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Global Navigation Satellite Systems, Receivers and Equipment

Global Navigation Systems

GLONASS

GALILEO

COMPASS (Beidou)

Receivers and Equipment

Handheld Receivers

Survey-Grade Receivers

Related Equipment

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At the end of the 1960's the military identified a need for a Satellite Radio Navigation

System (SRNS) for use in precision guidance of the planned new generation of ballistic

missiles.

The existing Tsiklon satellite navigation system requires several minutes of observation

by the receiving station to fix a position.

In 1968 to 1969 research institutes of the Ministry of Defense, Academy of Sciences, and

Soviet Navy worked together to establish a single solution for air, land, sea, and space

forces.

This resulted in a 1970 TTT requirements document that established the requirements

for such a system. After further basic research in 1976 a decree was issued by the Soviet

state for establishment of the GLONASS (Global Navigation Satellite System).

GLObal'naya NAvigatsionnaya

Sputnikovaya Sistema

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DATE LAUNCHED SATELLITE

12 October 1982 Cosmos 1413

10 August 1983 Cosmos 1492

29 December 1983 Cosmos 1521

19 May 1984 Cosmos 1554

04 September 1984 Cosmos 1595

18 May 1985 Cosmos 1650



24 April 1987 Cosmos 1838


17 February 1988 Cosmos 1919

21 May 1988 Cosmos 1947


10 January 1989 Cosmos 1988

DATE LAUNCHED SATELLITE

31 May 1989 Cosmos 2023

19 May 1990 Cosmos 2080



30 January 1992 Cosmos 2179

30 July 1992 Cosmos 2206

17 February 1993 Cosmos 2235


11 August 1994 Cosmos 2288

20 November 1994 Cosmos 2294

07 March 1995 Cosmos 2308

24 July 1995 Cosmos 2316



13 October 2000 Cosmos 2375

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DECAY

disintegration of the Soviet Union in 1991

Russia was unable to maintain the system

only eight satellites remain in operation (April 2002)

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RESTORATION AND MODERNIZATION

special-purpose federal program named

"Global Navigation System"

the GLONASS system was to be restored to fully deployed status

(i.e. 24 satellites in orbit and continuous global coverage) by 2011

October and December 2007: lifted the final

six second-generation satellites

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Prototypes (Generation zero)

The first GLONASS vehicles launched, referred to as Block I vehicles,were prototypes and GVM dummy vehicles. Designed to last only oneyear, many averaged an actual lifetime of 14 months.

First generation

The true first generation of Uragan satellites were all 3-axis stabilizedvehicles, generally weighing 1,250 kg and were equipped with amodest propulsion system to permit relocation within theconstellation.

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Second generation

The second generation of satellites, known as Uragan-M (also calledGLONASS-M)These satellites possess a substantially increased lifetime of sevenyears and weigh slightly more at 1,480 kg.They are approximately 2.4 m in diameter and 3.7 m high, with a solararray span of 7.2 m for an electrical power generation capability of1600 watts at launch.

Third generation

The third generation satellites are known as Uragan-K (GLONASS-K) spacecraft. These satellites are designed with a lifetime of 10 to 12 years, a reduced weight of only 750 kg, and offer an additional L-Band navigational signal.

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GLONASS SYSTEM DESIGN

1. The SPACE SEGMENT

• The orbit period of each satellite is approximately 8/17 of a sidereal day such that,

• Because each orbital plane contains eight equally spaced satellites

• The satellites are placed into nominally circular orbits with target inclinations of 64.8degrees and an orbital height of about 19,123 km, which is about 1,060 km lower than GPS satellites.

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The GLONASS satellite signal identifies the satellite and provides:

1. the positioning, velocity and acceleration vectors at a reference epoch for computing satellite locations

2. synchronization bits3. data age4. satellite health5. offset of GLONASS time6. almanacs of all other GLONASS satellites.

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1. The CONTROL SEGMENT

•consists of the system control center and a network of command tracking stations across Russia.

• similar to GPS, must monitor the status of satellites, determine the ephemerides and satellite clock offsets with respect to GLONASS time and UTC (SU) time, and

•twice a day upload the navigation data to the satellites

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1. The USER SEGMENT

•The User Segment consists of equipment (such as a NovAtelMiLLennium-GLONASS GPSCard receiver) which tracks and receives the satellite signals. This equipment must be capable of simultaneously processing the signals from a minimum of four satellites to obtain accurate position, velocity and timing measurements.

•GLONASS is a dual military/civilian-use system. Selective availability, however, will not be implemented on GLONASS C/A code.

