RU2116666C1 - Complex for aboard path measurements - Google Patents

Abstract

FIELD: aviation equipment, investigation of characteristics of aircraft over all phases of flight. SUBSTANCE: proposed complex incorporates satellite and inertial navigation systems, integrating device, control and indication desk, aboard computation system for information analysis and processing, unit referencing data to common high-accuracy time and computer of actual coordinates of path of aircraft. EFFECT: increased accuracy of determination of parameters of spatial position of aircraft. 1 cl, 5 dwg

Description

 The invention relates to the field of aviation technology, in particular to equipment for conducting flight tests (LI) of aircraft (LA) and their avionics (BO) and is intended to study the characteristics of aircraft in all areas of flight.

Known optical, radio engineering, photogrammetric methods [1] for determining the flight path and spatial orientation of an aircraft, with the use of which the characteristics of an aircraft, on-board equipment are estimated from the quantitative actual values of the parameters of the movement of the aircraft and the measured systems. Optical and radio engineering methods using cinema theodolite stations (CTS), laser-rangefinder tracking systems "Opal", "Yantar", as well as radar stations, radar reflectors and radio transponders, suggest measuring range D, azimuth A, elevation, elevation , velocities for determining the coordinates of the center of mass (X, Y, Z), velocity components (V _x , V _y , V _z ) and other parameters of the aircraft. Ground-based means of external trajectory measurements (VTI), equipped with stationary means of trajectory measurements on the basis of KTS and optoelectronic laser rangefinder systems, are used to assess the takeoff and landing characteristics of aircraft and the characteristics of flight and navigation equipment (PNO).

However, the need for VTI ground stations, requiring their special placement and maintenance, limits the scope of practical use of the CCC. In addition, VTI methods have several disadvantages:
- limited visibility (≈ 50 km) and measurement of parameter values;
- Dependence on weather conditions and route selection;
- the need to have ground-based guidance radars (such as "Kama") on the track;
- the absence of stationary CTS stations and laser rangefinder systems when testing aircraft in various expected operating conditions (heat, cold, highlands) during the flight of various aerodromes for certification of the aircraft;
- the duration of the subsequent processing.

 Radio engineering systems (RTS) based on the short range navigation system (RSBN) allow you to determine the range parameters D and azimuth A at a distance of 50-350 km and based on the long range navigation system (RSDN) - geographical coordinates. However, these systems make it possible to determine a limited set of parameters and have insufficient accuracy (the Kama radar and the Vistula type phasometric system have an accuracy of several tens of meters, depending on the distance of the aircraft).

Photogrammetric methods (FGM) [1] are autonomous and are used to determine aerobatic and navigation parameters mainly when performing route flights. The method is based on obtaining photographs on board an aircraft using measuring photogrammetric equipment with special ground-based post-flight processing. The essence of determining the parameters of the spatial position of the aircraft is to determine the parameters of the trajectory from the photograph and in terms of them in the parameters of the aircraft. The main disadvantages of FGM are:
- the need to install an aerial camera;
- limited area of operation;
- dependence on weather conditions;
- the need to use a large number of cards;
- the complexity of processing.

A well-known complex of standard flight and navigation equipment for aircraft Tu-204 and IL-96 (KSPNO) [2], taken as a prototype, airborne trajectory measurements of which are made on the basis of the computer navigation system BCC-85, including:
- BTsVM;
- control panel and indications;
- system of air signals (SHS);
- strapdown inertial navigation system (SINS);
- radio navigation systems of near and distant navigation;
- satellite navigation system (SNA);
- landing systems;
- range finder and magnetic course meter;
- radio altimeter.

The complex allows you to get navigation characteristics (heading, drift angle, ground speed, inertial altitude and vertical speed, roll and pitch, angular speeds and accelerations), altitude and speed parameters and angle of attack, takeoff and landing characteristics. The near navigation equipment provides continuous positional information for correcting the calculated coordinates of the aircraft. The disadvantages of the system are:
- low accuracy of measurement of the determined parameters of the spatial position of the aircraft in the global coordinate grid in various coordinate systems when conducting the LI. Such accuracy is acceptable only for the piloting of serial aircraft, but not for evaluating the trajectory parameters in the interests of LI;
- lack of operational analysis of the flight experiment on board the aircraft by the experimental engineer in real time; duration of subsequent processing;
- large time costs when choosing test routes in the process of conducting LA aircraft. Such costs are the result of the lack of a complete aeronautical data bank containing test route parameters, complete information about beacons, aerodromes and other information to support test flights.

 The basis of the invention is the task of creating an autonomous on-board complex of trajectory measurements, which would ensure continuous receipt of the real coordinates of the aircraft in real time on all flight modes from take-off to landing to determine all the necessary characteristics of the aircraft and PNO with high accuracy, sufficient for their identification and use for certification of aircraft, regardless of geographic conditions of use, weather conditions, without the use of ground external trajectory measurements.

 In addition, the complex should provide increased productivity, reduced material costs in determining the characteristics of the aircraft in the LI process. Moreover, the complex should ensure its use on various types of aircraft, operational control over the process of determining the characteristics on board the aircraft.

