CN105116390A - Marine radar calibration-oriented measured value and AIS truth value dot pair construction method - Google Patents

Abstract

The invention discloses a marine radar calibration-oriented measured value and AIS truth value dot pair construction method. The technology relates to the field of marine radar error calibration, and available targets are screened for pairing, thereby building a target dot pair, and providing data support for subsequent error analysis. The method is realized mainly through the following technical scheme: first uniform GPS time service equipment is utilized to provide time service to marine radar equipment and AIS receiving equipment; then validity judgment is performed on an AIS message, preliminary screening is completed, space coordinate transformation is performed on AIS positioning data according to a radar antenna position, a screening area is set and radar targets are screened; then the screened radar targets are fed back to the AIS and further screening is performed, and the screening area is diminished according to a screening result till target pairing is completed; and finally, according to time of radar track data and a paired AIS target track of adjacent moments before and after the time of the radar track data, interpolation is performed on the AIS track, and an interpolation result and the radar track form a measured value and truth value dot pair.

Description

Towards the measured value of marine radar calibration and AIS true value point to construction method

One, technical field

The present invention relates to measured value in marine radar error calibration field and AIS true value point to building research direction, be utilize base station AIS equipment to receive real time data as target true value, carry out the data preprocessing phase of marine radar error calibration, carry out marine radar error analysis for follow-up Data support is provided, be applicable to the error calibration of the sea-surface target detection radar such as navigation, search, warning, Target indication under bank base and hip-based platform condition.

Two, background technology

AIS, i.e. automatic recognition system, it is the one communication answering equipment in order to assist VTS to use, the many equipment such as GPS locating information, VHF communication machine, display that are integrated with are in one, automatically report bit walk facility as a kind of boats and ships, self-organization time division multiple access (TDMA) access way Auto broadcast can be adopted and receive Ship dynamic situation, static state and the data relevant to navigation.Due to features such as the abundant information of AIS, the positioning precision with GPS and all weather operations, obtain a wide range of applications at navigational field.The boats and ships that International Maritime Organization's mandatory requirement was built after in July, 2000 must install AIS transponder.Along with the widespread use of AIS, researcher is had to propose to utilize base station AIS equipment to receive and the marine ships GPS locator data parsed, as true value position during marine radar calibration, and be directly a kind of GPS Calibration Method by utilizing the radar calibration method of AIS to regard as.When selecting the ship target of radar calibration from sea, generally need artificial screening, and need operating personnel to possess certain experience.AIS power range is generally wide than radar, and blind area little, be not easily disturbed, its advantage should be played screen radar target, but, if radar can not form effective detection to target, only there is the target of AIS data to be invalid, therefore, carry out the marking target screening that automatically hockets of AIS and radar and there is certain advantage.The existing AIS of utilization carries out the method for calibration to radar, generally only uses a kind of method when spatial alternation, but the measurement of radar to target range and orientation is separate, can separately resolve.At present, have no and towards the measured value of marine radar calibration and AIS true value point, the research of construction method is reported.

Three, summary of the invention

1. the technical matters that will solve

The object of the present invention is to provide a kind of can be applied to marine radar calibration measured value and AIS true value point to the method built, AIS target and radar target is utilized to hocket object filtering, complete radar and the pairing of AIS target, on this basis, based on marine radar range observation and the separate feature of measurement of bearing, calculate target range and target azimuth respectively, complete the spatial alternation of pairing targetpath data, and utilize AIS data transfer rate higher than the feature of radar data rate, linear interpolation is carried out to AIS track data, deadline aligns, form effective impact point pair, for subsequent implementation error analysis provides Data support.

