CN101598780B - Local airport monitoring method, device and system therefor - Google Patents

Abstract

The invention provides a local airport monitoring method, a device and a system therefor. The method comprises: receiving satellite data transmitted by each receiver and calculating pseudorange corrected value corresponding to each receiver; selecting any receiver at will as a pseudo onboard user and calculating pseudorange corrected value positioning error of the pseudo onboard user; calculating monitor system positioning error of the pseudo onboard user and calculating to obtain ground monitor protection level of the pseudo onboard user according to the monitor system positioning error and wide area augmentation system (WAAS) information promulgation error; comparing ground monitor protection level of all the satellite combination of the pseudo onboard user and preset alarm limit value of the pseudo onboard user, and outputting the optimal satellite combination according to the comparison result. The invention performs calculation of pseudorange corrected value error and monitor system error on the onboard user by a ground monitor end, finishes selection of the onboard user optimal visible satellite combination by detection of ground monitor protection level, reduces calculation load of onboard user and improves instantaneity.

Description

Local airport monitoring method, Apparatus and system

Technical field

Embodiment of the invention satellite navigation technical field relates in particular to a kind of local airport monitoring method, Apparatus and system.

Background technology

When satellite navigation system is applied in the civil aviation aspect, must satisfy precision, integrity, continuity and four performance index of availability usually.Wherein, precision is meant the measuring position of navigational system and the difference of actual position at any time; Integrity is meant when system can't provide navigation Service, the ability that it can in time give a warning or close; Continuity is meant that system provides service ability in whole flight course; Availability is meant when the user needs, the ability that system may be used to navigate.But because present satellite navigation system can be subjected to the influence of factors such as availability number of satellite, atmosphere, ionosphere, thundercloud usually, and the dynamic behaviour influence that is subjected to aircraft, no matter be GPS (the Globle Positioninng System of the U.S.; Hereinafter to be referred as GPS), or Muscovite GPS (Global Position System) (Global Navigation Satellite System; Hereinafter to be referred as GLONASS), all can't satisfy the navigation performance requirement of above several aspects comprehensively.Therefore, for integrality, precision, availability and the continuous service that improves satellite navigation system, satellite navigation reinforcing system has just formed, it is by some ground and satellite facility, on the basis of selecting technology such as use differential technique and pseudo satellite, pseudolite technology, can improve the performance of satellite navigation system.

Present satellite navigation reinforcing system can be divided into three kinds: ground enhanced system, satellite-based augmentation system and space base enhanced system, and wherein, the representative of ground enhanced system is the Local Area Augmentation System of the U.S. (Local Area Augmentation System; Hereinafter to be referred as LAAS).The differential technique that LAAS uses is based on the modified value that produces the concomitant error of all expectations between a local reference station and the subscriber station, so, LAAS can only be in about 20 nautical miles " this locality " scope broadcast navigation update information, its service clearance only is included in the airport in the one's respective area.In addition, owing to be subjected to the influence of ionospheric storm, the integrity of LAAS can not get guaranteeing, makes the authentication of LAAS become very difficult.

The representative of satellite-based augmentation system is Wide Area Augmentation System (the Wide Area Augmentation System of the U.S.; Hereinafter to be referred as WAAS) and European worldwide navigation eclipse system (the European Geostationary Navigation Overlay Service of European Union; Hereinafter to be referred as EGNOS) system.These two systems all are by geosynchronous satellite (Geostationary Orbit; Hereinafter to be referred as GEO) broadcast control information to the user, but, make its integrity can not reach the performance requirement of civil aviaton's precision approach owing to do not carry out local monitoring.

The representative of space base enhanced system is receiver-autonomous formula integrity monitoring (the Receiver Autonomous Integrity Monitoring of system; Hereinafter to be referred as RAIM).Though RAIM is present a kind of simple and effective completeness monitoring method, still there is the problem of availability in the RAIM method.So-called RAIM availability is exactly in some event, and the monitoring result that can't carry out RAIM monitoring or RAIM can not guarantee to satisfy simultaneously false alarm rate and loss requirement.Cause the factor of RAIM availability issue to mainly contain two kinds: the one, the observation satellite number deficiency, RAIM needs while at least 5 satellites just can carry out the redundant information consistency check and come detection failure, and at least 6 satellites just can carry out the Fault Identification operation.Just the situation that the number of satellite deficiency causes the RAIM monitoring not carry out can occur in some events, it is the RAIM cavity that this situation of title is also arranged.The 2nd, the geometric distributions factor.Though some event number of satellite satisfied the basic demand of RAIM, the geometric layout of satellite may cause when carrying out integrity monitoring, can't detect the fault that appears on some satellite, the result can't guarantee the requirement of loss.Therefore, on the whole, the RAIM method still is not suitable for being used for carrying out integrity monitoring.

For the LAAS system that makes satellite navigation reaches the performance of I class precision approach, (the Federal Aviation Administration of US Federal Aviation Administration; Hereinafter to be referred as FAA) with itself and WAAS system combined after, a kind of local airport monitoring system (Local Airport Monitor has been proposed again; Hereinafter to be referred as LAM), it eliminates the influence of ionospheric storm to system in the bearing accuracy and each performance that improve satellite navigation.But most of integrity algorithm of LAM of the prior art system all needs airborne user self to finish, and has increased the weight of burden for users, has reduced real-time.

Summary of the invention

The embodiment of the invention provides a kind of local airport monitoring method, Apparatus and system, all need airborne user self to finish in order to the most of integrity algorithm that solves LAM of the prior art system, increase the weight of burden for users, reduced the defective of practicality, improved the performance of local airport monitoring method and system.

The embodiment of the invention provides a kind of local airport monitoring method, comprising:

Obtain the receiver information and the receiver of each receiver itself and levy the satellite data that star receives from navigation, the enhancing information, carrier phase observation data and the tropospheric error model that utilize Wide Area Augmentation System to broadcast are proofreaied and correct the pseudorange information in the described satellite data, obtain the pseudo-range corrections value of every satellite of each receiver correspondence, described receiver information comprises the actual distance between satellite elevation angle value, receiver and its visible satellite of the visible satellite of receiver correspondence and the visible satellite number of each receiver;

Optional receiver is pseudo-airborne user, according to the airborne user's of described puppet the described receiver information and the continuity requirements of airborne user preset, utilize the pseudorange territory to obtain the airborne user's of described puppet pseudo-range corrections value positioning error, and from described pseudo-range corrections value positioning error, extract the airborne user's of described puppet Wide Area Augmentation System information distributing positioning error to the transform matrix calculations of locator field;

According to the airborne user's of described puppet the described receiver information and the integrity value-at-risk of systemic presupposition, utilize described pseudorange territory to obtain the airborne user's of described puppet surveillance positioning error to the transform matrix calculations of locator field, and described surveillance positioning error and described Wide Area Augmentation System information distributing positioning error sum carried out the calculating of desirable envelope value, obtain the airborne user's of described puppet ground monitoring protected level, described surveillance positioning error comprises the positioning error that is caused by airborne user's thermonoise and fuselage multipath, the positioning error that the positioning error that is caused by the ionosphere in the monitoring center sky and the troposphere in the monitoring center sky cause;

The ground monitoring protected level of all visible satellites combination of the airborne user of described puppet is compared with the alarm limit value of airborne user preset successively; if, then will comprising the pseudo-range corrections value of every visible satellite in maximum visible satellite combination of number of satellite and the combination of this visible satellite less than described alarm limit value, the ground monitoring protected level of described visible satellite combination sends to described airborne user.

The embodiment of the invention provides a kind of local airport monitoring device, comprising:

First computing module, be used to obtain receiver information of each receiver itself and the satellite data that receiver receives from Navsat, the enhancing information, carrier phase observation data and the tropospheric error model that utilize Wide Area Augmentation System to broadcast are proofreaied and correct the pseudorange information in the described satellite data, obtain the pseudo-range corrections value of every satellite of each receiver correspondence, described receiver information comprises the actual distance between satellite elevation angle value, receiver and its visible satellite of the visible satellite of receiver correspondence and the visible satellite number of each receiver;

Second computing module, be connected with described first computing module, being used for optional receiver is pseudo-airborne user, according to the airborne user's of described puppet the described receiver information and the continuity requirements of airborne user preset, utilize the pseudorange territory to obtain the airborne user's of described puppet pseudo-range corrections value positioning error, and from described pseudo-range corrections value positioning error, extract the airborne user's of described puppet Wide Area Augmentation System information distributing positioning error to the transform matrix calculations of locator field;

The 3rd computing module, be connected with described second computing module, be used for according to the airborne user's of described puppet the described receiver information and the integrity value-at-risk of systemic presupposition, utilize described pseudorange territory to obtain the airborne user's of described puppet surveillance positioning error to the transform matrix calculations of locator field, and described surveillance positioning error and described Wide Area Augmentation System information distributing positioning error sum carried out the calculating of desirable envelope value, obtain the airborne user's of described puppet ground monitoring protected level, described surveillance positioning error comprises the positioning error that is caused by airborne user's thermonoise and fuselage multipath, the positioning error that the positioning error that is caused by the ionosphere in the monitoring center sky and the troposphere in the monitoring center sky cause;

Judging module; be connected with described the 3rd computing module; be used for the ground monitoring protected level of all visible satellites combination of the airborne user of described puppet is compared with the alarm limit value of airborne user preset successively; if, then will comprising the pseudo-range corrections value of every visible satellite in maximum visible satellite combination of number of satellite and the combination of this visible satellite less than described alarm limit value, the ground monitoring protected level of described visible satellite combination sends to described airborne user.