 The task is achieved by the fact that the equipment of the complex of on-board trajectory measurements (CBTI), containing receivers and information sensors, including satellite navigation system (SNA), inertial navigation system (ANN), on-board digital computer system (BCVS), connected to its inputs with sensors and information receivers, control and indication panels, a unit for bringing data to a single high-precision time (BPDEVV) and a calculator for determining the actual coordinates of the aircraft trajectory and errors with system (VDKTPS), connected by its output, respectively, to the information interface device (USI) and BTsVS, while BPDEVV with its input is connected to the SNA output, and VDKTPS is connected by its inputs to the SSI, communication of receivers and sensors of the information block of the data reduction unit to a single high-precision time (BPDEVV) with BTsVS and communication VDKTPS with SNA and ANN, RSBN, RSDN and others are carried out using the information interface device (USI), made in the form of a controller, built on the principle of asynchronous exchange of information "programmable schedule", communication the unit for determining the actual coordinates and errors of the VDKTPS systems with the BCVS is made through a switch connected to the control panel, which allows to obtain the actual coordinate values with high accuracy. In specific applications on board an aircraft, the complex is supplemented by a short-range and long-range navigation system (RSBN and RSDN), a Doppler measuring system for drift and angle of drift (DISS), a landing system with a range finder and a magnetic heading meter, an instrument landing system, and a radio altimeter (RV), air signal system (SHS), database and control unit. BCVS is made in the form of autonomous calculators of navigation parameters of the SNA - ANN, parameters of near and far navigation, Cartesian coordinates, approach, altitude and speed parameters, take-off and landing characteristics, parameters of aircraft navigation, while the calculators of navigation parameters of the SNA-ANN, parameters of near and long-range navigation, approach, high-altitude and speed parameters with their first inputs are connected to the outputs of the information interface device (USI), and each of the computers with its output is connected to the bl control, the Cartesian coordinates calculator with its first input is connected to the database, and the output - with the second inputs of the calculators of the approach, altitude and speed parameters, takeoff and landing characteristics, the switch is made in the form of a logical block with fixed priorities, the first, second, third and the fourth inputs of which are connected respectively to the outputs of the VDKTPS, calculators of navigation parameters SNS-INS and the parameters of near and far navigation and the control unit, and the output of the switch is connected to the second the course of the near and far navigation parameters calculator, with the second input of the Cartesian coordinates calculator, the third inputs of the approach calculators, altitude and speed parameters, the second input of the take-off and landing characteristics calculator and the input of the airplane parameters calculator, which allows you to determine the actual values of the coordinates of the trajectory parameters in various ways : ANN-SNA, ANN-RSBN, ANN-RSDN with appropriate integrated information processing.

 This implementation of the complex allows to increase the accuracy of measurement of the determined real parameters of the spatial position of the aircraft in the global coordinate grid with an accuracy of 2-5 m (versus 150-200 m - the accuracy of KSPNO). In addition, it makes it possible to conduct an operational analysis of a flight experiment on board an aircraft by an engineer-experimenter and thereby reduce the duration of the subsequent processing of the results of the aircraft. In addition, the availability of a data bank containing test track parameters, information about beacons and other information can reduce the time spent on the preparation and execution of test flights. In general, the implementation of the KBTI makes it possible in a short time to carry out certification of modern and promising aircraft and flight and navigation equipment without the use of external trajectory measurements in all expected operating conditions of the aircraft.

 In FIG. 1 - presents a block diagram of the KBTI; figure 2 is a block diagram of a Kalman filter and figure 3,4,5 coordinate systems' - respectively, geodesic, geocentric (topocentric), orthodromic.

The on-board complex trajectory measurements (see figure 1) includes:
1 - satellite navigation system (SNA);
2 - onboard part of the SNA;
3 - inertial navigation system (ANN);
4 - radio engineering system of long-range navigation (RSDN);
5 - radio engineering system of near navigation (RSBN);
6 - landing system using a rangefinder and a magnetic course indicator (VOR / DME);
7 - instrument landing system;
8 - Doppler measuring system of speed and drift angle (DISS);
9 - radio altimeter (RV);
10 - system of air signals (SHS);
11 - block data reduction to a single high-precision time (BPDEVV);
12 - information interface device (USI);
13 - calculator for determining the actual coordinates of the aircraft trajectory and system errors (VDKTPS);
14 - switch;
15 - on-board digital computer system (BTsVS);
16 - calculator navigation parameters SNS-ANN;
17 - calculator parameters near and far navigation (RSBN-RSDN);
18 - calculator of Cartesian coordinates;
19 - database (DB);
20 - approach parameters calculator (CDW);
21 - computer altitude-speed parameters (VSP);
22 - calculator takeoff and landing characteristics (VPH);
23 - calculator parameters of aircraft;
24 - control panel;
25 - control unit;
26 - imaging device;
27 - display;
28 - on-board measurement system;
29 - documentation system;
30 - additional receivers and information sensors included in specific cases.

 The output of the onboard SNA 2 is connected to the unit for converting data to a single high-precision time 11 and through the USI 12 with the inputs of the calculator of the actual coordinates of the trajectory and errors of the VDKTPS 13 system and the parameter computer of the SNA-INS 16, and their outputs are connected to the first and second outputs of switch 14 and the unit control 25, the first input of the calculator of Cartesian coordinates 18, the first input of the calculator of take-off and landing characteristics 22, the first input of the calculator of parameters of approach 20, the input of the calculator of parameters of aircraft 23, the first input of the computer altitude-speed parameters 21 included in the BCVS-15. The input of the parameters calculator of the RSBN-RSDN 17 systems is connected via the ASI 12 to RSBN 5, RSDN 4 and the VOR / DME radio of landing system 6, respectively, and the output of the calculator 17 is connected to the control unit 25, the second input of the Cartesian coordinates calculator 18 is connected to the database 19, and its output is with the second input of the take-off and landing characteristics calculator 22 and the control unit 25, the second input of the altitude-speed parameters calculator 21, the second input of the approach calculator 20, its third input is connected via USI 12 to the instrument landing system (for example, ILS ) and VOR / DME 6 landing system, and the outputs of the approach parameters calculator 20 and take-off and flight characteristics calculator 22, the flight calculator 23, the altitude-speed parameters calculator 21 are connected respectively to the control unit 25, and the third input of the altitude-speed parameters calculator 21 via ASI 12 is connected to DISS 8, RV 9, SVS 10, the output of the unit for bringing data to a single high-precision time (BPDEVV) 11 is connected to ASI 12, and the output of control unit 25 is connected to the fourth input of switch 14, with the on-board measurement system 28, s syst My Documents 29, with an imaging device 26, whose output is connected with a display 27, which is part of the control panel 24.

 The KBTI is based on the methods of complex processing of information from precision inertial, satellite, radio engineering systems and systems of altitude and speed parameters that enter the on-board digital computer system BTsVS-15, which combines on-board computers. The interaction of the BCVS-15 with sensors and consumers is ensured through serial code channels and inter-machine communication channels.