2. technical scheme

Measured value towards marine radar calibration of the present invention and AIS true value point, to construction method, comprise the following steps:

(1) unified time service equipment is utilized to carry out time service to marine radar and AIS equipment, guarantee the time consistency of equipment, when receiving AIS message, by message authentication code, forwarding designator, accommodation degree of accuracy and electronic position-fixing device type four indicating bits, AIS message is filtered;

(2) the AIS position report message received is resolved, and carry out space coordinate transformation according to radar antenna gps data, be converted into the targetpath data of polar form, prime area thresholding is set, this thresholding is utilized to screen radar target, retain the radar target meeting region threshold condition, and match with AIS target, if there is multiple AIS target in the region thresholding of single radar target, then reduce thresholding size gradually according to stepping method, until all radar targets and AIS target one_to_one corresponding;

(3) radar that record object is right simultaneously and AIS data, wherein radar data record object lot number, distance, orientation, time, AIS data recording user identifier, longitude, latitude, time, according to radar antenna gps data, space coordinate transformation is carried out to the AIS data of record, packet after resolving is containing customer identification number, distance, orientation, time, get the AIS flight path being close to two moment before and after the target radar flight path moment, by the method for linear interpolation, calculate the AIS flight path in radar track moment, complete the time unifying that target is right, form radargrammetry value and AIS true value point pair.

3. beneficial effect

The present invention compares background technology and has following advantage:

(1) the method utilizes AIS and radar to hocket object filtering, while the effective destination number of guarantee, effectively can reduce the quantity of independent object;

(2) the method retains the raw measurement results of radar, and the AIS locator data higher to precision carries out spatial alternation, calculates target range respectively with utm projection, and Mercator projection calculates target azimuth, reduces the error brought in spatial alternation process;

(3) the AIS track data that the method is higher to data transfer rate carries out interpolation, decreases the error that interpolation is brought.

Four, accompanying drawing explanation

Figure of description is implementing procedure figure of the present invention.

Five, embodiment

Below in conjunction with Figure of description, the present invention is described in further detail.With reference to Figure of description, the specific embodiment of the present invention divides following step:

(1) utilize unified time service equipment to carry out time service to marine radar and AIS equipment, guarantee the time consistency of equipment;

(2) the targetpath data that export for marine radar of data 1, the AIS message that data 2 export for AIS receiving equipment, and preliminary screening is completed to AIS message, receive only the message that message authentication code is 1, receiving only and forwarding designator is the message of 0, receives only the message that accommodation degree of accuracy is 1, receives only the message that electronic position-fixing device type is the target of 1, receive only the message that electronic position-fixing device type is the target of 1, form AIS goal set A;

(3) flow process 3 is under WGS84 coordinate system, utilize the locator data cleared out in the GPS locator data of radar antenna decorating position and target AIS message, utm projection is used to calculate the distance of the relative radar of target, use Mercator projection to calculate the orientation of the relative radar of target, complete the spatial alternation of AIS target;

(4) the flow process 4 AIS goal set A that utilizes flow process 3 to provide, right there is a={mmsi _a, ρ _a, θ _a, wherein mmsi _arepresent targeted customer's identifier, ρ _arepresent target range, θ _arepresent target azimuth, if Δ ρ is distance by radar precision, Δ θ is radar bearing precision, then with [ρ _a-10 Δ ρ, ρ _a+ 10 Δ ρ] be between distance screening area, with [θ _a-10 Δ θ, θ _a+ 10 Δ θ] between screening area, orientation, the radar target simultaneously met between screening area adds radar target set B, right there is b={id _b, ρ _b, θ _b, wherein id _brepresent targeted customer's identifier, ρ _brepresent target range, θ _brepresent target azimuth, with [ρ _b-10 Δ ρ, ρ _b+ 10 Δ ρ] be between distance screening area, with [θ _b-10 Δ θ, θ _b+ 10 Δ θ] between screening area, orientation, carry out feedback screening to AIS, the AIS target simultaneously met between screening area adds the pairing goal set C of b _b;

(5) determinant 5 is right its pairing goal set C _belement number judge, if right its pairing goal set C _bhave and only have an element, then completing pairing, enter flow process 7, otherwise enter flow process 6;

(6) flow process 6 respectively with Δ ρ and Δ θ for stepping length, reduce b screening area between proceed screening, until meet the decision condition of determinant 5; If set C during certain screening _bfor sky, then b is rejected from B;

(7) flow process 7 carries out synchronous recording to the Radar Target Track data and AIS targetpath that complete pairing simultaneously;

