Investigation of most ideal GNSS framework (GPS, GLONASS and GA…

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open-cut mines. The advantages of the normal additional

satellites and their signs are expanded accessibility, exactness,

congruity, and dependability.

General Terms

Analysis of the DOP Values and Availability of combined

GPS/GLONASS/GALILEO Navigation system in Bangladesh

and some specific city of the country.

Keywords

GNSS; DOP; Performance analysis.

1. INTRODUCTION

The necessity of precise GNSS system is undeniable in the

present world. The navigation system plays a very vital part in

our life and as the world is developing the precision of these

GNSS system has very important. [2] Keeping these concept in

mind many countries have already developed their own GNSS

system. Our aim is to utilize these GNSS system to develop a

precise navigation system in the Asia-pacific region where

most countries belong to the third world countries.

2. GLOBAL NAVIGATION SATELLITE

SYSTEMS (GNSS)

2.1 GPS

GPS provide the user with a three-dimensional positioning

solution (longitude, latitude and altitude) to high precision

(within a few meters) using time signal transmitted along a line

of sight by radio from satellites.[5] GPS is a one-way ranging

(passive) system and it provides continuous positioning and

timing information, anywhere in the world. GPS satellites are

arranged so that four satellites are placed in each of six orbital

planes. With this constellation geometry, four to ten GPS

satellites will be visible anywhere in the world, if an elevation

angle of 10° is considered.[9] The orbits are nearly circular and

equally spaced around the equator at a 60° separation with a

nominal inclination relative to the equatorial plane of 55°. The

nominal orbital period of a GPS satellite is one half of a sidereal

day or 11 hours, 58 minutes. In each plane there are four

operational satellites.[7] There are 10 different GPS navigation

signals, broadcast across three bands, known as link 1 (L1), link

2 (L2) and link 5 (L5). The carrier frequencies are 1575.42

MHz for L1, 1227.60 MHz for L2 and 1176.45 MHz for L5,

while the declared double-sided signal bandwidth is 30.69

MHz in each band.

2.2 Galileo

Galileo system consists of 30 satellites (27 operational + 3

active spares), positioned in three circular medium earth orbit

(MEO) planes at 23,222 km altitude above the earth and at an

inclination of the orbital planed of 56 degrees to the equator.

The nominal orbit period is 14 hours, 5 minutes giving 1.7

orbits per sidereal day.[7] Galileo broadcasts 10 different

navigation signals across three frequency bands E5, E6 and E1-

L1-E2. The E5 band is 92.07 MHz (90 x 1.023 MHz) wide and

centered at 1191.795 MHz. It is partitioned into E5a and E5b

sub bands, with carrier frequencies of 1176.45 and 1207.14

MHz, respectively. The E6 and E1-L1-E2 bands are both 40.92

MHz wide and centered at 1278.75 and 1575.42 MHz,