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RelNav system presented in these works confirm that
the accuracy of this system deteriorates as the distance
between the users of the communication network
increases. We have also found that the accuracy of the
RelNav system depends on the relative position of the
users of the communication network. The [6] work
presents a method improve DME distance measuring
accuracy by using a new DME pulse shape. The
proposed pulse shape was developed by using
Genetic Algorithms and is less susceptible to
multipath effects so that the ranging error reduces by
36.0–77.3% when compared to the Gaussian and
Smoothed Concave Polygon DME pulses, depending
on noise environment. The [5] paper introduces
optimal ground station augmentation algorithms that
help to efficiently transform the current DME ground
network to enable a DME/DME positioning accuracy
of up to 0.3 nm or 92.6 m with a minimal number of
new ground DME sites. The positioning performance
and augmented ground network using the proposed
Stretched-Front-Leg (SFOL) pulse-based DME are
evaluated in two regions which have distinct terrain
conditions. The [10] Distance Measuring Equipment
(DME) is seeing renewed interest for its ability to
support future aviation navigation and surveillance
needs. It is one of the major technologies being
examined by the FAA Alternative Position Navigation
and Timing (APNT) program to support needs to
provide an alternative to GNSS in a NextGen airspace.
Facility data-base resolution and fidelity, and
precision of DME ground system location surveys are
a function of today's 0.2 nm system error limit. These
errors become noticeable when viewing flight data
that is processed to the tighter tolerances required by
APNT. Their contribution to system error will likely
require reduction [1]. The navigation subsystem in
most platforms is based on an inertial navigation
system (INS). Regardless of the INS grade, its
navigation solution drifts in time. To avoid such a
drift, the INS is fused with external sensor
measurements such as a global navigation satellite
system (GNSS). In situations when maneuvering helps
to improve state observability, virtual lever-arm
(VLA) measurements manage to gain additional
improvement in accuracy. These results are supported
by simulation and field experiments with a vehicle
mounted with a GNSS and an INS [8]. Positioning
accuracy of area navigation (RNAV) is directly related
to geometric dilution of precision (GDOP). For the
distribution of three DME beacons, this paper
establishes the GDOP algorithm model based on
DME/DME RNAV, the GDOP calculation is deduced,
and the relation between GDOP and DME ground
station distribution is given. The affection of the
geometric configuration and the baseline length of
DME stations, and of the aircraft height on GDOP
values are studied and simulated by MATLAB. In [7]
the optimal methods of DME beacon distribution for
DME/DME RNAV are proposed and all these results
will provide theoretical guidance for implementation
of DME/DME RNAV in China. Alternative
positioning navigation by DME service network is
used in many cases on-board of aircraft. This problem
is topical in case of bad accuracy of GNNS, spatially
during takeoff or landing phases of aircraft flight. In
the paper, an accurate approach of positioning by data
from DME with support of all available DMEs signals
in particular point of airspace has been discussed. An
availability area of Ukrainian DME service network
for altitude of FL320 has been evaluated. Dilution of
precision coefficient for geometrical factor estimation
in accuracy calculation of positioning by DME
network for Ukrainian airspace was used [13]. A
typical type of a DME pulse being used in practice is a
Gaussian pulse, and the achievable DME ranging
accuracy is primarily determined by the pulse shape.
[Kim, E. 2013] presents an alternative DME pulse
waveform that is able to provide much higher range
accuracy than the conventional Gaussian pulse. The
alternative pulse waveform is compliant with the
pulse shape requirements in the current DME
specifications to maintain the compatibility with
existing DME ground transponders and avionics. In
addition, the paper discuss the potential constraints in
implementing the alternative pulse in the existing
transponders and avionics. The Multi-constellation
Global Navigation Satellite System (Multi-GNSS) has
become the standard implementation of high accuracy
positioning and navigation applications. It is well
known that the noise of code and phase
measurements depend on GNSS constellation. Then,
Helmert variance component estimation (HVCE) is
usually used to adjust the contributions of different
GNSS constellations by determining their individual
variances of unit weight. However, HVCE requires a
heavy computation load [12]. [Zhao, J. et. Aall 2018]
presents a new method to improve the accuracy in the
heading angle estimate provided by low-cost
magnetometers on board of small Unmanned Aerial
Vehicles (UAVs). This task can be achieved by
estimating the systematic error produced by the
magnetic fields generated by onboard electric
equipment. The magnetic biases’ determination
problem can be formulated as a system of non-linear
equations by exploiting the acquired visual and GNSS
data [19]. The Chinese Area Positioning System
(CAPS) is a new positioning system developed by the
Chinese Academy of Sciences based on the
communication satellites in geosynchronous orbit.
The CAPS has been regarded as a pilot system to test
the new technology for the design, construction and
update of the BeiDou Navigation Satellite System
(BDS). BDS-3 type is equipped with two major
functions, namely navigation and positioning, as well
as data communication. BDS can provide seven types
of services. The results indicate a potential application
of CAPS for highly accurate positioning and speed
estimation and the availability of a new navigation
mode based on communication satellites [16]. At the
same time, many applications do not require precise
absolute Earth coordinates, but instead, inferring the
geometric configuration information of the
constituent nodes in the system by relative
positioning. The Real-Time Kinematic (RTK)
technique shows its efficiency and accuracy in
calculating the relative position. The efficiency test
shows that the proposed method can be a real-time
method, the time that calculates one epoch of
measurement data is no more than 80 ms and is less
than 10 ms for best results. The novel method can be
used as a more robust and accurate ambiguity free
tracking approach for outdoor applications [15]. To
bridge the GPS outage for multicopters is designed
proposes a novel navigation reconstruction method
for small multicopters, which combines the vehicle
dynamic model and micro-electro-mechanical system