(8) flow process 8 is resolved the Radar Target Track data received, and forms targetpath b ^(t)={ id _b, ρ _b ^(t), θ _b ^(t), t}, wherein t represents the moment of this flight path, ρ _b ^(t)represent the distance of target b in t, θ _b ^(t)represent that target b is in the orientation of t;

(9) flow process 9 is resolved the AIS targetpath data received, and forms targetpath a ^(t)={ mmsi _a, l _a ^(t), b _a ^(t), t}, wherein t represents the moment of this flight path, l _a ^(t)represent the longitude of target a in t, b _a ^(t)represent the latitude of target a in t;

(10) flow process 10 couples of AIS targetpath a ^(t)={ mmsi _a, l _a ^(t), b _a ^(t), t} carries out spatial alternation, the same step of transform method (3), forms the AIS targetpath a of polar format ^(t)={ mmsi _a, ρ ^(t), θ _a ^(t), t}, wherein ρ _a ^(t)represent the distance of target a in t, θ _a ^(t)represent that target a is in the orientation of t;

(11) flow process 11 is right flight path b ^(t)={ id _b, ρ _b ^(t), θ _b ^(t), t}, gets a ∈ C _bflight path $a^{\left(t_1\right)}=\{{\mathrm{mmsi}}_a,{{\mathrm{\&rho;}}_a}^{\left(t_1\right)},{{\mathrm{\&theta;}}_a}^{\left(t_1\right)},t_1\}$ With $a^{\left(t_2\right)}=\{{\mathrm{mmsi}}_a,{{\mathrm{\&rho;}}_a}^{\left(t_2\right)},{{\mathrm{\&theta;}}_a}^{\left(t_2\right)},t_2\}$ Wherein t ₁< t < t ₂, and t ₁and between t, t and t ₂between all without flight path, carried out the calculating of interpolation flight path by following formula:

$k=\frac{t-t_1}{t_2-t_1}$

${{\mathrm{\&rho;}}_a}^{\&prime;}={{\mathrm{\&rho;}}_a}^{\left(t_1\right)}+k({{\mathrm{\&rho;}}_a}^{\left(t_2\right)}-{{\mathrm{\&rho;}}_a}^{\left(t_1\right)})$

${{\mathrm{\&theta;}}_a}^{\&prime;}={{\mathrm{\&theta;}}_a}^{\left(t_1\right)}+k({{\mathrm{\&theta;}}_a}^{\left(t_2\right)}-{{\mathrm{\&theta;}}_a}^{\left(t_1\right)})$

The ρ calculated _a' and θ _a' be respectively a that interpolation the obtains distance and bearing in t;

(12) track points b ^(t)={ id _b, ρ _b ^(t), θ _b ^(t), t}, and a ^(t)={ mmsi _a, ρ _a', θ _a', the combination of t}, is radargrammetry value and AIS true value point pair.

Claims (5)

1. towards the measured value of marine radar calibration and AIS true value point to construction method, it is characterized in that comprising the following steps:

(1) unified time service equipment is utilized to carry out time service to marine radar and AIS equipment, guarantee the time consistency of equipment, when receiving AIS message, by message authentication code, forwarding designator, accommodation degree of accuracy and electronic position-fixing device type four indicating bits, AIS message is filtered;

(2) the AIS position report message received is resolved, and carry out space coordinate transformation according to radar antenna gps data, be converted into the targetpath data of polar form, prime area thresholding is set, this thresholding is utilized to screen radar target, retain the radar target meeting region threshold condition, and match with AIS target, if there is multiple AIS target in the region thresholding of single radar target, then reduce thresholding size gradually according to stepping method, until all radar targets and AIS target one_to_one corresponding;

(3) radar that record object is right simultaneously and AIS data, wherein radar data record object lot number, distance, orientation, time, AIS data recording user identifier, longitude, latitude, time, according to radar antenna gps data, space coordinate transformation is carried out to the AIS data of record, packet after resolving is containing customer identification number, distance, orientation, time, get the AIS flight path being close to two moment before and after the target radar flight path moment, by the method for linear interpolation, calculate the AIS flight path in radar track moment, complete the time unifying that target is right, form radargrammetry value and AIS true value point pair.