Повышение точности формирования действительных значений пилотажно-навигационных параметров достигается использованием оптимальной КОИ с реализацией фильтра Калмана. Алгоритм КОИ с использованием избыточной информации данных систем СНС 2, РСДН 4, РСБН 5 обеспечивает оценку и компенсацию в процессе обработки погрешностей ИНС-3 Компенсация в сигналах ИНС-3 погрешностей параметров с помощью КОИ позволяет формировать высокоточные действительные значения навигационных и пилотажных параметров.BTsVS-15 solves the problems of receiving information from sensors, processing and analyzing information, generating output data, they also implement service programs to ensure operator operating modes. For this, integrated information processing (CFI) is used in the DKTPS-13 computer, the result of which is high-precision real values of the parameters of the aircraft motion. Actual parameter values are used to calculate system errors. If X is the value of one of the parameters of any evaluated characteristics of the aircraft, and X is _valid. - the actual obtained value of the corresponding parameter, the error of this system or aircraft characteristics is determined by the formula

Improving the accuracy of the formation of the actual values of the navigation and navigation parameters is achieved by using the optimal CFI with the implementation of the Kalman filter. The KOI algorithm using redundant information from these SNA 2, RSDN 4, RSBN 5 systems provides an estimate and compensation during the processing of ANN-3 errors. Compensation of INS-3 signals for parameter errors using the KOI makes it possible to generate highly accurate real values of navigation and flight parameters.

- погрешности определения вертикали и азимутального угла;

- компенсации постоянных составляющих гироскопов;

- погрешности измерения угловых скоростей ЛА бесплатформенных ИНС (для БИНС);

- дрейфы гироскопов, пропорциональные ускорениям (ИНС);

- погрешности акселерометров, пропорциональные действующим ускорениям.In the process of complex information processing in the computer 13 using the Kalman filter (19 orders), the following errors of inertial systems are evaluated:
Δ ^∧ φ, Δ ^∧ λ are the errors in determining the coordinates;
Δ ^∧ V _N , Δ ^∧ V _E - errors in determining the components of speed;

- errors in determining the vertical and azimuthal angle;

- compensation of the constant components of gyroscopes;

- errors in the measurement of the angular velocities of aircraft of the ANF strap-downs (for SINS);

- drift of gyroscopes proportional to accelerations (ANN);

- errors of accelerometers proportional to the current accelerations.

To estimate the errors of the vertical channel ANN-3, a fourth-order Kalman filter is used, which forms estimates of the following errors:
Δ ^∧ H - - error in determining the height;
Δ ^∧ V _z - is the error in determining the vertical velocity;
Δ ^∧ g _zo is the error of compensation of the acceleration of gravity;
Δ ^∧ m _zo is the error of the scale factor of the vertical accelerometer.

Работа КБТИ в режиме КОИ дает возможность получения высокоточных действительных значений навигационно-пилотажных параметров на протяжении всего полета. Так информация БИНС 3 используется как основная, в качестве избыточной информации используются данные СНС 2.The actual values of the parameters are formed by eliminating the corresponding error estimates from the ANN 3 signals:

The operation of the KBTI in the CFI mode makes it possible to obtain high-precision real values of navigation and aerobatic parameters throughout the flight. So the information of SINS 3 is used as the main, as the redundant information is used the data of SNA 2.

The SNA 2 error model is represented as a discrete random process such as white noise with a known dispersion. The Kalman filtering algorithm provides the best linear estimates of the state vector of the system X _k at time t _k , when X _k is determined from the equation of state:
X _{k + 1} = Φ _{k + 1, k} X _k + g _k (3)
and the measurement vector Z _k is represented as
Z _k = H _x X _k + rk (4)
Here g _k , r _k are independent noises with zero mean values and a covariance matrix;
COV [g _k ] = Q _k ; COV [r _k ] = R _k (5)
Ф _{к + 1, к} - fundamental matrix, H _к - measurement matrix.

где
Х_к(к-1), Х_к/к - априорная и апостериорная оценки вектора состояния Х на к-м шаге;
Р_к/к-1, Р_к/к - априорная и апостериорная ковариационные матрицы на к-м шаге.The algorithm consists of two stages and has the following form:
- an estimate of the state vector between measurements is given by the equation
X _{k / k-1} = F _{k, k-1} • X _{k-1 / k-1} (6)
- assessment when measuring

Where
Х _{к (к-1)} , Х _{к / к} - a priori and a posteriori estimates of the state vector X at the kth step;
P _{k / k-1} , P _{k / k} - a priori and posterior covariance matrices at the kth step.

To _to - weight matrix, figure 2.

 To overcome the numerical difficulties associated with the possible loss of symmetry and positive definiteness of the covariance matrix and to increase the accuracy of the estimates, we use the filtering method with a quadratic representation of the covariance matrix — the square root method from the matrix based on the representation of the covariance matrix P in the form P = SS, where S is upper or lower triangular square matrix [3].

 To ensure this processing in order to exclude the influence of transients in the Kalman filter on the accuracy of estimates of ANN-3 errors at the initial flight section, algorithms for smoothing estimates are used to obtain equal-precision ANN-3 errors from take-off to aircraft landing.

H_д = h_снс + V_н(t-t_снс).The calculator 16 determines the actual values of the trajectory parameters according to the information of the SNA-2 and ANN-3. The latitude φ _D , longitude λ _D and height H _{d are} determined using the following relationships:

H _d = h _ssn + V _n (tt _ssn ).

where φ _sss , λ _sss , h _sss are the coordinates of the aircraft issued by SNA-2 at time t _sss ,
V _N , V _E , V _n - components of the velocity vector, taken from the output parameters of ANN-3;
r _N , r _E are the radii of curvature of the earth's ellipsoid;
t is the current time. The values of the remaining output parameters are assumed to be equal to the corresponding values of the parameters received from SNA-2.

The calculator 18 determine the Cartesian coordinates and speed allows you to convert:
- geodetic coordinates B - latitude, L - longitude, H - height for the aircraft in Cartesian coordinates X, Y, Z;
- northern V _N eastern V _E and vertical V _y components of the aircraft speed in the velocity projection in the Cartesian coordinate system V _x , V _y , V _z .

где
ξ - разность между астрономической и геодезической широтой и вычисляется по формуле:

a - большая полуось эллипсоида Земли; e - эксцентриситет эллипса.The coordinates of the point M, ascended above the ellipsoid to a height H = MM, will be equal to:

Where
ξ is the difference between the astronomical and geodetic latitude and is calculated by the formula:

a - semimajor axis of the Earth's ellipsoid; e is the eccentricity of the ellipse.

Used coordinate systems:
- right rectangular geocentric coordinate system Oξζη, FIG. 4.

- the Cartesian coordinate system OXYZ, the origin at the point B _o L _o H _o , the OY axis coincides with the vertical direction, A _o is the angle between the OX axis and the north direction.

