CN204575535U - Airport Back visiometer measuring system - Google Patents

Abstract

The utility model relates to a kind of airport Back visiometer measuring system, it comprises Back visibility measurement module, background luminance measurement module, runway lights optical module and control module are formed, Back visibility measurement module and background luminance measurement module are positioned over one end of airfield runway, Back visibility measurement module is connected to control module by RS485 or LAN interface, Back visibility measurement module exports atmospheric extinction coefficient, background luminance measurement module is connected to control module by RS485 or LAN interface, background luminance measurement module is for exporting runway background light level, runway lights optical module output intensity grade is to control module.Homeplate Back visiometer measuring system, the calculating of runway visual range is based upon on Cauchy's Mead law and A Luode law basis, adopt Back transmittance meter, the error of different acceptance point is relatively fixing, carries out RVR measure more accurate on airport.

Description

Airport Back visiometer measuring system

Technical field

The utility model relates to visibility at the airport measuring system, particularly a kind of airport Back visiometer measuring system.

Background technology

Visibility (Visibility) is the amount by human observers's quantitative predication first defined in order to meteorological object, and the observation carried out by this way was once widely adopted.Visibility observation is mainly limited by the atmospheric extinction coefficient that suspension solid in an atmosphere and liquid particle cause; Primarily of the scattering of light, non-absorbing caused in delustring.Its estimated value is comply with in the vision of individual and is changed visible understanding level, simultaneously by the impact of light source characteristic sum transmission factor.Therefore, the eye estimate of visibility is all subjective.But basic meteorology amount, i.e. atmospheric transparency, can objectively measure, and represents with meteorological optical range (MOR), can measure extinction coefficient with instrumental method thus calculate.Use fixing instrument be extinction coefficient with apart from separate hypothesis basis.At present, some instruments directly measure decay, the scattering of other apparatus measures light, all in order to draw extinction coefficient.Wherein, transmittance meter mainly comprises atmospheric transmission instrument, forward scattering type visiometer.Wherein, atmospheric transmission instrument is because baseline is constant in the process used, and baseline is shorter, is unsuitable for the measurement environment that this baseline of airfield runway is longer, so cause visibility at the airport measurement accuracy not high.Employing two point sampling of forward scattering instrument, its sample space is little, causes its accuracy being applied to airfield runway visibility measurement also not good enough.Be badly in need of one and be applicable to airfield runway visual range, ensure the Visibility Measures System of measurement accuracy.

Summary of the invention

The purpose of this utility model is to overcome the deficiencies in the prior art, a kind of airport Back visiometer measuring system is provided, it is suitable for the visibility measurement compared with Long baselines, and sample space is large simultaneously, thus improves the accuracy of visibility measurement to a great extent.

The utility model solves its technical matters and is achieved through the following technical solutions:

A kind of airport Back visiometer measuring system, it is characterized in that: comprise Back visibility measurement module, background luminance measurement module, runway lights optical module and control module are formed, Back visibility measurement module and background luminance measurement module are positioned over one end of airfield runway, Back visibility measurement module is connected to control module by RS485 or LAN interface, Back visibility measurement module exports atmospheric extinction coefficient, background luminance measurement module is connected to control module by RS485 or LAN interface, background luminance measurement module is for exporting runway background light level, runway lights optical module exports runway light intensity to control module.

And described background luminance measurement module adopts Visa to draw LM21 background luminance sensor.

And described runway lights optical module adopts lamp stand or light station.

And described Back visibility measurement module adopts Back visiometer.

Advantage of the present utility model and beneficial effect are:

1, homeplate Back visiometer measuring system, the calculating of runway visual range (RVR) is based upon on Cauchy's Mead law and A Luode law basis, Cauchy's Mead law is used to calculate runway visual range RVR between daytime, night and runway lights use A Luode law to calculate runway visual range RVR when opening, adopt Back transmittance meter, the error of different acceptance point is relatively fixing, carries out RVR measure more accurate on airport.

2, homeplate Back visiometer measuring system, use Cauchy's Mead law to calculate runway visual range RVR between daytime, Cauchy's Mead law can be expressed as:

ε＝e ^-σv(1)

In formula, ε is visual contrast sense threshold, and ICAO recommends ε=0.05, can obtain meteorological optical range (MOR), is also RVR between daytime:

$V=-\frac{1\mathrm{n\ϵ}}{\mathrm{\σ}}=\frac{3}{\mathrm{\σ}}---\left(2\right)$

Obtain atmospheric extinction coefficient σ by Back visiometer (LIDAR), RVR between daytime can be obtained.

3, homeplate Back visiometer measuring system, night and runway lights use A Luode law to calculate runway visual range RVR when opening, be in the air of σ at atmospheric extinction coefficient, light intensity is the illumination that the light source of I produces at distance light source place is E, is A Luode law.The visibility derived accordingly can be expressed as:

$E=\frac{I}{V^2}{e}^{-\mathrm{\σV}}---\left(3\right)$

In formula, E is illumination threshold, and I is known intensity level, and σ is extinction coefficient, and V is runway visual range, and illumination threshold E is not a constant, but according to background luminance B continually varying function, available experimental formula is expressed as:

logE＝0.57log(B)+0.05[log(B)] ²-0.66 (4)

In formula (4), background luminance B measures by background luminance sensor (BLS) to obtain, unit is cd/m2, therefore, extinction coefficient σ value is obtained by Back visibility measurement module, obtain illumination threshold E according to background luminance sensor, and in conjunction with known airfield runway navigational lighting aid intensity I, RVR at night can be obtained.