The embodiment of the invention provides a kind of local airport monitoring system, comprising:

A plurality of receivers, be used to receive the satellite data that Navsat sends, described satellite data is carried out analog to digital conversion, and will through conversion behind the modulus satellite data and the receiver information of himself send to monitoring center, described receiver information comprises the true distance between satellite elevation angle value, receiver and its visible satellite of the visible satellite of receiver correspondence and the visible satellite number of each receiver;

One monitoring center; be connected with described receiver; be used for calculating the pseudo-range corrections value of every satellite of described receiver correspondence according to the satellite data that receives; and the error that the sum of errors surveillance that airborne user's pseudo-range corrections value is caused according to described receiver information causes detects; calculate the ground monitoring protected level of described monitoring center; and by big or small comparative result to the alarm limit value of described ground monitoring protected level and user preset; obtain available combinations of satellites; the pseudo-range corrections value of every visible satellite in described available combinations of satellites and this combinations of satellites is sent to airborne user

Described monitoring center comprises: first computing module, be used to obtain receiver information of each receiver itself and the satellite data that receiver receives from Navsat, the enhancing information of utilizing Wide Area Augmentation System to broadcast, carrier phase observation data and tropospheric error model are proofreaied and correct the pseudorange information in the described satellite data, obtain the pseudo-range corrections value of every satellite of each receiver correspondence, described receiver information comprises the satellite elevation angle value of the visible satellite of receiver correspondence, the actual distance between receiver and its visible satellite and the visible satellite number of each receiver;

Second computing module, be connected with described first computing module, being used for optional receiver is pseudo-airborne user, according to the airborne user's of described puppet the described receiver information and the continuity requirements of airborne user preset, utilize the pseudorange territory to obtain the airborne user's of described puppet pseudo-range corrections value positioning error, and from described pseudo-range corrections value positioning error, extract the airborne user's of described puppet Wide Area Augmentation System information distributing positioning error to the transform matrix calculations of locator field;

The 3rd calculates mould determines, be connected with described second computing module, be used for according to the airborne user's of described puppet the described receiver information and the integrity value-at-risk of systemic presupposition, utilize described pseudorange territory to obtain the airborne user's of described puppet surveillance positioning error to the transform matrix calculations of locator field, and described surveillance positioning error and described Wide Area Augmentation System information distributing positioning error sum carried out the calculating of desirable envelope value, obtain the airborne user's of described puppet ground monitoring protected level, described surveillance positioning error comprises the positioning error that is caused by airborne user's thermonoise and fuselage multipath, the positioning error that the positioning error that is caused by the ionosphere in the monitoring center sky and the troposphere in the monitoring center sky cause;

Judging module, be connected with described the 3rd computing module, be used for the ground monitoring protected level of all visible satellites combination of the airborne user of described puppet is compared with the alarm limit value of airborne user preset successively, if, then will comprising the pseudo-range corrections value of every visible satellite in maximum visible satellite combination of number of satellite and the combination of this visible satellite less than described alarm limit value, the ground monitoring protected level of described visible satellite combination sends to described airborne user;

One airborne user is connected with described monitoring center, the position that the pseudo-range corrections value that visible satellite makes up and visible satellite makes up that is used for sending according to described monitoring center is calculated described airborne user.

The local airport monitoring method of the embodiment of the invention; Apparatus and system; by airborne user being carried out the detection of the error that sum of errors surveillance that the pseudo-range corrections value causes causes in the monitoring side on ground; and definition obtains the notion of ground monitoring protected level in view of the above; airborne user's self protected level calculating is transformed in the calculating of monitoring center to ground monitoring and protecting level on ground; thereby by choosing the best visible satellite combination of airborne user finished in the detection of the protected level of ground inspection center; oneself carry out the method for satellite subclass selection compares with airborne user in the existing system; when guaranteeing system accuracy; also improved the robustness of system; reduce airborne user's computation burden, improved real-time.

Description of drawings

Fig. 1 is the process flow diagram of local airport monitoring method embodiment one of the present invention;

Fig. 2 is the process flow diagram of local airport monitoring method embodiment two of the present invention;

Fig. 3 is the structural representation of local airport monitoring device embodiment of the present invention;

Fig. 4 is the structural representation of local airport monitoring system embodiment of the present invention.

Embodiment

Further specify the technical scheme of the embodiment of the invention below in conjunction with the drawings and specific embodiments.

Flourish along with the satellite navigation cause, countries in the world be all in the satellite navigation system of building oneself, as the GPS of USA system, and Muscovite GLONASS system, and the Galileo in the Europe of building (Galileo) system.Yet, since ionosphere, the troposphere, the influence of multipath effect and thermonoise, and the problem of satellite navigation system self, as ephemeris error, star clock error etc. make satellite navigation all can not satisfy the desired performance index of system in a lot of application facet.For example, in aircarrier aircraft precision approach system applies, not only the satellite navigation precision has been proposed very high requirement, simultaneously to its integrity, the requirement of continuity and availability is also very harsh.

In order to overcome the above problems, the researcher of navigation field has invented a lot of backup systems and has strengthened satellite navigation system.At present, typical satellite navigation strengthens WAAS and the LAAS that the U.S. is arranged, the EGNOS of European Union, satellite-based augmentation system (Multi-Functional Satellite Augmentation System of Japan; Hereinafter to be referred as MSAS) etc.But because in the aircarrier aircraft precision approach system applies, its integrity still can not reach the performance requirement of civil aviaton's precision approach, based on this, correlative study person has proposed the LAM system.Yet the LAM system of prior art lacks data check, and robustness is relatively poor, and simultaneously, most of integrity algorithm all needs airborne user self to finish, and has increased the weight of burden for users, has reduced real-time.

Therefore; on the basis of LAM system; the embodiment of the invention has proposed a kind of local airport monitoring method; Apparatus and system; this local airport monitoring method all realizes at the ground monitoring center; its by in the monitoring center on ground at receiver; what monitoring center and airborne user caused itself detects and estimate airborne user's satellite position error; and obtain the ground monitoring protected level in the ground monitoring center calculation; airborne user's protected level is calculated in the calculating that is transformed into ground monitoring and protecting level; thereby reduced airborne user's computation burden, improved real-time.

Fig. 1 is the process flow diagram of local airport monitoring method embodiment one of the present invention, and as shown in Figure 1, this enforcement local airport monitoring method comprises:

Step 100, obtain receiver information of each receiver itself and the satellite data that receiver receives from Navsat, the enhancing information, carrier phase observation data and the tropospheric error model that utilize Wide Area Augmentation System to broadcast are proofreaied and correct the pseudorange information in the described satellite data, obtain the pseudo-range corrections value of every satellite of each receiver correspondence;

The local airport monitoring method of present embodiment is at based on the monitoring center in the local airport monitoring system of multi-receiver, because in the present embodiment, after each receiver receives satellite data from visible satellite separately, it is not calculated, but only it is carried out analog to digital conversion, and directly will follow receiver information to send to monitoring center together through the satellite data after the analog to digital conversion, therefore, finish in monitoring center for the calculating of the pseudo-range corrections value of receiver.Wherein, the satellite data that receives of monitoring center comprises satellite (Geo-stationary Orbit; Hereinafter to be referred as GEO) navigation information that the WAAS information broadcast and gps satellite are broadcast, the receiver information that receiver sends then comprises the satellite elevation angle value of the visible satellite j of receiver i correspondence

Actual distance between receiver i and its visible satellite j

And the visible satellite number N of each receiver etc., monitoring center calculates the pseudo-range corrections value of corresponding every the satellite of each receiver according to the satellite data that receives.