местоположения ЛА относительно фиксированной точки аэродрома (аэродром посадки) и вектора скорости V для ЛА в геоцентрической системе координат определяются:

где
ξ,ζ,η - координаты ЛА в геоцентрической системе координат.Vector projection

the location of the aircraft relative to the fixed point of the aerodrome (landing aerodrome) and the velocity vector V for the aircraft in the geocentric coordinate system are determined:

Where
ξ, ζ, η are the coordinates of the aircraft in the geocentric coordinate system.

a - большая полуось эллипсоида;
ε - эксцентриситет эллипсоида.

a is the semimajor axis of the ellipsoid;
ε is the eccentricity of the ellipsoid.

Проекции векторов

в декартовой системе координат OXYZ определяются

- матрица направляющих косинусов осей одного трехгранника относительно другого.Speed components are determined by:

Vector projections

in the Cartesian coordinate system OXYZ are determined

- the matrix of the directing cosines of the axes of one trihedron relative to another.

Проекции составляющих геоцентрических координат относительно начала топоцентрической системы:

Прямоугольные геоцентрические координаты ЛА и начала прямоугольной топоцентрической системы координат

В вычислителе параметров 17 ближней и дальней навигации РСБН-РСДН координаты φ_Д,λ_Д , H_д пересчитываются в декартовой системе координат X, Y, Z по формулам (9) в геодезической системе по формулам:

где (X₁, Y₁, Z₁) и (X₂, Y₂, Z₂) - прямоугольные координаты точек 1 (ВПП) и 2(РСБН); работа РСБН в пределах прямой видимости

В вычислителе 22 взлетно-посадочных характеристик ЛА используется правая декартовая земная система координат, начало которой связано с ближним торцом ВПП фиг. 4. Ось OX_g направлена вдоль оси ВПП в направление взлета или посадки, ось OY_g вертикальна плоскости местной горизонтали, а ось OZ_g образует правую тройку.a ₁₁ = -sinB _o cosL _o cosA _o -sinL _o sinA _o
a ₁₂ = -sinB _o sinL _o cosA _o + cosL _o sinA _o
a ₁₃ = cosB _o cosA _o ; a ₂₁ = cosB _o cosL _o ; (16) a ₂₂ = cosB _o sinL _o
a ₂₃ = sinB _o ; a ₃₁ = sinB _o cosL _o sinA _o -sinL _o cosA _o
a ₃₃ = sinB _o sinL _o sinA _o + cosL _o cosA _o ; a ₃₅ = -cosB _o sinA _o
The Cartesian coordinates calculator is connected by the BD-19, where the data (coordinates) of the flying around aerodromes are located. The rectangular topocentric coordinates of the aircraft are found:

Projections of the components of the geocentric coordinates relative to the beginning of the topocentric system:

Rectangular geocentric coordinates of the aircraft and the beginning of a rectangular topocentric coordinate system

In the calculator of parameters 17 near and far navigation RSBN-RSDN coordinates φ _D , λ _D , H _{d are} converted in the Cartesian coordinate system X, Y, Z according to formulas (9) in the geodetic system according to the formulas:

where (X ₁ , Y ₁ , Z ₁ ) and (X ₂ , Y ₂ , Z ₂ ) are the rectangular coordinates of points 1 (runway) and 2 (RSBN); RSBN operation within line of sight

In the aircraft 22 take-off and landing characteristics calculator, the right Cartesian earth coordinate system is used, the origin of which is connected with the near end of the runway of FIG. 4. The axis OX _{g is} directed along the runway axis in the direction of take-off or landing, the axis OY _{g is} vertical to the local horizontal plane, and the axis OZ _g forms the right triple.

Путевая скорость определяется как

Угол наклона траектории вычисляется по формуле

Путевой угол вычисляется по формуле:

Траекторный угол скольжения вычисляется:
β_тр= ψ_п-ψ_впп+ψ (26)
Определяется дистанция взлета
L_взл = X_т - X_о, (27)
где X_т - координата точки окончания взлета; X_т - соответствует моменту прохождения высоты H = 10,7м;
X_о - координата точки старта, X_o - соответствует моменту, когда продольное ускорение ЛА принимает значение n_x ≥ 0,05 e.n. Дистанция прерванного взлета определяется:
L_{прер.взл} = X_ост - X_о, (28)
где X_ост - координата точки окончания взлета;
X_о - координата точки старта;
Дистанция посадки определяется:
L_пос = X - X_о, (29)
где X - координата ЛА в момент прохождения им высоты H=15 м.The ground speed of the aircraft is determined according to the formula:

Ground speed is defined as

The angle of inclination of the trajectory is calculated by the formula

The direction angle is calculated by the formula:

The trajectory glide angle is calculated:
β _mp = ψ _n -ψ _runway + ψ (26)
Takeoff distance determined
L _vzl = X _t - X _o , (27)
where X _t - coordinate of the end point of take-off; X _t - corresponds to the moment of passage of the height H = 10.7 m;
X _o - coordinate of the start point, X _o - corresponds to the moment when the longitudinal acceleration of the aircraft takes on the value n _x ≥ 0.05 en The distance of the interrupted take-off is determined by:
L _interruption = X _ost - X _o , (28)
where X _ost - the coordinate of the end point of take-off;
X _o - coordinate of the starting point;
The landing distance is determined by:
L _pos = X - X _o , (29)
where X is the coordinate of the aircraft at the moment of passing the height H = 15 m

X _about - the coordinate of the aircraft at the time of its complete stop, when h _x changes sign h _x = ± 0,05e.n.

The deviation of the aircraft from the glide path is determined
ΔH _hl = Y _D - (X _D -X _gN ) tgθ _hl (30)
where X _um - the longitudinal coordinate of the glide path beacon;
θ _hl - the angle of inclination of the glide path.

The drawdown (loss of altitude) in the process of aircraft withdrawal from the descent mode when leaving for the second circle is calculated
ΔH _yx = HH _yx , (31)
Where
H is the height of the decision to leave for the second round;
H _yx is the minimum height above the runway surface during the approach to the second circle, H _yx = min (Y _d ).

Surfaces of obstacle constraints are described by the relations:
N _ogr.vzl = To _century X _in
N _og.pos = To _item X _on
Z _og = K _z. X _side. , (32)
where K _p , X _by ; K _in , X _in ; K _z , Z _pro - respectively, the slope gradients and the coordinates of the intersection of the obstacle restriction surface with the earth's surface during landing, take-off and lateral surface of the restriction (1 / p, m).

