as claim 1 to 5 Arbitrary described high accuracy air refraction is measured indirectly, wireless transmission system, and comprises the following steps:

Step one: described main control chip (U3) is according to the temperature value t that reads from described Temperature Humidity Sensor (U1), and unit is DEG C, Dagger-axe husband's Gray's odd-prescription journey is utilized to be calculated this saturated vapor pressure value f corresponding to temperature value condition₀:

$\lg f_0=a_1*(1-T_1/T)+a_2*\lg (T/T_1)+a_3*\[1-{10}^{b*(T/T_1-1)}\]+a_4*\[{10}^{c*(1-T_1/T)}-1\]+a_5---\left(1\right)$

In formula (1), T₁For triple point of water, T₁=273.16K；T=t+273.15, unit is Kelvin；a₁= 10.79574, a₂=-5.028, a₃=1.50475 × 10^-4, b=-8.2969, a₄=0.42873 × 10^-3, c=4.76955, a₅ =0.78614；

Step 2: the humidity value that will read from described Temperature Humidity Sensor (U1) and step one calculated saturated vapor pressure value This steam partial pressure f corresponding to humidity value condition is drawn after being multiplied, it may be assumed that

F=f₀* RH% (2)

In formula (2), RH% is relative humidity, and its maximum is 1；

Step 3: described target wavelength λ, as target wavelength λ, is substituted into standard dry air at mark by the wavelength of a selected light Dispersion equation under quasi-state, calculates the air refraction n under standard state_s:

$(n_s-1)*{10}^8=b_1+\frac{b_2}{130-{\mathrm{\σ}}^2}+\frac{b_3}{38.9-{\mathrm{\σ}}^2}---\left(3\right)$

In formula (3), σ=1/ λ, λ unit be um, σ unit be um^-1, b₁=8342.54, b₂=2406147, b₃=15998；

Step 4: utilize the air refraction n under the described standard state that step 3 obtains_s, from described Temperature Humidity Sensor (U1) The temperature value t read and atmospheric pressure value P read from described barometric pressure sensor, unit is Pa, calculates standard Dry air refractive index value n under this temperature value and this pressure condition_tp:

$(n_{tp}-1)=(n_s-1)*\frac{P}{96095.43}*\frac{\[1+{10}^{-8}*(0.601-0.00972*t)*P\]}{1+0.003661*t}---\left(4\right)$

Step 5: utilize the steam partial pressure f that step 2 obtains, σ and the standard of step 4 acquisition that step 3 obtains are dried Air refractive index value n under specified requirements_tpCalculate the air refraction n under this specified requirements_tpf:

n_tpf=n_tp-f*(3.7345-0.0401*σ²)×10^-10 (5)

Step 6: described main control chip (U3) is by this air refraction n_tpfValue be modulated on the carrier wave of 2.4GHz, signal pass through After impedance matching and amplification, launch the signal through ovennodulation by described antenna radiating circuit, finally will letter through described coordinator Number it is demodulated into air refraction n_tpfValue.