What need indicate is, because the distance between each receiver on ground is very near, and the distance between the satellite and the earth is much far away by contrast, and therefore, both compare, and the distance between each receiver can be ignored fully.So, in embodiments of the present invention, can be similar to and think that the visible satellite number of each receiver is identical, and because the distance between each receiver is very near, therefore also can think the satellite elevation angle of each receiver approx for every visible satellite All equating, all is θ ^j

Particularly, the pseudo-range corrections value of receiver comprises three parts: pseudo-range corrections value, Wide Area Augmentation System pseudo-range corrections value and troposphere pseudo-range corrections value after Hatch filtering is level and smooth.Wherein, pseudo-range corrections value after Hatch filtering is level and smooth is meant that monitoring center extracts the pseudorange observed reading and the carrier phase observation data of position location satellite from the satellite data that receives, utilize the method for Hatch filtering then, with carrier phase observation data the pseudorange observed reading is carried out smoothly, obtain level and smooth after the pseudo-range corrections value; Wide Area Augmentation System pseudo-range corrections value comprises quick corrected value, long-term corrected value and ionosphere corrections value for to obtain the pseudo-range corrections value from the WAAS broadcast message that the GEO satellite is broadcast; And troposphere pseudo-range corrections value is the corrected value that carries out at tropospheric error, specifically is meant the pseudo-range corrections value by adopting the tropospheric error Model Calculation to obtain, and tropospheric error model herein is a Sa phase Ta Moning model.

Step 101, optional one receives the long-pending pseudo-airborne user of being, calculates the airborne user's of described puppet pseudo-range corrections value positioning error, and extract the airborne user's of described puppet Wide Area Augmentation System information distributing positioning error from described pseudo-range corrections value positioning error;

In the present embodiment, suppose that ground has M receiver, from M receiver, choose a receiver arbitrarily, it is assumed to " pseudo-airborne user ", as its name suggests, should " pseudo-airborne user " airborne user for supposing in the monitoring station on ground.Because in Civil Aviation System; the receiver on ground is compared with the distance of their relative satellites with the distance between the airborne user of reality; almost can ignore; therefore; can be similar to the error of thinking between 2 and have concomitant characteristics, so then can in protected level computing, be embodied " the pseudo-airborne user " that from receiver, choose arbitrarily at the computing of the airborne user's of reality protected level.And in computation process to the airborne user's of this puppet ground monitoring protected level; not only considered the error that the pseudo-range corrections value causes; considered that also monitoring center is for the airborne user's of reality ionosphere, the error that the troposphere causes; the gap of energy maximized further ground monitoring protected level and actual airborne user's protected level makes and monitors to such an extent that the result is more accurate.

In this step, the main error that the airborne user's of puppet pseudo-range corrections value is caused is calculated and is estimated.Error for the pseudo-airborne user's who selects pseudo-range corrections value, if ignore the measuring error of actual position, then this error mainly comes from two parts: the one, and the supervision error of receiver, mainly thermonoise and the multipath by ground causes, and is referred to as receiver and monitors error; The error that another information that is WAAS broadcasts is brought is referred to as Wide Area Augmentation System information distributing error, i.e. WAAS information distributing error.Therefore monitoring center will be at first according to the standard deviation sigma of this two parts error _MonAnd σ _MWAAS, utilize the variance transfer principle, calculate the standard deviation sigma of pseudo-range corrections value error _DPR, then according to the predefined continuity requirements of airborne user, the statistic algorithm by Gaussian distribution calculates continuity dilution of precision K _Mt, this continuity dilution of precision taken into full account since to the flase drop of system cause to the successional influence of system, last according to calculating pseudo-range corrections value error criterion difference σ _DPRWith continuity dilution of precision K _Mt, utilize described pseudorange territory to obtain pseudo-airborne user's pseudo-range corrections value positioning error to the transform matrix calculations of locator field.The WAAS information distributing positioning error of extracting the pseudo-airborne user who obtains from this pseudo-range corrections value positioning error then is the part of pseudo-airborne user's ground monitoring protected level.

Step 102, according to the transition matrix of pseudorange territory to locator field, calculate the airborne user's of described puppet surveillance positioning error, and described surveillance positioning error and described Wide Area Augmentation System information distributing positioning error sum carried out the calculating of desirable envelope value, obtain the airborne user's of described puppet ground monitoring protected level;

Because in the present embodiment; core concept to the calculating of ground monitoring and protecting level is: the airborne user's of reality protected level is calculated in the calculating that is transformed into the protected level of ground monitoring center; promptly be transformed in the calculating to the airborne user's of puppet protected level; therefore; in the computation process of the value of this protected level; have to consider of the influence of the error of each side to this ground monitoring protected level; particularly; comprise the error that information that following four part: WAAS broadcast causes; the error that the thermonoise of airboarne receiver and fuselage multipath cause; the ionospheric error that causes from the cross component in the monitoring center sky on ground, and the tropospheric error that causes from the vertical component at ground monitoring station.Wherein, the error that the information that WAAS broadcasts causes, be that WAAS information distributing error can monitor that positioning error obtains by subtraction calculations by pseudo-range corrections value positioning error and the receiver that step 101 calculates, therefore in this step, it mainly is the positioning error that calculates other three parts, in embodiments of the present invention, because all being each factor by surveillance, this three fractional error causes, as airborne user's the factor itself or the factor of monitoring center, the positioning error of therefore being referred to as this three part is the surveillance positioning error.

Calculating for this surveillance placement error value, at first, monitoring center will obtain the pseudorange territory standard deviation of every fractional error in the surveillance error according to the receiver information calculations, utilize the transition matrix of pseudorange territory again to locator field, the locator field standard deviation of vertical direction to of converting respectively, and utilizing the variance transfer principle, the localization criteria that calculates the monitoring system error is poor; Then, monitoring center will be according to the integrity value-at-risk of systemic presupposition, and the statistic algorithm by Gaussian distribution calculates integrity dilution of precision K _Bnd, to compare with the integrity value-at-risk that existing systems is default, in the present embodiment, this integrity dilution of precision has also been considered the influence of WAAS fault to whole LAM system; At last, monitoring center is according to the localization criteria difference and the integrity dilution of precision K that calculate the monitoring system error _Bnd, utilize the pseudorange territory to obtain pseudo-airborne user's surveillance positioning error, another part of the ground monitoring protected level that this surveillance positioning error is airborne user to the transform matrix calculations of locator field.

In the present embodiment; after monitoring center obtains WAAS information distributing positioning error and surveillance positioning error respectively by calculating; both sums that family calculates then are total positioning error of pseudo-airborne user's reality; and on this basis; total positioning error of this reality is carried out the calculating of further desirable envelope value; to obtain pseudo-airborne user's ground monitoring protected level at last, obtain best usable satellite combination in the heart by then can in ground monitoring, judging to the detection of this ground monitoring protected level.

Step 103; the ground monitoring protected level of all visible satellites combination of the airborne user of described puppet and the alarm limit value of airborne user preset are compared; obtain the combination of best usable satellite according to comparative result, and should the combination of the best usable satellite and the combination of this usable satellite in the pseudo-range corrections value of every visible satellite send to airborne user.

Particularly, monitoring center is divided into a plurality of satellite subclass by repeating query removal method with all visible satellites of the airborne user of puppet, at first all visible satellites of the airborne user of puppet are formed a set, be referred to as first order satellite subclass, judge whether the visible satellite number in this first order satellite subclass equals 4, if equal 4, then stop division to subclass, otherwise, from described set, remove a satellite respectively according to preset order, generate second level satellite subclass, the preset order of indication can be the data of the satellite after arranging according to the elevation angle ascending order of satellite herein, the implication of Qu Chuing is each wherein satellite of only removing respectively, rather than remove successively, suppose that promptly all visible satellite numbers are N, when removing first satellite, residue is N-1 in the combinations of satellites, when removing second satellite, add to first satellite removing in the combinations of satellites again, still remain N-1 in the combinations of satellites, judge whether the visible satellite number in the satellite subclass of the second level equals 4 this moment again, if the visible satellite number that is comprised in the satellite subclass of the second level equals at 4 o'clock, then stop division equally to subclass, if the visible satellite number that is comprised in the satellite subclass of the second level was greater than 4 o'clock, then continue to divide the satellite subclass according to the method, generate new N level satellite subclass, the number of the visible satellite in N level satellite subclass equals till 4.Suppose that dividing the last satellite number of subsets that obtains by this repeating query removal method is B, B can be by formula: $B=C_N^N+C_N^{N-1}+...+C_N^5+C_N^4$ Calculate, wherein N is all visible satellite numbers of pseudo-airborne user.