В вычислителе 21 высотно-скоростных параметров реализован скоростной метод определения аэродинамических поправок (давления) по скорости ЛА V_a, на основе информации от ИНС о путевой скорости, проекциях путевой скорости на координатные оси X, Z, путевом угле и о текущих значений воздушной и приборной скорости от СВС-10. Кроме того, дополнительно необходимы значения барометрической высоты H_бар, температуры T наружного воздуха, угол атаки (местный или истинный), углы крена и тангажа.The height of the span above the surface of the obstacle restrictions is determined by:

The calculator 21 altitude-speed parameters implements the high-speed method for determining aerodynamic corrections (pressure) from the aircraft speed V _a , based on information from the ANN on the ground speed, the projection of the ground speed on the X, Z coordinate axes, the track angle and the current air and instrument speeds from SVS-10. In addition, the values of barometric height H _bar , temperature T of outdoor air, angle of attack (local or true), roll and pitch angles are additionally required.

;
δV_сж - поправка скорости на сжимаемость;
P_н, T_н - давление и температура воздушной среды.The error is determined by the formula
δV _A = V _ave -Δ • V + δV _{compression channel} (34)
where V _CR - the instrument speed, the average value on the mode (km / h),
Δ is the relative density of air

;
δV _SJ - rate correction for compressibility;
P _n , T _n - pressure and air temperature.

где Δψ - неточность выдерживания курса на встречных проходах,
V_x1, V_x2, V_z1, V_z2 - проекции путевой скорости на координатные оси.True airspeed V is determined

where Δψ is the inaccuracy of maintaining the course on the oncoming passages,
V _x1 , V _x2 , V _z1 , V _z2 - projection of ground speed on the coordinate axis.

После выполнения разворота и второго прохода средние значения вычисляются в соответствии с указанной формулой (36). По окончании режима получается расчет аэродинамической поправки по скорости V_a для соответствующего значения скорости, пересчет полученной поправки в остальные значения (H_a, M_a) и выдача результатов для накопления.On a steady horizontal flight, the average values of the ground speed V _put , course angle, instrument speed V _pr , etc. are calculated. as:

After the turn and the second pass, the average values are calculated in accordance with the specified formula (36). At the end of the regime, the aerodynamic correction is obtained from the speed V _a for the corresponding speed value, the correction is recalculated into other values (H _a , M _a ) and the results are obtained for accumulation.

В вычислителе параметров 23 самолетовождения (определяются погрешности частноортодромических координат в горизонтальной (ΔZ) и продольной (ΔS) плоскостях, которые необходимы для оценки режимов, а также действительные значения пройденного ЛА расстояния S_пр.д - расстояние, пройденное ЛА между коррекциями S_ΔΣ . Эти параметры необходимы для оценки самолетовождения в горизонтальной плоскости на маршруте и при маневрировании самолета в 100 км-зоне аэродрома. Для этого в вычислителе 23 пересчитываются действительные геодезические координаты φ_Д,λ_Д (B, L) в частноортодромические Z_д, S_д.Algorithms for determining deviations from the course and glide path zones Δε _k , Δε _{g of} course deviations Δψ at the moments from the capture of the course and glide zones to the touch of the runway or the path deviations ΔΗ, ΔΖ

In the calculator of the parameters of 23 aircraft navigation (the errors of the partial orthodromic coordinates are determined in the horizontal (ΔZ) and longitudinal (ΔS) planes, which are necessary for evaluating the modes, as well as the actual values of the distance traveled by the aircraft, S _a.s. - the distance traveled by the aircraft between the corrections S _ΔΣ . These the parameters are necessary for evaluating horizontal navigation on the route and for maneuvering the aircraft in the 100 km zone of the aerodrome.For this, the actual geodetic coordinates φ _{D are} recalculated in calculator 23, λ _D (B, L) to private orthodromic Z _d , S _d .

 The errors of the current point M in the orthodromic coordinate system are defined by the orthodromic latitude B, the orthodromic longitude L and the distance R to the center of the earth.

R=R_ср=a (38)
X₀=X_дcosL₀+Y_дsinL₀
Y₀=-X_дcosB₀sinL₀+Y_д cosB₀ cosL₀+Z_дsinB₀ (39)
Z₀=X_дsinB₀sinL₀-Y_д sinB₀cosL₀+Z_дcosB₀

Погрешности в определении координат в вычислителе самолетовождения определяются как

где Z_{тек нв} и S_{тек нв} - текущие параметры, поступающие из навигационного вычислителя
Действительное значение расстояния, пройденного ЛА между коррекциями определяется по формуле:

где
S_{д нач} - длина ортодромии, соответствующая начальному значению участка;
S_дi - сумма длин ортодромий, заключенных между начальной и конечной для данного участка расчета Sд.Calculations of B, L, R are made according to the formulas:

R = R _cf = a (38)
X ₀ = X _d cosL ₀ + Y _d sinL ₀
Y ₀ = -X _d cosB ₀ sinL ₀ + Y _d cosB ₀ cosL ₀ + Z _d sinB ₀ (39)
Z ₀ = X _d sinB ₀ sinL ₀ -Y _d sinB ₀ cosL ₀ + Z _d cosB ₀

Errors in the determination of coordinates in the airplane calculator are defined as

where Z _{tech nv} and S _{tech nv} are the current parameters coming from the navigation computer
The actual value of the distance traveled by the aircraft between the corrections is determined by the formula:

Where
S _{d beg} - the length of the orthodromy corresponding to the initial value of the site;
S _di - the sum of the lengths of the orthodromes, concluded between the initial and final for this section of the calculation Sd.

S _{d con} - the length of the orthodromy corresponding to the final section.

SNA (1-2) includes 22 navigation satellites that are located in their orbits in such a way that at any time at least 4 satellites are observed at any point on the Earth; receiving a signal from an n-navigation satellite allows you to determine the necessary values on the aircraft:
Due to the fact that the satellite communicates the constant parameters of its orbit through the communication channel, its coordinates φ, λ H and speed V _xn , V _yn , V _zn are calculated on the aircraft and the range D _n (t) between the aircraft and the satellite and Dn is determined by the received signal (t) its changes.

When measuring the navigation parameters D _n (t) and D _n (t), a high-frequency signal is transmitted from the satellite, modulated in phase using a time function, the shape of which is known in advance both on the satellite and on the aircraft.