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1. The USER SEGMENT

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DATUM

•The satellite coordinates are given in the PZ-90 (Parametry Zemli 1990) geodetic datum. Until the 1993, the “Soviet Geodetic System 1985”(SGS 85) was in use.

•GLONASS ephemerides are referenced to the ParametryZemli 1990 (PZ-90 or in English translation, Parameters of the Earth 1990, PE-90) geodetic datum.

• The realization of the PZ-90 frame has resulted in offsets in origin, orientation and difference in scale with respect to WGS 84 used by GPS.

•Relationships between the PZ-90 and WGS 84 have now been established.

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PARAMETRI ZEMLI 1990

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GLONASS TIME VS. LOCAL RECEIVER TIME

•GLONASS time is based on an atomic time scale similar to GPS.

•This time scale is Universal Time Coordinated as maintained by the former Soviet Union (UTC(SU)).

•Unlike GPS, the GLONASS time scale is not continuous and must be adjusted for periodic leap seconds.

•GLONASS time is maintained within 1 ms of UTC(SU) by the control segment with the remaining portion of the offset broadcast in the navigation message.

•GLONASS time is offset from UTC(SU) by +3 hours due to control segment specific issues.

Leap seconds are applied to all UTC time references about every other year as specified by the IERS. Leap seconds are necessary because the orbit of the earth is not uniform and not as accurate as the atomic time references.

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TRANSFORMATION from PZ90 to WGS84

•(x,y,z) -desired WGS-84 coordinate set•(u,v,w) -given coordinate set in PZ90•(Δx, Δy, Δz) –origin offset •(δs) –linear scale factor •(ε,Ф,ω) –small angle rotations given in radians•u,v and w - axes

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TRANSFORMATION from PZ90 to WGS84

•There are a number of different transformations that have been published but the majority of them are optimizedfor the particular region of the planet that the data was collected in.

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Parameter Detail GLONASS GPS

Satellites Number of satellites

Number of orbital planes

Orbital plane inclination

Orbital radius (kilometers)

21 + 3 spares

3

64.8

25510

21 + 3 spares

6

55

26560

Signals Fundamental clock frequency (MHz)

Signal separation technique1

Carrier frequencies (MHz) L1

Code clock rate (MHz) C/A

P

Code length (chips) C/A

P

5.0

FDMA

1602.0-1615.5

0.511

5.1

511

5.11 x 10^6

10.23

CDMA

1575.42

1.023

10.23

1023

6.187104 x 10^12

PC/A-code

Navigation

Message

Superframe duration (minutes)

Superframe capacity (bits)

Superframe reserve capacity (bits)

Word duration (seconds)

Word capacity (bits)

Number of words within a frame

Technique for specifying satellite

ephemeris

Time reference 2

Position reference (geodatic datum) 3

2.5

7500

~620

2.0

100

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Geocentric Cartesian

coordinates and their

derivatives

UTC(SU)

PZ-90

12.5

37500

~2750

0.6

30

50

Keplarian orbital

elements and

perturbation factors

UTC (USNO)

WGS 84

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GalileoPositioningSystem

ang.dumayas.locsin.villanueva

1999 Concepts from originally four countries (Germany,

France, Italy, UK), then reduced to a joint team from all four countries.

Intended primarily for civilian use (at full precision).

2001 US Government wrote to EU opposing project.

Galileo is declared as “almost dead”.

EU member states decided importance of having own independent satellite-based positioning and timing infrastructure.

2002 EU and European Space Agency agrees to fund project.

2003 First stage of project agreed upon officially (May 26). Starting cost (end of 2005) estimated at € 1.1 billion. 30 planned satellites from 2006-2010. Final estimated cost at € 3 billion (includes earth

infrastructure). China joins project, investing € 230 million.

2004 Agreement with US to switch to modulation BOC(1,1)

(Binary Offset Carrier 1.1). Israel becomes a partner in project.

2005 Ukraine, India, Morocco, and Saudi Arabia join

project.

2006 South Korea joins project.

2007 Project in “deep crisis”, having successfully

launched only 1 of 30 intended satellites. Funds reallocated from EU’s agriculture and

administration budgets. Project moves forward, agreeing on plans for bases

in Germany and Italy.