Divided after the subclass of visible satellite; the ground monitoring protected level of all satellite subclass of pseudo-airborne user will calculate in monitoring center; and the ground monitoring protected level of described satellite subclass compared with the alarm limit value of user preset successively; if the ground monitoring protected level of subclass is arranged less than described alarm limit value; the pseudo-range corrections value that then will comprise every visible satellite in the subclass of the maximum visible satellite of number of satellite and this subclass sends to airborne user, and this subclass that comprises the maximum visible satellite of number of satellite then is best visible satellite combination.

Present embodiment provides a kind of local airport monitoring method; by airborne user being carried out the detection of the error that sum of errors surveillance that the pseudo-range corrections value causes causes in the monitoring side on ground; and definition obtains the notion of ground monitoring protected level in view of the above; airborne user's self protected level calculating is transformed in the calculating of monitoring center to ground monitoring and protecting level on ground; thereby by choosing the best visible satellite combination of airborne user finished in the detection of the protected level of ground inspection center; oneself carry out the method for satellite subclass selection compares with airborne user in the existing system; when guaranteeing system accuracy; also improved the robustness of system; reduce airborne user's computation burden, improved real-time.

Fig. 2 is the process flow diagram of local airport monitoring method embodiment two of the present invention, and as shown in Figure 2, this enforcement local airport monitoring method comprises:

Step 200 is obtained the receiver information of each receiver itself and receiver from the satellite data that Navsat receives, and calculates the pseudo-range corrections value PR of every visible satellite of each receiver correspondence according to described satellite data _i ^j

This step 200 is the same with step 100 operation among the embodiment one, receives the satellite data that each receiver sends, and obtains the pseudo-range corrections value of receiver.Particularly, for j visible satellite of i receiver, its pseudo-range corrections value can be represented by following expression formula:

${\mathrm{PR}}_i^j=P_{\mathrm{Si}}^j+{\mathrm{PRC}}_i^j+{\mathrm{TC}}_i^j---\left(1\right)$

Wherein, P _Si ^jBe the pseudo-range corrections value after Hatch filtering is level and smooth, PRC _i ^jBe the pseudo-range corrections value that from the WAAS broadcast message, obtains, TC _i ^jBe troposphere pseudo-range corrections value.Particularly, monitoring center at first extracts the pseudorange observed reading P and the carrier phase observation data φ of position location satellite from the satellite data that receives, utilize the method for Hatch filtering then, with carrier phase observation data φ pseudorange observed reading P is carried out smoothly, obtain the pseudo-range corrections value after Hatch filtering is level and smooth, Hatch filtering computing formula as shown in Equation (2):

$P_{\mathrm{Si}}^j\left(l\right)=\frac{1}{N_S}{P}_i^j\left(l\right)+\frac{N_s-1}{N_s}(P_{\mathrm{Si}}^j(l-1)+\mathrm{\φ}\left(l\right)-\mathrm{\φ}(l-1))---\left(2\right)$

In the formula, l represents epoch, τ _sBe time constant filter, T _SFor measuring at interval N _sBe filter length: $N_s=\frac{{\mathrm{\τ}}_s}{T_s},$ P (l) is the l pseudo-range measurements of epoch, and φ (l) is the l carrier phase measurement value of epoch, P _S(l-1) be the pseudo-range corrections value of l-1 epoch after Hatch filtering is level and smooth.

Pseudorange observed reading P will reach the purpose of removing noise after Hatch filtering is level and smooth, at this moment, the pseudorange value that obtains from the WAAS broadcast message is proofreaied and correct again, and obtain WAAS pseudo-range corrections value PRC _i ^j, this WAAS pseudo-range corrections value also comprises three quick corrected value FC of part: WAAS _i ^j, the long-term corrected value LTC of WAAS _i ^jWith WAAS ionosphere corrections value IC _i ^j, the value of each part wherein can calculate according to the specifying information that provides in the WAAS text type.PRC _i ^jCalculation expression as follows:

${\mathrm{PRC}}_i^j={\mathrm{FC}}_i^j+{\mathrm{LTC}}_i^j+{\mathrm{IC}}_i^j---\left(3\right)$

Calculate troposphere pseudo-range corrections value TC at last _i ^jIn the present embodiment, monitoring center is in the process to the correction pseudorange of satellite data, except the information of utilizing WAAS to broadcast, utilize outside Hatch filtering handles the sign indicating number pseudorange, also use the tropospheric error model that tropospheric error is also proofreaied and correct simultaneously, specifically refer to adopt the Sa Sitamoning model pseudorange information to be proofreaied and correct TC _i ^jComputing formula be:

${\mathrm{TC}}_i^j=N_r{h}_0\frac{{10}^{-6}}{\sqrt{0.002+\sin \left({\mathrm{\θ}}_i^j\right)}}(1-e^{-\mathrm{\Δh}/h_0})---\left(4\right)$

Wherein, N _rBe tropospheric refractive index, h ₀Be the troposphere height, extract in the navigation information that can from satellite data, comprise and obtain θ _i ^jBe the satellite elevation angle, the data that comprise in the receiver information for the receiver transmission, Δ h is the height of aircraft (being airborne user) apart from the monitoring center on ground, it can measuring according to reality.

Step 201 is to described pseudo-range corrections value PR _i ^jCarry out the correction of receiver and satellite distance error, obtain new pseudo-range corrections value dPR _i ^j

Because the position of each receiver is known, therefore, the actual distance R between its each receiver and the satellite _i ⁱCan be by calculating in receiver, receiver sends it to monitoring center, and monitoring center is according to this actual distance R _i ⁱPseudo-range corrections value PR with the receiver that calculates in the step 200 _i ^jCan further carry out the correction of receiver and satellite distance error, obtain new pseudo-range corrections value dPR the pseudo-range corrections value of receiver _i ^j, dPR _i ^jComputing formula be:

${\mathrm{dPR}}_i^j={\mathrm{PR}}_i^j-R_i^j---\left(4\right)$

Step 202, optional receiver is pseudo-airborne user, calculates pseudo-airborne user's pseudo-range corrections value positioning error, concrete computation process comprises:

Step 2021, optional receiver is pseudo-airborne user, calculates the airborne user's of this puppet pseudo-range corrections value error criterion difference σ _DPR

In the present embodiment, the error of pseudo-airborne user's pseudo-range corrections value is mainly from two parts: the error that the information that the supervision sum of errors WAAS of receiver broadcasts is brought, be called receiver and monitor sum of errors WAAS information distributing error, and suppose that it is 0 Gaussian distribution that this two-part error is all obeyed average, therefore, at first need calculate the standard deviation of this two parts error.

Supervision error criterion difference σ for receiver _Mon, can calculate by following formula:

${\mathrm{\σ}}_{\mathrm{mon}}\left({\mathrm{\θ}}^j\right)=\sqrt{\frac{{(a_0+a_1{e}^{-{\mathrm{\θ}}^j/{\mathrm{\θ}}_0})}^2}{M}}---\left(5\right)$

Wherein, a ₀, a ₁, θ ₀By the performance rate decision of receiver, specifically can be with reference to the standard RTCA DO-245A of RTCA, θ ^jBe the satellite elevation angle value, M is the number of receiver.

Broadcast the information error standard deviation for WAAS, can calculate by following computing formula:

${\mathrm{\σ}}_{\mathrm{MWAAS}}\left({\mathrm{\θ}}_i^j\right)=0.26\·\mathrm{OF}\left({\mathrm{\θ}}_i^j\right)=0.26\·{[1-{\left(\frac{R_e\cos {\mathrm{\θ}}_i^j}{R_e+h_I}\right)}^2]}^{-\frac{1}{2}}---\left(6\right)$

Wherein, OF is the ionosphere tilt factor, R _eBe earth radius, h _IBe layer height.