Usually this is a sequence of rectangular pulses of positive and negative polarity - a pseudo-noise sequence: the law of alternating positive and negative pulses is known on the satellite and at the receiving point - the received high-frequency signal is demodulated and after that the pseudo-noise sequence and pseudo-noise signal of the same shape generated in the receiving device are attached to total time using airplane frequency standards. The time shift between this signal and the signal from the satellite determines the transit time of radio waves from the satellite to the aircraft and the distance D _n (t) between them. The speed V _n (t) = D _n (t) of the range change is determined either by the rate of "tracking" of the pseudo-noise signal generated on board the received signal, or by the Doppler shift of the received radio signal.

Elements of the satellite’s orbit, which with high accuracy can be considered constant for 1-2 hours, are transmitted from the satellite with an interval to all consumers. The Cartesian coordinates X _sn , Y _sn , Z _{sn of the} satellite are calculated from the orbit and onboard time for any previously set (current) time, and the aircraft’s location is determined from the distances to three satellites at known points in space. From the values of the rate of change of range to three satellites, the vector V of the aircraft’s ground speed is calculated.

 Satellite signals are emitted in two frequency ranges for consumers with authorized access (increased measurement accuracy) and accessible to any consumer. To increase the accuracy characteristics, a differential method for determining the location coordinates is used, the essence of which is to identify and take into account, as corrections, the highly correlated components of the errors in navigation parameters using ground control points. At the NKP using the consumer equipment, the coordinates are determined and compared with the data of the geodetic reference. Then, the corresponding SNA for a given region is calculated, which allows them, by introducing amendments, to increase the accuracy of the navigation definition.

 ANNS-3 platform or strapdown type [2] provides autonomous calculation of the coordinates of the location of the aircraft and flight altitude by integrating accelerations measured by accelerometers. Setting the inertial system for the schuller period (84.4 min) ensures the construction of a vertical unperturbed acceleration in flight.

 A strapdown inertial system (SINS) provides for the determination and delivery of the following parameters to the consumer of an aircraft: geographical coordinates, ground speed and components of ground speed, angular positions of the aircraft, angular acceleration speeds, vertical speed and altitude.

 BINS-3, in comparison with platform ones, provides determination of a larger number of aircraft motion parameters and is built on the basis of laser gyroscopes, providing them with higher reliability and low availability.

RSBN measures the rectilinear distances D _r and azimuth A _r from the beacon on the aircraft. For this, an aircraft airborne transmitter emits pulses that are re-emitted by a ground beacon. The time interval T _s between the measured and received pulses determines the distance D _r = 0,5T _s C, where C is the propagation velocity of radio waves. To measure the angle A _{r, the} beacon antenna has a narrow radiation pattern, which can be imagined as a half-plane passing through the local vertical for the lighthouse and rotating around this vertical at a constant and known speed. At the moment the half-plane passes through the meridian plane (in its Northern direction) another omnidirectional antenna emits a signal that is received on the aircraft. The second signal is received on board when the aircraft enters the plane of the radiation pattern. From the time interval Ta between two pulses, one can judge the azimuth A _r - Ta.

RSDN-4 provides the measurement of two differences D ₁₂ and D ₁₃ between the ranges D ₁ , D ₂ , D ₃ .

где l₁₂ и l₁₃ - известные расстояния между ведущей и ведомыми 2,3 радиостанциями.D ₁₂ = D ₂ -D ₁ ; D ₁₃ = D ₃ -D ₁ , where D ₁ , D ₂ , D ₃ are the shortest distances between the aircraft and the leading 1 and the slave 2,3 radio stations. The physical information carrier in this system is the time delays T ₁₂ and T _{13 of the} arrival of pulses to the aircraft from the master and slave radio stations. The leading radio station (emits a pulse received on the aircraft and on each of the slave radio stations, which, after the code delay time ((τ ₂ , τ ₃ )), in turn emit pulses reaching the aircraft, with T ₁₂ and T ₁₃ being

where l ₁₂ and l ₁₃ are the known distances between the master and slave 2,3 radio stations.

The measured values of T ₁₂ and T ₁₃ are calculated the difference D ₁₂ and D ₁₃ .

РСДН строится на основе фазового (или импульсно-фазового) метода измерения времени запаздывания. Описание нижеприведенных систем дается в источниках: Система VOR/DME-16 [5] , система посадки ILS-7 [5], ДИСС-8[4], РВ-9[4], СВС-10[4].

RSDN is based on the phase (or pulse-phase) method of measuring the delay time. The description of the following systems is given in the sources: System VOR / DME-16 [5], landing system ILS-7 [5], DISS-8 [4], PB-9 [4], SVS-10 [4].

Information Interface Device (ASI) 12 — synchronous controller device — device control system for sensors. The asynchronous principle of information exchange ensures the independence of the systems of the complex, USI-12, memory and arithmetic devices of computers. KBTI systems are characterized by the following stages of work. The full cycle of T _PC work consists of the preparation of a quantum of information, reducible to the transformation of the encoding of the presentation of information - T _sub. ; the transmission of the prepared quantum between the data registers of the sensor systems and the corresponding input registers USI - T _before. ; expectations during which the actions in the sensor systems are suspended until the signals allowed from the processors of the computers are received. The transition from stage to stage is carried out under the influence of control signals in a certain sequence, the repeating elements of which form the full cycle of the sensor systems and USI-12 - T _PC . For asynchronous sensor systems, the cycle has a variable duration determined by the terms
T _PC = T _sub. + T _before. + T _expect. ,
moreover, the inconstancy of its duration is explained by the inconstancy of T _sub. and T _expect. , since the time of transmission and reception, taking into account the delay on the communication lines, must coincide, then to ensure this condition, the SDI 12 provides for buffering - the introduction of a buffer memory device that allows you to delay the moment of receiving a quantum of information relative to the time it was issued.

 USI 12 converts sequential codes into BTsVS 15 codes and vice versa - BTsVS 15 codes into serial codes and one-time commands. USI 12 is connected with the tested on-board equipment for the electrical matching of the controlled signals and digitalization of the signals of the sensors of the on-board systems. USI-12 includes an exchange module for interfacing with an information transmission line and executes commands addressed to it, and controls the operation of all unit modules. The serial code module receives and issues the serial code. The module of analog and one-time signals receives and issues analog and one-time signals.

 Information from SNA 2, ANN 3 and others is inputted using an adapter from the ASI 12. The interface module (subsequent) provides full input of information flows in accordance with GOST 18977-79 (ARiN 429). The set timer makes it possible to temporarily bind each input word, which allows you to determine the cyclogram for the issuance of code information by the system separately and the entire complex as a whole.