Accompanying drawing explanation

Fig. 1 is system architecture schematic diagram (stereographic map) of the present utility model;

Fig. 2 is principle flow chart of the present utility model.

Description of reference numerals:

LM21 background luminance sensor, 5-Back visiometer are drawn in 1-airfield runway, 2-control tower or light station, 3-control module, 4-Visa.

Embodiment

Below by specific embodiment, the utility model is described in further detail, and following examples are just demonstrated descriptive explanation, are not determinate words, can not limit protection domain of the present utility model with this.

A kind of airport Back visiometer measuring system, it comprises Back visibility measurement module, background luminance measurement module, runway lights optical module and control module and forms.Back visibility measurement module and background luminance measurement module are positioned over one end of airfield runway, Back visibility measurement module is connected to control module by RS485 or LAN interface, Back visibility measurement module exports atmospheric extinction coefficient, background luminance measurement module is connected to control module by RS485 or LAN interface, background luminance measurement module is for exporting runway background light level, and runway lights optical module output intensity grade is to control module.

Background luminance measurement module adopts Visa to draw LM21 background luminance sensor.Runway lights optical module adopts lamp stand or light station.Back visibility measurement module adopts Back visiometer.

Airfield runway 1 earth terminal or clearing end installs a Back visiometer 5 and LM21 background luminance sensor 4 is drawn in Visa, as Fig. 1.The detection range of Back visiometer (LIDAR) is about 2km, and measurement range meets the airfield runway demand of the domestic overwhelming majority.The bias light intensity that the atmospheric extinction coefficient data that Back visiometer (LIDAR) is measured and Visa draw LM21 background luminance sensor (BLS) to measure, is sent to control module by RS485 or LAN interface.Runway lights light intensity as known quantity, is sent to the main control computer of control module 3 according to intensity level by control tower or light station 2.These data obtain runway visual range (RVR) after main control computer process.

The calculating of runway visual range (RVR) is based upon on Cauchy's Mead law and A Luode law basis.Cauchy's Mead law is used to calculate runway visual range (RVR) between daytime.

To the black objects thing being background with horizontal sky, suppose that air is homogeneous, namely atmospheric extinction coefficient σ is constant, and the brightness contrast of object and background is Cauchy's Mead law with the Changing Pattern of distance.Cauchy's Mead law can be expressed as:

ε＝e ^-σv(1)

In formula, ε is visual contrast sense threshold.ICAO recommends ε=0.05, can obtain meteorological optical range (MOR), is also RVR between daytime:

$V=-\frac{1\mathrm{n\ϵ}}{\mathrm{\σ}}=\frac{3}{\mathrm{\σ}}---\left(2\right)$

Therefore obtain atmospheric extinction coefficient σ by laser radar visibility meter and can obtain RVR between daytime.

Night and runway lights use A Luode law to calculate runway visual range (RVR) when opening.Be in the air of σ at atmospheric extinction coefficient, light intensity is the illumination that the light source of I produces at distance light source place is E, is A Luode law.The visibility derived accordingly can be expressed as:

$E=\frac{I}{V^2}{e}^{-\mathrm{\σV}}---\left(3\right)$

In formula, E is illumination threshold, and I is known intensity of light, and σ is extinction coefficient, and V is runway visual range.

Illumination threshold E is not a constant, but according to background luminance B continually varying function, available experimental formula is expressed as:

logE＝0.57log(B)+0.05[log(B)] ²-0.66 (4)

Wherein, background luminance B is obtained by background luminance sensor measurement, and unit is cd/m2.

Therefore, obtain extinction coefficient σ value by laser radar visibility meter, obtain illumination threshold E according to background luminance sensor, and in conjunction with known airfield runway navigational lighting aid intensity I, RVR at night can be obtained.

Although disclose embodiment of the present utility model and accompanying drawing for the purpose of illustration, but it will be appreciated by those skilled in the art that: in the spirit and scope not departing from the utility model and claims, various replacement, change and amendment are all possible, therefore, scope of the present utility model is not limited to the content disclosed in embodiment and accompanying drawing.

Claims (4)

1. an airport Back visiometer measuring system, it is characterized in that: comprise Back visibility measurement module, background luminance measurement module, runway lights optical module and control module are formed, Back visibility measurement module and background luminance measurement module are positioned over one end of airfield runway, Back visibility measurement module is connected to control module by RS485 or LAN interface, Back visibility measurement module exports atmospheric extinction coefficient, background luminance measurement module is connected to control module by RS485 or LAN interface, background luminance measurement module is for exporting runway background light level, runway lights optical module exports runway light intensity to control module.

2. airport according to claim 1 Back visiometer measuring system, is characterized in that: described background luminance measurement module adopts Visa to draw LM21 background luminance sensor.

3. airport according to claim 1 Back visiometer measuring system, is characterized in that: described runway lights optical module adopts lamp stand or light station.

4. airport according to claim 1 Back visiometer measuring system, is characterized in that: described Back visibility measurement module adopts Back visiometer.