And pseudo-range corrections value error criterion difference σ _DPRThen can obtain according to the variance transfer principle:

${\mathrm{\σ}}_{\mathrm{dPR}}\left({\mathrm{\θ}}_i^j\right)=\sqrt{{\mathrm{\σ}}_{\mathrm{mon}}^2\left({\mathrm{\θ}}_i^j\right)+{\mathrm{\σ}}_{\mathrm{MWAAS}}^2\left({\mathrm{\θ}}_i^j\right)}---\left(7\right)$

Step 2022 is calculated continuity dilution of precision K according to the predefined continuity requirements of airborne user _Mt

In order to guarantee the continuity of system, the continuity dilution of precision in the pseudo-range corrections value error is relevant with the continuity of system.And owing to cause that the Loss of continuity of system generally comprises two aspects: perhaps because of the real system failure, as satellite failure or land station's fault; Perhaps because of the flase drop to fault, therefore, the simple processing down can be to half distribution according to the continuity demand of user preset of above-mentioned two kinds of reasons, and the continuity demand of supposing user preset is P _r(continuity):

P _{Flase drop}=Pr (continuously)/2 (8)

For M receiver, the single-receiver emergency protection level of arbitrary receiver fault correspondence all might cause Loss of continuity, therefore; conservative consideration; all single-receiver emergency protection levels are for independently, so the probability of non-fault flase drop can determine divided by M by overall continuity demand, promptly

P _FD/M=P _{Flase drop}/ M (9)

Above-mentioned probability supposes that for a receiver this receiver visible satellite number is N, and then for the measured value of every satellite correspondence, its probability of false detection is:

P _FFD＝P _FFD/M/N (10)

So the continuity dilution of precision that finally obtains is:

K _mt＝Q ^-1(P _FFD/2) (11)

Wherein, $Q\left(x\right)=\frac{1}{\sqrt{2\mathrm{\&pi;}}}{\&Integral;}_x^{\&infin;}{e}^{-\frac{{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">t</figure-callout>}}^2}{2}}\mathrm{dt}.$

Step 2023 according to above-mentioned pseudo-range corrections value error criterion difference and continuity dilution of precision, calculates described pseudo-range corrections value positioning error E _k

In order to obtain higher monitoring efficient, the pseudorange territory that monitoring center utilizes position location satellite usually is converted into positioning error to the transition matrix S of locator field with pseudorange error, and the concrete computing method of this transition matrix S are shown below:

S＝(H ^TW ^-1H) ^-1H ^TW ^-1 (12)

Wherein, H represents the geometric matrix of position location satellite, by satellite position and receiver location decision, W is weights, the diagonal matrix that it is made up of the receiver standard deviation of position location satellite can be with reference to the standard RTCA DO-245 of RTCA about the detailed calculated formula of these two parameters.

And transition matrix S is that four lines (is represented x respectively, y, z, t) N _kRow, N _kBe the number of the visible satellite of the airborne user's correspondence of puppet, S _{J, vert}The z of representing matrix is capable.Because in civil aviaton uses, the requirement of vertical direction is more than in the horizontal direction requirement harshness, therefore, to error when the pseudorange territory is transformed into locator field, in the present embodiment, only consider the situation of vertical direction, the threshold value of the pseudo-range corrections value positioning error that obtains at last can be calculated by following formula:

${\mathrm{TE}}_{\mathrm{vert},k}=K_{\mathrm{mt}}\sqrt{\underset{j=1}{\overset{N_k}{\mathrm{\&Sigma;}}}{S}_{j,\mathrm{<figure-callout\; id="2"\; label="vert"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">vert</figure-callout>}}^2{\mathrm{\&sigma;}}_{\mathrm{dPR}}^2\left({\mathrm{\&theta;}}^j\right)}---\left(13\right)$

By above-mentioned steps, monitoring center just detects and calculates the error that the pseudo-range corrections value of the airborne user's of puppet receiver end causes, has obtained the threshold value of pseudo-range corrections value positioning error that should the airborne user of puppet, i.e. the maximal value of this error.

Step 2024 extracts pseudo-airborne user's Wide Area Augmentation System information distributing positioning error E from pseudo-range corrections value positioning error _{WAAS, k}

Because pseudo-range corrections value positioning error is to monitor positioning error E by receiver _{Mon, k}With WAAS information distributing positioning error E _{WAAS, k}Dimerous, from pseudo-range corrections value positioning error E _kIn extract pseudo-airborne user's Wide Area Augmentation System information distributing error E _{WAAS, k}The time, need be from pseudo-range corrections value positioning error E _kIn deduct receiver and monitor positioning error E _{Mon, k}

Step 203 is calculated pseudo-airborne user's surveillance positioning error, and concrete computation process comprises:

Step 2031, each the surveillance error criterion that calculates pseudo-airborne user is poor;

For the airborne user of reality, usually the total error that needs to consider mainly comprises the error that information that four part: WAAS broadcast causes, the error that the thermonoise of airboarne receiver and fuselage multipath cause, the ionospheric error that causes from the cross component at ground monitoring center, and the tropospheric error that causes from the vertical component at ground monitoring center.Therefore in the present embodiment, in the calculating to the airborne user's of puppet ground monitoring positioning error, also the positioning error that mainly causes from these four aspects is considered.In the present embodiment, because the singularity that above-mentioned said civil aviaton uses, the requirement of vertical direction is more than in the horizontal direction requirement harshness, therefore, also only considers the situation of vertical direction at this, and the pseudo-airborne user's who obtains thus total error expression formula is:

E _{total，vert，k}＝E _{MWAAS，vert，k}+E _{air，vert，k}+E _{iono，vert，k}+E _{trop，vert，k} (14)

Wherein, suppose:

E _{other，vert，k}＝E _{air，vert，k}+E _{iono，vert，k}+E _{trop，vert，k} (15)

And the error E that the information that WAAS broadcasts causes _{MWAAS, vert, k}Can calculate by step 204, therefore obtain:

E _{total，vert，k}＝E _vert，k-E _{mon，vert，k}+E _{other，vert，k} (16)

So far, the calculating of the airborne user's of puppet total error has been become the calculating of above-mentioned three parts, wherein, the pseudo-range corrections value positioning error E of first _{Vert, k}In step 203, calculate, and the supervision of second portion receiver is decided to be error E _{Mon, vert, k}Obeying average is 0, and standard deviation is σ _MonGaussian distribution, and this standard deviation sigma _MonIn formula (5), obtained calculating, therefore, in this step, should be at first to E _{Other, vert, k}In the standard deviation of three fractional errors that comprise calculate.

Particularly, the thermonoise and the fuselage multipath error standard deviation sigma of the error that causes for airborne user's itself thermonoise and fuselage multipath _{Air, vert, j}The ionospheric error standard deviation sigma of the ionospheric error that causes with the cross component at ground monitoring station _{Iono, vert, j}, its detailed computing formula all can be with reference to the standard RTCA DO-245 of RTCA, and is specific as follows:

${\mathrm{\&sigma;}}_{\mathrm{air},\mathrm{vert},j}=\sqrt{{\mathrm{\&sigma;}}_{\mathrm{air}\_\mathrm{<figure-callout\; id="2"\; label="noise"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">noise</figure-callout>}}^2+{\mathrm{\&sigma;}}_{\mathrm{air}\_\mathrm{<figure-callout\; id="2"\; label="multipath"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">multipath</figure-callout>}}^2}=\sqrt{{(0.11+0.13\&times;e^{\frac{{\mathrm{\&theta;}}^j}{4}})}^2+{(0.13+0.53\&times;e^{-\frac{{\mathrm{\&theta;}}^j}{10}})}^2}---\left(17\right)$

σ _{iono，vert，j}＝0.106×OF(θ ^j) (18)

Wherein, OF is the ionosphere tilt factor, θ ^jBe the satellite elevation angle value.

And the tropospheric error standard deviation sigma that causes for the vertical component at ground monitoring station _{Tropo, vert, j}, because with respect to σ _{Air, vert, j}And σ _{Iono, vert, j}, σ _{Tropo, vert, j}Value very little, so approx:

σ _{tropo，vert，j}＝0 (19)

Step 2032 is calculated integrity dilution of precision K according to the integrity value-at-risk of systemic presupposition _Bnd

Owing to when calculating pseudo-airborne user's surveillance positioning error, think that approx this error is an ideal value, promptly think the error E that information that WAAS broadcasts causes _{MWAAS, vert, k}, the error E that the thermonoise of airboarne receiver and fuselage multipath cause _{Air, vert, k}, the ionospheric error E that causes from the cross component at ground monitoring station _{Iono, vert, k}, and the tropospheric error E that causes from the vertical component at ground monitoring station _{Trop, vert, k}All be to calculate under the assumed condition of Gaussian distributed, therefore, in the computation process of surveillance positioning error, must consider that the LAM system is the integrity value-at-risk that vertical protected level distributes, this value-at-risk is specifically by integrity error factor K _BndReflect, particularly, K _BndComputing formula be:

K _Bnd=Q ^-1(P _Integrity) (20)

Wherein, $Q\left(x\right)=\frac{1}{\sqrt{2\mathrm{\&pi;}}}{\&Integral;}_x^{\&infin;}{e}^{-\frac{{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">t</figure-callout>}}^2}{2}}\mathrm{dt},$ P _IntegrityExpression multi-receiver LAM system is the integrity value-at-risk that vertical protected level distributes, and is specially 8.5e-8, with the P in the existing algorithm _IntegrityFor 2.5e-8 compares, this value of present embodiment has also been further considered the influence of WAAS fault to the LAM system.

