Fig. 2.1. Np of goniometrical rns
2. 2. The error of the location determination of an aircraft
The
location of the aircraft is defined as the intersection point M,
at least two position lines. The error of measurement of the location
of the AC (the value of M,
which is located at a distance
fromM)
depends on the error of the position lines
and
determination (Fig. 2.2).
Fig. 2.2. Position lines and
Therefore, the radial error is determined by:
(2.5)
where
- an angle at which position lines intersect.
Errors
and
are random variables, so random and radial error
and its rms value:
(2.6)
where
-
the errors cross-correlation coefficient in the determination of
position lines.
Radial,
root mean square error of the AL on two conventional PL (assuming
independence of
and
definitions
and i.e.
)
(2.7)
In
practice, the mean square error
of
the i-th PL is evaluated according to the following simplified
formulas:
-
line of AC equal bearing:
;
-
lines of radiostation equal bearing:
,
where
,
,
,
- total measurement errors and the definition of NP;
- the distance between the AC and the RNP;
- the angle between the directions from the AL on two RNP.
Intersection
angle of a position lines
is a function of the relative position of the AL and PHP and distance
to them.
These
formulas show that the error of the PL determination is dependent on
the distance between the RNP and the AC. Thus, to determine the LP
and AL with a set accuracy is necessary to choose RNP by the range
and the stations must be located so that in the working area of the
system the angle
was more.
2.3. Calculation part
Let’s
estimate the accuracy of the position line (PL) determination and
draw a graph of the values of the RMS deviation of the LP from an
error of navigation parameter determination measured by RNS:
.
The error of PL determination is calculated as follows:
.km
km
km
.
km
Fig. 2.3. The graph of dependence of the rms pl values correspondingly to the error of np determination
Let’s calculate radial RMS error:
;
;
;
;
;
;
;
;
;
;
.
Fig. 2.4. A plot of the RMS of AL respectively to the angle between the directions of the AL on two RNP
CONCLUSIONS
I realized that general task of this term work is estimation of navigation task solving accuracy with using of azimuth radio navigation systems information.During the performing of this work I calculated the accuracy of the position line (PL), plotted the graph of the dependence of the mean square deviation of PL on the error of navigation parameter determination, calculated the root mean square error of the location of the aircraft determination (AL) with two position lines and plotted the graph of the values of standard deviation of the AL dependence on angle between the two directions on two radio navigation point (RNP). Radio navigation systems are aimed on navigation providing of navigation tasks solving by radio engineering methods. Determination of current value of aircraft location and the position line are important among them. Accuracy of these navigation parameters determination influences on accuracy and reliability of navigation tasks solving.
references
1. Харченко В. П. Основи практичної навігації / В.П.Харченко, В.Г.Лялько, В.Г.Мелкумян. – К. : НАУ, 2004. – 256 с.
2. Бабак В. П. Супутникова радіонавігація / B.П.Бабак, В.В.Конін, В.П. Марченко. – К. : Техніка, 2004. – 328 с.
3. Сосновский А. А. Авиационная радионавигация: спра- вочник. – М. : Транспорт, 1990. – 264с.
4. Мелкумян В. Г. Радіонавігаційні системи аеропортів. Радіомаячні системи посадки / В.Г.Мелкумян, О.О.Семенов. – К. : КМУЦА, 1998. – 108 с.
5. Мелкумян В. Г. Радіонавігаційні системи аеропортів. Кутомірні та далекомірні системи / В.Г.Мелкумян, О.О.Семенов. – К. : КМУЦА, 1999. – 108 с.
6. Радиотехнические системы / под ред. Ю. М. Казари- нова. – М. : Высш. шк., 1990. – 496 с.
7. Авиационная электросвязь. Приложение 10 к Кон-венции ICAO. – T. 3. – Монреаль : ICAO, 1995. – 334 c.
8. Воздушная навигация и аэронавигационное обеспе-чение полетов / под ред. Н. Ф. Миронова. – М. : Транспорт, 1992. – 295 с.
9. Кулик М. С. Положення про курсове проектування / М.С.Кулик, А.В.Полухін. – К. : НАУ, 2001. – 32 с.