 Information on-board systems 2-10 through the adapter is entered into the input buffer of each calculator. The size of the buffer is selected in such a way as to accommodate a limited (not less than a second) implementation of the input information. In the input buffer, each word is contained in its entirety in conjunction with information about the time the word arrived at the input of the block. The selection of processed parameters from the input buffer and their primary processing is carried out in accordance with the selected composition of these types of parameters. Then the corresponding procedure is connected in the processing program, i.e. the first parameter in the block is a frame mark of the corresponding parameter block [6].

 USI 12 provides reception and issuance of one-time commands, reception, conversion, storage and issuance to the computer processor of information coming from complex systems in the form of serial codes (PC) with various frequencies (up to 100 Hz), reception from the computer processor, storage, conversion and issuance in a complex of information systems in the form of a PC. Information is transmitted using separate bifilar communication lines on a one-to-one basis or using common bifilar communication lines on a one-to-all basis. In this case, the number of receivers connected to one transmitter input is determined by the required sequence diagram. Signal levels, word structure and temporal characteristics of a bipolar three-level PC according to the specified GOST. The method of tuning the input channels of the PC to the specified frequency of PC reception firmware.

 The transmission of word and message signals in the general communication line of the highway is carried out at strictly defined time intervals according to the schedule - the exchange mode is “programmed schedule”, which can be changed using commands issued by the programs of systems having the corresponding priority levels. The beginning of the interval is calculated programmatically from the sync word of systems having certain priorities for its issuance. Sinhroslova are standard words with specific addresses. The informational part of the word is used for additional information. Synchroswords are issued by the systems once per cycle for a duration of 0.5 s.

 The main information element is a digital word containing 32 bits. To transmit discrete commands and messages, a code word (K) is used. All types of words are identified at the address of the word. The word address is placed in digits 1-8.

 The system of single time (SEV) KBTI is intended to form a scale of Moscow (Greenwich) time and provide the current time code with the output information. In the KBTI information frame, time is present as a parameter. The unit for bringing data to a single high-precision time (BPDBVV 11) includes a time storage module-timer and a module for receiving reference time signals. In KBTI, the source of reference signals is the SNA 2 receiver for receiving GLONASS or GPS signals on board an aircraft.

 At the same time, the time storage module provides pairing with the SNA 2 by the synchronization signals “1c” of the time code. The signal "1c" in the SNA 2 is a positive pulse, which is transmitted through a special output. The time code contains information about the current time of day, date and time correction of the pulse "1" and is transmitted in the output information frame to the structure of GOST 18977-79.

 The information entered through USI 12 has a time reference at the level of each input word - a time parameter based on a timer. The timer captures the moments of receiving information. The initial value of the time parameter is zero. In addition, information (parameter) about the system time of the computing system at the time of processing the SNA 2 information, a parameter of the astronomical time of issuing a packet of SNA 2 information, a time delay parameter for issuing a packet of relative coordinate determination time is needed.

 The accuracy of the time reference is determined by the resolution of the timer located in the data input adapter of the SSI 12.

 The binding to a single time of the actual values of the parameters measured in the complex and similar parameters obtained from the test equipment is carried out BPDEVV 11.

где
j = 1,...n, n - количество параметров во входном потоке;
b_i(j) - текущее значение j-го параметра;
b_p(j) - предыдущее значение j-го параметра;
t - текущее время, соответствующее j-му параметру;
t_p - значение времени в предыдущий момент;
t - значение времени, в которое должно произойти совмещение информации;
b_i(t) -значение переменной на момент расчета.In block 11 coordination and synchronization, the combination of time parameters in the input stream is a linear extrapolation:

Where
j = 1, ... n, n is the number of parameters in the input stream;
b _i (j) is the current value of the j-th parameter;
b _p (j) is the previous value of the j-th parameter;
t is the current time corresponding to the j-th parameter;
t _p - time value at the previous moment;
t is the value of the time at which the combination of information should occur;
b _i (t) is the value of the variable at the time of calculation.

 The switch 14 is made in the form of a logical block with fixed priorities, the first, second, third and fourth, the inputs of which are connected respectively to the inputs of the VDKTPS, calculators of navigation parameters SNS-INS 16, parameters of near and far navigation 17 and the control unit 25, and the output of the switch 14 connected to the second input of the calculator 17 parameters of near and far navigation, with the second input of the calculator of Cartesian coordinates 18, the third inputs of the calculators of approach 20, high-altitude-speed parameters 21, the second input you numerator 22 take-off and landing characteristics and the input of the calculator 23 parameters of aircraft navigation.

 In the logical block 14, the program operator determines the transfer of control according to one of the logical labels defined by the switch list of the operator. The switch 14 performs external control produced by the human operator, implemented using the keyboard.

 Database 19 is a centralized collection of data in a computer system supported by a control system. The real-time computing system, database 19 is a collection of relationships — records of tuples or rows. The relation string describes the properties of a particular object in the subject area and can be considered as a formal record of knowledge about the properties of this object. Lines of one relationship describe homogeneous objects in the subject area. Relation - a table whose lines are records describing specific objects of the subject area (airfields, their coordinates, test equipment). Data management - the functions of the control program that provide both access to data sets and the implementation of agreements adopted in the system, regulate the use of input / output devices, and search and modify data.

 The control panel 24 provides operational and pre-flight modes of preparation, inspection and operation of KBTI. The equipment included in it is described below.

 To ensure the work of the engineer-experimenter in the LI process, the operator interactively operates in a complex, the display modes and indication of the analysis results are selected by the experimenter at the pace of the experiment. To this end, information on the display 27 comes from the control unit 25 through the imager 26. The graphical (coordinate) display 27 allows you to observe on the screen the process of execution of the modes, to control the values of individual parameters of the PNO and aircraft systems. Display 27 allows you to display the parameters as a function of two variables ("parameter by parameter"), which makes it possible to adjust the flight program.

 On the display 27 are plotted according to the errors accumulated during the flight. The actual values of the parameters are used to display on the display 27 the flight path of the aircraft and its deviations from a given path line in all flight modes of the aircraft. The digital alphanumeric display 27 is made on the basis of a cathode ray tube (CRT) or a liquid crystal screen. With their help, the physical quantities of the recorded and calculated parameters are displayed on the display in digital, mnemonic, graphic form. The display provides the on-line editing of graphic windows, the quick loading of information display formats, the combination of graphs corresponding to different implementation times.