Step 2033, poor according to above-mentioned integrity dilution of precision and each surveillance error criterion, calculate the surveillance positioning error;

In the present embodiment, in order to obtain higher monitoring efficient, surveillance error criterion difference can be obtained by the transition matrix S conversion of pseudorange territory to locator field by the standard deviation in pseudorange territory:

${\mathrm{\&sigma;}}_{\mathrm{air},\mathrm{vert},k}=\sqrt{\underset{j=1}{\overset{N_k}{\mathrm{\&Sigma;}}}{S}_{j,\mathrm{<figure-callout\; id="2"\; label="vert"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">vert</figure-callout>}}^2{\mathrm{\&sigma;}}_{\mathrm{air},\mathrm{vert},\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">j</figure-callout>}}^2}$

${\mathrm{\&sigma;}}_{\mathrm{iono},\mathrm{vert},k}=\sqrt{\underset{j=1}{\overset{N_k}{\mathrm{\&Sigma;}}}{S}_{j,\mathrm{<figure-callout\; id="2"\; label="vert"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">vert</figure-callout>}}^2{\mathrm{\&sigma;}}_{\mathrm{iono},\mathrm{vert},j}^2}---\left(21\right)$

${\mathrm{\&sigma;}}_{\mathrm{tropo},\mathrm{vert},k}=\sqrt{\underset{j=1}{\overset{N_k}{\mathrm{\&Sigma;}}}{S}_{j,\mathrm{<figure-callout\; id="2"\; label="vert"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">vert</figure-callout>}}^2{\mathrm{\&sigma;}}_{\mathrm{tropo},\mathrm{vert},\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">j</figure-callout>}}^2}$

Definition σ _{Other, vert, k}Be the summation of above-mentioned three kinds of standard deviations, can obtain by the variance transfer principle:

${\mathrm{\&sigma;}}_{\mathrm{other},\mathrm{vert},k}=\sqrt{{\mathrm{\&sigma;}}_{\mathrm{air},\mathrm{vert},\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">k</figure-callout>}}^2+{\mathrm{\&sigma;}}_{\mathrm{iono},\mathrm{vert},\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">k</figure-callout>}}^2+{\mathrm{\&sigma;}}_{\mathrm{tropo},\mathrm{vert},k}^2}---\left(22\right)$

In addition, owing in calculating, comprise that also receiver monitors positioning error E to total positioning error of the airborne user of puppet _{Mon, vert, k}, and this receiver monitors positioning error E _{Mon, vert, k}With surveillance positioning error E _{Other, vert, k}Therefore the Gaussian distribution of all obey average be 0, in the ideal case, can carry out both the calculating of envelope value, and particularly, above-mentioned formula (16) can be exchanged into:

VPL _ideal，k＝|E _vert，k|+K _bndσ _{mon+other，vert，k} (23)

Wherein, with pseudo-range corrections value positioning error E _{Vert, k}Taking absolute value also is in order to obtain maximal value ideally, and, according to variance transfer principle, σ _{Mon+other, vert, k}Can calculate by following formula:

${\mathrm{\&sigma;}}_{\mathrm{mon}+\mathrm{other},\mathrm{vert},k}=\sqrt{{\mathrm{\&sigma;}}_{\mathrm{mon},\mathrm{vert},\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">k</figure-callout>}}^2+{\mathrm{\&sigma;}}_{\mathrm{other},\mathrm{vert},k}^2}---\left(24\right)$

Step 2034 calculates pseudo-airborne user's ground monitoring protected level VPL _{Mon, k}

Since in the formula (23) with pseudo-range corrections value positioning error E _{Vert, k}Take absolute value, be the threshold T E of the pseudo-airborne user's that formula (13) obtains pseudo-range corrections value positioning error _{Vert, k}, the ground monitoring protected level that finally can obtain pseudo-airborne user is:

${\mathrm{VPL}}_{\mathrm{mon},k}=K_{\mathrm{mt}}\sqrt{\underset{j=1}{\overset{N_k}{\mathrm{\&Sigma;}}}{S}_{j,\mathrm{<figure-callout\; id="2"\; label="vert"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">vert</figure-callout>}}^2{\mathrm{\&sigma;}}_{\mathrm{dPR}}^2\left({\mathrm{\&theta;}}^j\right)}+K_{\mathrm{bnd}}{\mathrm{\&sigma;}}_{\mathrm{mon}+\mathrm{other},\mathrm{vert},k}---\left(25\right)$

Step 204, the ground monitoring protected level of all visible satellites combination of the airborne user of puppet is compared with the alarm limit value of airborne user preset successively, if the ground monitoring protected level of visible satellite combination is less than described alarm limit value, then execution in step 205, if the ground monitoring protected level of all visible satellite combinations then carries out 206 all greater than described alarm limit value;

Particularly; in this step; all visible satellites to the airborne user of puppet are at first carried out the division of visible satellite subclass by repeating query removal method; carry out the calculating of the ground monitoring protected level of each subclass again at each visible satellite subclass; the process of concrete division visible satellite subclass is described in detail in embodiment one, does not repeat them here.Each visible satellite subclass for the airborne user of puppet; the value of its ground monitoring protected level may be greater than the alarm limit value of airborne user preset; also may be less than this alarm limit value; when less than the alarm limit value of user preset; representing the visible satellite combination of this subclass is available for airborne user; and when its ground monitoring protected level during greater than the alarm limit value of airborne user preset; then representing the visible satellite combination of this subclass is disabled for airborne user, and then this subclass should be given up.

Step 205, the pseudo-range corrections value that will comprise every visible satellite in maximum visible satellite combination of number of satellite and the combination of this visible satellite sends to airborne user;

If the value of pseudo-airborne user's ground monitoring protected level is during greater than airborne user's alarm limit value; representing the visible satellite combination of this subclass is available for airborne user; then this visible satellite combination should be sent to airborne user; but; usually; for the many more combinations of satellite number; its monitoring and protecting level is more little; for airborne user; the monitoring and protecting level is more little; represent airborne user's error more little, therefore, airborne user should select the maximum visible satellite combination of number of satellite.And in the present embodiment; come visible satellite combination is selected by monitoring center; direct comparative result according to ground monitoring and protecting level and alarm limit value; the pseudo-range corrections value that will comprise every visible satellite in maximum visible satellite combination of number of satellite and the combination of this visible satellite directly sends to airborne user, has reduced airborne user's computation burden.

Step 206 sends the disabled warning information of indication this satellite navigation system of airborne user to described airborne user.

If the ground monitoring protected level that all visible satellite combination calculation of pseudo-airborne user obtain is during all greater than described alarm limit value; represent all combinations of satellites of airborne user all unavailable; monitoring center then will send a warning message to airborne user, and it is disabled state that this warning information is indicated the current satellite navigation system of airborne user.

Present embodiment provides a kind of local airport monitoring method; on basis based on multi-receiver; by airborne user being carried out the detection of the error that sum of errors surveillance that the pseudo-range corrections value causes causes in the monitoring side on ground; and definition obtains the notion of ground monitoring protected level in view of the above; airborne user's self protected level calculating is transformed in the calculating of monitoring center to ground monitoring and protecting level on ground; thereby by choosing the best visible satellite combination of airborne user finished in the detection of the protected level of ground measuring station; oneself carry out the method for satellite subclass selection compares with airborne user in the existing system; when guaranteeing system accuracy; also improved the robustness of system; reduced airborne user's computation burden; improved real-time; further; in the computation process to ground monitoring and protecting level in the present embodiment; also taken into full account the influence of tropospheric error to it; and the continuity loss that brings of the error of integrity monitoring and WAAS fault make that to the influence of LAM system the calculating of this protected level is more accurate.

One of ordinary skill in the art will appreciate that: all or part of step that realizes said method embodiment can be finished by the relevant hardware of programmed instruction, aforesaid program can be stored in the computer read/write memory medium, this program is carried out the step that comprises said method embodiment when carrying out; And aforesaid storage medium comprises: various media that can be program code stored such as ROM, RAM, magnetic disc or CD.