2. the measured value towards marine radar calibration according to claim 1 and AIS true value point are to construction method, and the AIS message screening wherein described in step (1), comprises following feature:

1. the message that message authentication code is 1 and 5 is received only;

2. receive only message authentication code be 1 message repeating designator be the message of 0;

3. receiving only message authentication code is that in the message of 1, accommodation degree of accuracy is the message of 1;

4. receiving only message authentication code is that in the message of 5, electronic position-fixing device type is the message of the target of 1.

3. the measured value towards marine radar calibration according to claim 1 and AIS true value point are to construction method, wherein step (2) and the space coordinate transformation described in step (3), Ship GPS locator data in the radar antenna gps data measured under using WGS84 coordinate system and AIS message, with radar antenna GPS for polar coordinates initial point, apply following technical measures:

1. range conversion adopts utm projection, calculates the distance of the relative radar antenna of target;

2. bearing change adopts Mercator projection, calculates the orientation of the relative radar antenna of target.

4. the measured value towards marine radar calibration according to claim 1 and AIS true value point are to construction method, radar wherein described in step (2) and AIS alternately screening form target pair, there is following feature: resolve the AIS message after all filtrations, solving target latitude and longitude information, and carry out coordinate transform according to radar antenna gps data, obtain AIS goal set A, right there is a={mmsi _a, ρ _a, θ _a, wherein mmsi _arepresent targeted customer's identifier, ρ _arepresent target range, θ _arepresent target azimuth, if Δ ρ is distance by radar precision, Δ θ is radar bearing precision, then with [ρ _a-10 Δ ρ, ρ _a+ 10 Δ ρ] be between distance screening area, with [θ _a-10 Δ θ, θ _a+ 10 Δ θ] between screening area, orientation, radar target is screened, the radar target simultaneously met between screening area adds radar target set B, right there is b={id _b, ρ _b, θ _b, wherein id _brepresent targeted customer's identifier, ρ _brepresent target range, θ _brepresent target azimuth, with [ρ _b-10 Δ ρ, ρ _b+ 10 Δ ρ] be between distance screening area, with [θ _b-10 Δ θ, θ _b+ 10 Δ θ] between screening area, orientation, carry out feedback screening to AIS, the AIS target simultaneously met between screening area adds the pairing goal set C of b _bif, right its pairing goal set C _bhave and only have an element, then completing target pairing; Otherwise, respectively with Δ ρ and Δ θ for stepping length, proceed screening, until pairing goal set C between the screening area reducing b _bin have and only have an element; If set C during certain screening _bfor sky, then b is rejected from B.

5. the measured value towards marine radar calibration according to claim 1 and AIS true value point are to construction method, and the time unifying that the target wherein described in step (3) is right, possesses following feature:

Right flight path b ^(t)={ id _b, ρ _b ^(t), θ _b ^(t), t}, wherein t represents the moment of this flight path, ρ _b ^(t)represent the distance of target b in t, θ _b ^(t)represent that target b is in the orientation of t, gets a ∈ C _bflight path with wherein t ₁< t < t ₂, and t ₁and between t, t and t ₂between all without flight path, carried out the calculating of interpolation flight path by following formula:

$k=\frac{t-t_1}{t_2-t_1},$

${{\mathrm{\&rho;}}_a}^{\&prime;}={{\mathrm{\&rho;}}_a}^{\left(t_1\right)}+k({{\mathrm{\&rho;}}_a}^{\left(t_2\right)}-{{\mathrm{\&rho;}}_a}^{\left(t_1\right)}),$

${{\mathrm{\&theta;}}_a}^{\&prime;}={{\mathrm{\&theta;}}_a}^{\left(t_1\right)}+k({{\mathrm{\&theta;}}_a}^{\left(t_2\right)}-{{\mathrm{\&theta;}}_a}^{\left(t_1\right)}),$

Wherein, ρ _a' and θ _a' be respectively a that interpolation the obtains distance and bearing in t, then track points b ^(t)={ id _b, ρ _b ^(t), θ _b ^(t), t} and a ^(t)={ mmsi _a, ρ _a', θ _a', the combination of t}, is radargrammetry value and AIS true value point pair.