 Shaper 26 image is intended for interaction on a multiplex image transmission line and the formation of image signals. It consists of an exchange module, a graphic controller for a display memory module. The signals on the multiplex bus transfer information to the exchange module, which provides its reception and conversion into an information array that evaluates the image received by the graphics controller. The graphic controller, by the commands of the exchange module, generates digital signals, backlight signals and other control signals. The graphics controller is designed to receive information from the exchange module, decrypt its digital image control signals.

Documentation system 29, built on the basis of mini-computers, allows you to perform the following operations:
- layout of documents in the form of text tables;
- online loading of document formats in real time;
- operational change of source data for the formation of documents;
- debugging the layout of the document on the display;
- plotting on a printer or plotter graphs with the ability to overlay parameters from different modes;
- output to the printer a graphical copy of the display;
- selective copying - forming a database - copies containing accompanying information (comments, aircraft name, list of parameter names, experiment date (day, month, year), N implementation and N experiment).

 To work in the "graphical documentation" mode, the operator prepares formats for presenting output documents in the form of a text file in advance. Format files are in the file directory. The user prepares formats for presenting output documents in the form of a separate text file with a name in the same directory.

The control unit 25, made on the basis of the controller,
- carries out the interaction of subsystems;
- selects a boot configuration option for various tasks of recording and analyzing information;
- distributes information flows through the channels of input adapters, database directories and service files;
- loads the screen for displaying information on the display.

 The on-board measurement system 28 is designed to accumulate information about the results of express information processing at the pace of the experiment for the purpose of subsequent (post-flight) express analysis. This takes into account a wide range of tasks and various requirements depending on the stages of the flight to the composition of the measured parameters, their accuracy and polling frequencies. The system is based on a mini-computer and magnetic recording equipment for recording digital streams from channels. The equipment contains blocks and devices for receiving, converting information, sampling and thinning parameters. The blocks include measuring transducers, digital-to-analog and analog-to-digital converters, multichannel input / output devices for digital information, a control and interface board, as well as a magnetic recorder with magnetic tape media or a magnetic disk drive (“Winchester”).

 The KBTI assumes the presence on board of a human operator who analyzes information during the tests, monitors the performance of flight modes and the operation of the systems under study, sets test control actions. The operator selects the mode of operation of the complex, enters the accompanying information into the memory blocks, edits utility programs, controls the operation of the complex as a whole.

 An operator sitting at the KBTI control panel, having familiarized himself with the flight sheet, determines the purpose of the LI. It coordinates the inclusion of the CBTI in accordance with the timing of the modes. Then he starts the display and the complex from the keyboard with the keyboard, checks the passage of the input data. Using the "menu" goes to the table of parameters and scale coefficients of the graphs on the screen.

 The analysis mode is selected from the “menu” from the list of databases located in the directory, using the cursor keys, the required one is selected, after which the formats for displaying information on the display will be loaded. Remote control is controlled by pressing keys and their combinations.

Literature
1. Testing methodology for flight and navigation systems of aircraft and helicopters. / Ed. Novodvorsky E.P. and Harina E.G. M .: Engineering, 1984, p. 80.

 2. Anikin A.M., Belkin A.M., Litin A.V. Ed. Mironova N.F. Air navigation and air navigation support for flights. M .: Transport, 1992, p. 155.

 3. Filtering and stochastic control in dynamic systems. / Ed. Leondes K.T. M .: Mir, 1980.

 4. Pomykaev I.N., Seleznev V.P., Dmitrochenko L.A. Navigation devices and systems. M .: Engineering, 1983, p. 44, 79, 381.

 5. Belogorodsky S.L. Landing management automation. M .: Transport, 1972, p. 51, 65.

 6. Larionov A.M., Gornets N.N. Peripherals in computing systems. M .: Higher school, 1991, p. 19.

Claims (2)

 1. A complex of on-board trajectory measurements, comprising a satellite navigation system, an inertial navigation system, an on-board computer system for analyzing and processing information, an interface device and a control and display panel, the satellite and inertial navigation systems via an interface device connected to the on-board computer system for analyzing and processing information , to the control and display panel, characterized in that a data conversion unit for a single high-precision time is entered into it and calculates The actual coordinates of the aircraft’s trajectory, the input of the last of which is connected through the interface to the output of the data conversion unit to a single high-precision time, which is connected to the output of the satellite navigation system, and the output of the computer’s actual coordinates of the aircraft’s trajectory is connected to the control and display panel and to the input on-board computer system for analysis and information processing.  2. The complex of on-board trajectory measurements according to claim 1, characterized in that it is additionally equipped with a radio system of near and far navigation, a Doppler measuring system of speed and drift angle, a landing system with a range finder and a magnetic course meter, an instrument landing system, a radio altimeter, an airborne system signals and a database, and the on-board computer system for analyzing and processing information consists of autonomous calculators of navigation parameters of satellite and inertial navigation systems , approach parameters, near and far navigation parameters, Cartesian coordinates, altitude and speed parameters, take-off and landing characteristics and airplane navigation parameters, while stand-alone calculators of navigation parameters of satellite and inertial navigation systems, short and long range navigation parameters, approach, high-speed parameters with their first inputs are connected to the device for information interfacing, and the outputs of calculators of navigation parameters of satellite and inertial navigation systems, near and far navigation parameters, approach, Cartesian coordinates, altitude and speed parameters, take-off and landing characteristics and aircraft navigation parameters are connected to the control and display panel, the autonomous Cartesian coordinates calculator is connected to the database with its first input, and the output - with the second inputs of the stand-alone calculators of the approach, altitude and speed parameters, the first input of the take-off and landing characteristics calculator, and the connection of the output of the actual coordinates calculator along the path of the aircraft with the input of the on-board computer system for analyzing and processing information and the control and display panel is made in the form of a switch, the first input of which is connected to the output of the calculator of the actual coordinates of the path of the aircraft, the second and third inputs of the switch are connected respectively to the outputs of the autonomous calculators of navigation parameters of the satellite and inertial navigation systems, radio systems of near and far navigation, fourth switch input of Tell connected to the control and display panel, and an output switch coupled to a second input of auxiliary Cartesian coordinate calculator, a third input parameter calculators approach for landing, the altitude-velocity parameters, the second input of the calculator landing characteristics calculator piloting input parameters.

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