Fig. 3 is the structural representation of local airport monitoring device embodiment of the present invention, and as shown in Figure 3, local airport monitoring device of the present invention comprises:

First computing module 11, be used to obtain receiver information of each receiver itself and the satellite data that receiver receives from Navsat, the enhancing information, carrier phase observation data and the tropospheric error model that utilize Wide Area Augmentation System to broadcast are proofreaied and correct the pseudorange information in the described satellite data, obtain the pseudo-range corrections value of every satellite of each receiver correspondence, described receiver information comprises the actual distance between satellite elevation angle value, receiver and its visible satellite of the visible satellite of receiver correspondence and the visible satellite number of each receiver;

Second computing module 12, be connected with described first computing module 11, being used for optional receiver is pseudo-airborne user, according to the airborne user's of described puppet the described receiver information and the continuity requirements of airborne user preset, utilize the pseudorange territory to obtain the airborne user's of described puppet pseudo-range corrections value positioning error, and from described pseudo-range corrections value positioning error, extract the airborne user's of described puppet Wide Area Augmentation System information distributing positioning error to the transform matrix calculations of locator field;

The 3rd computing module 13, be connected with described second computing module 12, be used for according to the airborne user's of described puppet the described receiver information and the integrity value-at-risk of systemic presupposition, utilize described pseudorange territory to obtain the airborne user's of described puppet surveillance positioning error to the transform matrix calculations of locator field, and described surveillance positioning error and described Wide Area Augmentation System information distributing error sum carried out the calculating of desirable envelope value, obtain the airborne user's of described puppet ground monitoring protected level, described surveillance positioning error comprises the positioning error that is caused by airborne user's thermonoise and fuselage multipath, the positioning error that the positioning error that is caused by the ionosphere in the monitoring center sky and the troposphere in the monitoring center sky cause;

Judging module 14; be connected with described the 3rd computing module 13; be used for the ground monitoring protected level of all visible satellites combination of the airborne user of described puppet is compared with the alarm limit value of airborne user preset successively; if, then will comprising the pseudo-range corrections value of every visible satellite in maximum visible satellite combination of number of satellite and the combination of this visible satellite less than described alarm limit value, the ground monitoring protected level of described visible satellite combination sends to described airborne user.

Particularly, this local airport monitoring device is arranged on the monitoring center end of local airport monitoring system, and its concrete observation process describes in detail in the embodiment of above-mentioned local airport monitoring method, no longer gives unnecessary details at this.

The embodiment of the invention provides a kind of local airport monitoring device; by airborne user being carried out the detection of the error that sum of errors surveillance that the pseudo-range corrections value causes causes in the monitoring side on ground; and definition obtains the notion of ground monitoring protected level in view of the above; airborne user's self protected level calculating is transformed in the calculating of monitoring center to ground monitoring and protecting level on ground; thereby by choosing the best visible satellite combination of airborne user finished in the detection of the protected level of ground measuring station; oneself carry out the method for satellite subclass selection compares with airborne user in the existing system; when guaranteeing system accuracy; also improved the robustness of system; reduce airborne user's computation burden, improved real-time.

Fig. 4 is the structural representation of local airport monitoring system embodiment of the present invention, and as shown in Figure 4, local airport monitoring system of the present invention comprises:

A plurality of receivers 1, be used to receive the satellite data that Navsat sends, described satellite data is carried out analog to digital conversion, and satellite data that will be after digital-to-analog conversion and the receiver information of himself sends to monitoring center, and described receiver information comprises the actual distance between satellite elevation angle value, receiver and its visible satellite of the visible satellite of receiver correspondence and the visible satellite number of each receiver;

One monitoring center 2, be connected with described receiver 1, be used for calculating the pseudo-range corrections value of every satellite of described receiver correspondence according to the satellite data that receives, and the error that the sum of errors surveillance that airborne user's pseudo-range corrections value is caused according to described receiver information causes detects, calculate the ground monitoring protected level of described monitoring center, and by big or small comparative result to the alarm limit value of described ground monitoring protected level and user preset, obtain available combinations of satellites, the pseudo-range corrections value of every visible satellite in described available combinations of satellites and this combinations of satellites is sent to airborne user;

Particularly, this monitoring center can be provided with the local airport monitoring device in the foregoing description, and all of this monitoring center can be realized by this local airport monitoring device the concrete computation process and the monitoring operation of satellite data, the concrete composition module and the function of this local airport monitoring device all describe in detail in the above-described embodiments, no longer set forth at this.

One airborne user 3 is connected with described monitoring center 2, the position that the pseudo-range corrections value that visible satellite makes up and visible satellite makes up that is used for sending according to described monitoring center is calculated described airborne user.

Particularly, in advancing near procedure, be similar to and think that airborne user is identical with the visible satellite at ground monitoring station, because airborne user's position is higher, so more than the visible satellite number at ground monitoring station, " give up unnecessary satellite " possibly by this moment for its visible satellite number.Airborne user utilizes the subclass of " the best " combinations of satellites that the ground monitoring station sends and the pseudo-range corrections value of each satellite, carries out the calculating of protected level, and obtains described airborne user's position according to result of calculation.Protected level for airborne user calculates; the pseudo-range corrections value of the visible satellite that it can provide according to monitoring center is calculated; and this pseudo-range corrections value is represented with the Gaussian distribution of zero-mean the positioning error protected level of the vertical direction that obtains is thus calculated by following formula:

${\mathrm{VPL}}_{H0,k}=K_{\mathrm{ffmd}}\sqrt{\underset{j=1}{\overset{N_k}{\mathrm{\&Sigma;}}}{S}_{j,\mathrm{<figure-callout\; id="2"\; label="vert"\; filenames="H2009100885127E00032.png"\; state="\{\{state\}\}">vert</figure-callout>}}^2{\mathrm{\&sigma;}}_{\mathrm{dPR}}^2\left({\mathrm{\&theta;}}^j\right)+{\mathrm{\&sigma;}}_{\mathrm{other},\mathrm{vert},k}^2}---\left(26\right)$

Wherein, K _FfmdFor the non-fault omission factor, get fixed value 5.847.

The embodiment of the invention provides a kind of local airport monitoring system; by airborne user being carried out the detection of the error that sum of errors surveillance that the pseudo-range corrections value causes causes in the monitoring center on ground; and definition obtains the notion of ground monitoring protected level in view of the above; airborne user's self protected level calculating is transformed in the calculating of monitoring center to ground monitoring and protecting level on ground; thereby by choosing the best visible satellite combination of airborne user finished in the detection of the protected level of ground measuring station; oneself carry out the method for satellite subclass selection compares with airborne user in the existing system; when guaranteeing system accuracy; also improved the robustness of system; reduce airborne user's computation burden, improved real-time.

It should be noted that at last: above embodiment only in order to technical scheme of the present invention to be described, is not intended to limit; Although with reference to previous embodiment the present invention is had been described in detail, those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution break away from the spirit and scope of various embodiments of the present invention technical scheme.

Claims (9)

1. a local airport monitoring method is characterized in that, comprising:

Obtain receiver information of each receiver itself and the satellite data that receiver receives from Navsat, the enhancing information, carrier phase observation data and the tropospheric error model that utilize Wide Area Augmentation System to broadcast are proofreaied and correct the pseudorange information in the described satellite data, obtain the pseudo-range corrections value of every satellite of each receiver correspondence, described receiver information comprises the actual distance between satellite elevation angle value, receiver and its visible satellite of the visible satellite of receiver correspondence and the visible satellite number of each receiver;

Optional receiver is pseudo-airborne user, according to the airborne user's of described puppet the described receiver information and the continuity requirements of airborne user preset, utilize the pseudorange territory to obtain the airborne user's of described puppet pseudo-range corrections value positioning error, and from described pseudo-range corrections value positioning error, extract the airborne user's of described puppet Wide Area Augmentation System information distributing positioning error to the transform matrix calculations of locator field;

According to the airborne user's of described puppet the described receiver information and the integrity value-at-risk of systemic presupposition, utilize described pseudorange territory to obtain the airborne user's of described puppet surveillance positioning error to the transform matrix calculations of locator field, and described surveillance positioning error and described Wide Area Augmentation System information distributing positioning error sum carried out the calculating of desirable envelope value, obtain the airborne user's of described puppet ground monitoring protected level, described surveillance positioning error comprises the positioning error that is caused by airborne user's thermonoise and fuselage multipath, the positioning error that the positioning error that is caused by the ionosphere in the monitoring center sky and the troposphere in the monitoring center sky cause;

The ground monitoring protected level of all visible satellites combination of the airborne user of described puppet is compared with the alarm limit value of airborne user preset successively; if, then will comprising the pseudo-range corrections value of every visible satellite in maximum visible satellite combination of number of satellite and the combination of this visible satellite less than described alarm limit value, the ground monitoring protected level of described visible satellite combination sends to described airborne user.

2. local airport monitoring method according to claim 1, it is characterized in that, described according to the airborne user's of described puppet the described receiver information and the continuity requirements of airborne user preset, utilize the pseudorange territory to comprise to the pseudo-range corrections value positioning error that the transform matrix calculations of locator field obtains the airborne user of described puppet:

The supervision error criterion difference and the Wide Area Augmentation System that obtain the airborne user of described puppet according to described receiver information are broadcast the information error standard deviation, it is poor to utilize the variance transfer principle to calculate pseudo-range corrections value error criterion, the standard deviation during the error Gaussian distributed of the pseudo-range corrections value that described pseudo-range corrections value error criterion difference is the airborne user of described puppet;

According to the predefined continuity requirements of airborne user, the statistic algorithm by Gaussian distribution calculates the continuity dilution of precision;

According to described pseudo-range corrections value error criterion difference and described continuity dilution of precision, utilize the transition matrix of described pseudorange territory to locator field, calculate described pseudo-range corrections value positioning error.

3. local airport monitoring method according to claim 2 is characterized in that, the described Wide Area Augmentation System information distributing positioning error that extracts the airborne user of described puppet from described pseudo-range corrections value positioning error is specially:

The receiver that deducts the airborne user of described puppet from described pseudo-range corrections value positioning error monitors positioning error.

4. local airport monitoring method according to claim 3, it is characterized in that, described according to the airborne user's of described puppet the described receiver information and the integrity value-at-risk of systemic presupposition, utilize described pseudorange territory to comprise to the surveillance positioning error that the transform matrix calculations of locator field obtains the airborne user of described puppet:

Obtain the airborne user's of described puppet thermonoise and fuselage multipath error standard deviation, ionospheric error standard deviation and tropospheric error standard deviation according to described receiver information, it is poor to utilize the variance transfer principle to calculate the surveillance error criterion, the standard deviation when described thermonoise and fuselage multipath error standard deviation, ionospheric error standard deviation and tropospheric error standard deviation are respectively the airborne user's of described puppet thermonoise and fuselage multipath error, ionospheric error and tropospheric error Gaussian distributed;

According to the integrity value-at-risk of systemic presupposition, the statistic algorithm by Gaussian distribution calculates the integrity dilution of precision;

According to described surveillance error criterion difference and described integrity dilution of precision, utilize the transition matrix of described pseudorange territory to locator field, calculate described surveillance positioning error.

5. according to claim 1 or 4 described local airport monitoring methods, it is characterized in that the ground monitoring protected level of described all visible satellites combination with the airborne user of described puppet compares with the alarm limit value of airborne user preset successively and comprises:

All visible satellites of the airborne user of described puppet are divided into a plurality of satellite subclass by repeating query removal method, and the visible satellite number that described satellite subclass comprises is more than or equal to 4;

Calculate the ground monitoring protected level of each satellite subclass of the airborne user of described puppet, the ground monitoring protected level of described satellite subclass is compared with described alarm limit value successively.

6. local airport monitoring method according to claim 5 is characterized in that, described all visible satellites with the airborne user of described puppet are divided into a plurality of satellite subclass by repeating query removal method and comprise:

All visible satellites of the airborne user of described puppet are formed a first order satellite subclass, judge whether the visible satellite number in the described first order satellite subclass equals 4, if the visible satellite number that is comprised in the described first order satellite subclass equals 4, then stop division to the satellite subclass, otherwise, then from the described first satellite subclass, remove a satellite respectively, generate second level satellite subclass according to preset order;

Judge whether the visible satellite number in the satellite subclass of the described second level equals 4, if the visible satellite number that is comprised in the satellite subclass of the described second level equals 4, then stop division to the satellite subclass, otherwise, then in each second level satellite subclass, continue to remove a satellite, generate third level satellite subclass according to preset order;

And the like, the number of satellite that comprises in dividing the N level satellite subclass that generates equals till 4.

7. local airport monitoring method according to claim 6 is characterized in that, described method also comprises:

If the ground monitoring protected level of all visible satellite combinations of the airborne user of described puppet then sends the disabled warning information of the airborne user's satellite navigation system of indication to described airborne user all greater than described alarm limit value.

8. a local airport monitoring device is characterized in that, comprising:

First computing module, be used to obtain receiver information of each receiver itself and the satellite data that receiver receives from Navsat, the enhancing information, carrier phase observation data and the tropospheric error model that utilize Wide Area Augmentation System to broadcast are proofreaied and correct the pseudorange information in the described satellite data, obtain the pseudo-range corrections value of every satellite of each receiver correspondence, described receiver information comprises the actual distance between satellite elevation angle value, receiver and its visible satellite of the visible satellite of receiver correspondence and the visible satellite number of each receiver;

Second computing module, be connected with described first computing module, being used for optional receiver is pseudo-airborne user, according to the airborne user's of described puppet the described receiver information and the continuity requirements of airborne user preset, utilize the pseudorange territory to obtain the airborne user's of described puppet pseudo-range corrections value positioning error, and from described pseudo-range corrections value positioning error, extract the airborne user's of described puppet Wide Area Augmentation System information distributing positioning error to the transform matrix calculations of locator field;

The 3rd computing module, be connected with described second computing module, be used for according to the airborne user's of described puppet the described receiver information and the integrity value-at-risk of systemic presupposition, utilize described pseudorange territory to obtain the airborne user's of described puppet surveillance positioning error to the transform matrix calculations of locator field, and described surveillance positioning error and described Wide Area Augmentation System information distributing positioning error sum carried out the calculating of desirable envelope value, obtain the airborne user's of described puppet ground monitoring protected level, described surveillance positioning error comprises the positioning error that is caused by airborne user's thermonoise and fuselage multipath, the positioning error that the positioning error that is caused by the ionosphere in the monitoring center sky and the troposphere in the monitoring center sky cause;

Judging module; be connected with described the 3rd computing module; be used for the ground monitoring protected level of all visible satellites combination of the airborne user of described puppet is compared with the alarm limit value of airborne user preset successively; if, then will comprising the pseudo-range corrections value of every visible satellite in maximum visible satellite combination of number of satellite and the combination of this visible satellite less than described alarm limit value, the ground monitoring protected level of described visible satellite combination sends to described airborne user.

9. a local airport monitoring system is characterized in that, comprising:

A plurality of receivers, be used to receive the satellite data that Navsat sends, described satellite data is carried out analog to digital conversion, and satellite data that will be after analog to digital conversion and the receiver information of himself sends to monitoring center, and described receiver information comprises the actual distance between satellite elevation angle value, receiver and its visible satellite of the visible satellite of receiver correspondence and the visible satellite number of each receiver;

One monitoring center; be connected with described receiver; be used for calculating the pseudo-range corrections value of every satellite of described receiver correspondence according to the satellite data that receives; and the error that the sum of errors surveillance that airborne user's pseudo-range corrections value is caused according to described receiver information causes detects; calculate the ground monitoring protected level of described monitoring center; and by big or small comparative result to the alarm limit value of described ground monitoring protected level and user preset; obtain best visible satellite combination; the pseudo-range corrections value of every visible satellite in the combination of the visible satellite of described the best and this combinations of satellites is sent to airborne user

Described monitoring center comprises: first computing module, be used to obtain receiver information of each receiver itself and the satellite data that receiver receives from Navsat, the enhancing information of utilizing Wide Area Augmentation System to broadcast, carrier phase observation data and tropospheric error model are proofreaied and correct the pseudorange information in the described satellite data, obtain the pseudo-range corrections value of every satellite of each receiver correspondence, described receiver information comprises the satellite elevation angle value of the visible satellite of receiver correspondence, the actual distance between receiver and its visible satellite and the visible satellite number of each receiver;

Second computing module, be connected with described first computing module, being used for optional receiver is pseudo-airborne user, according to the airborne user's of described puppet the described receiver information and the continuity requirements of airborne user preset, utilize the pseudorange territory to obtain the airborne user's of described puppet pseudo-range corrections value positioning error, and from described pseudo-range corrections value positioning error, extract the airborne user's of described puppet Wide Area Augmentation System information distributing positioning error to the transform matrix calculations of locator field;

The 3rd computing module, be connected with described second computing module, be used for according to the airborne user's of described puppet the described receiver information and the integrity value-at-risk of systemic presupposition, utilize described pseudorange territory to obtain the airborne user's of described puppet surveillance positioning error to the transform matrix calculations of locator field, and described surveillance positioning error and described Wide Area Augmentation System information distributing positioning error sum carried out the calculating of desirable envelope value, obtain the airborne user's of described puppet ground monitoring protected level, described surveillance positioning error comprises the positioning error that is caused by airborne user's thermonoise and fuselage multipath, the positioning error that the positioning error that is caused by the ionosphere in the monitoring center sky and the troposphere in the monitoring center sky cause;

Judging module, be connected with described the 3rd computing module, be used for the ground monitoring protected level of all visible satellites combination of the airborne user of described puppet is compared with the alarm limit value of airborne user preset successively, if, then will comprising the pseudo-range corrections value of every visible satellite in maximum visible satellite combination of number of satellite and the combination of this visible satellite less than described alarm limit value, the ground monitoring protected level of described visible satellite combination sends to described airborne user;

One airborne user is connected with described monitoring center, is used for the position of calculating described airborne user according to the pseudo-range corrections value that best visible satellite makes up and visible satellite makes up that described monitoring center sends.

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