Galileo satellites 30 spacecraft orbital altitude: 23,222 km (MEO) 3 orbital planes, 56° inclination (9 operational

satellites and one active spare per orbital plane) satellite lifetime: >12 years satellite mass: 675 kg satellite body dimensions: 2.7 m x 1.2 m x 1.1 m span of solar arrays: 18.7 m power of solar arrays: 1,500 W (end of life)

Two on-board atomic clocks developed for Galileo:

a Rubidium Atomic Frequency Standard frequency: 6 GHz

a Passive Hydrogen Maser frequency: 1.4 GHz

GALILEO RUBIDIUM CLOCK

HYDROGEN MASER CLOCK

http://www.esa.int/esaNA/SEMTK50DU8E_galileo_1.html

The Galileo Satellite Dish - Stationary SystemThe Galileo VSAT Technology Satellite Dish is a 1.2 meter dish with a 2-or 4-watt transmitter. The dish size provides compensates for rain-fade (degrading/lost signal in a rain storm). System is normally mounted on a non-penetrating roof mount for stationary installation.

The Galileo Satellite Dish - Mobile SystemThe Galileo mobile dish is a .95 square meters with a 2 or 4 watt transmitter.

Dish Specifications:1.2 meter. Temperature range -30° to +60° C ambient air. Relative humidity 1 to 100%. Rain up to 2 cm/hr.

Radio Transmitter:2 Watts. Temperature range -30° to +55° C ambient air. Relative humidity 1 to 100%. Rain up to 2 cm/hr.

Cable Run:Up to 300 ft from the dish to In-Door unit with Beldin Coax.

INDOOR EQUIPMENT Satellite Gateway:

The Galileo Gateway (a 1RU rackmount box) is the only indoor equipment needed for the system. It contains both the satellite modems (send-and-receive) as well as a web based gateway that can connect to your network router.

Size:Height: 1.75"(4.45cm) Width: 17.0"(43.18cm)Depth: 10.5"(26.67cm)

Weight:10.5lbs (4.75kg)

Power:100 to 240 VAC Auto Detect, 50-60 Hz, 138-180 Max Watts

HDD:Flash Memory (No Hard Drive)

Operating Temperature:0° to +40° C (32° to 104° F)

Humidity:0 to 95% non-condensing

Physical Interface:RJ-45 10/100 BaseT EthernetSupports popular routing protocols: RIP, RIPv2, BGP, OSPF, EIGRP

Coverage Map:The Galileo Class Satellite (AMC-4) has an extremely large footprint that covers most all of North America, Central America and the Caribbean. This KU band bird is situated at a longitude of 101 degrees.

NOC:100% Network Redundancy/ Backup solutions at the Hub

Operations:365/24/7 Active Network Management and monitoring

Hub Locations:San Diego, California (AMC4)Vienna, Virgina (AMC4 Backup)Mexico City, Mexico (SatMex6)Amsterdam, Netherlands (Telstar12)

Satellite:AMC4 at 101 W - North AmericaSatMex6 at 113 W - Mexico / Central AmericaTelstar 12 at 15 W - Europe / North Africa / Middle East

Platform:TDMA

Galileo – North American Coverage

Galileo satellite test beds: GIOVE

http://en.wikipedia.org/wiki/Image:Giovea.jpg

GSTB-V1 (Galileo System Test Bed Version 1)

Led by ESA and European Satellite Navigation Industries

Validated the on-ground algorithms for Orbit Determination and Time Synchronisation (OD&TS)

Provided industry with fundamental knowledge to develop the mission segment of GALILEO

GIOVE-A -first GIOVE (Galileo In-Orbit Validation Element) test

satellite-built by Surrey Satellite Technology Ltd (SSTL) and was

successfully launched on 28 December 2005 by the European Space Agency and the Galileo Joint

-placed in the first orbital plane from where it is being used to test the equipment on board and the functioning of ground station equipment.

-tested for the performance of the two atomic clocks on-board and measured various aspects of the space environment around the orbital plane, in particular the level of radiation

-ensured that Galileo meets the frequency-filing allocation and reservation requirements for the International Telecommunication Union (ITU), a process that was required to be complete by June 2006

GIOVE-B-built by Astrium and Thales Alenia Space,

has a more advanced payload than GIOVE-A. -successfully launched on 27 April 2008 at

22:16 GMT (4.16 a.m. (Baikonur time) aboard a Soyuz-FG/Fregat rocket provided by Starsem.

-continue the testing begun by its older sister craft, but with the addition of a passive hydrogen maser and with a mechanical design more representative of the operational satellites

GIOVE-A2

-was scheduled to be launched in the 2nd half of 2008

-meant to maintain the International Telecommunications Union (ITU) frequency filing that was secured by its predecessor and facilitate further development of ground equipment

FOUR NAVIGATION SERVICES Open Service (OS)

free for anyone to access OS signals: 1164–1214 MHz and 1563–1591 MHz. accuracy: <4 m horizontally and <8 m vertically if they use both OS bands.

<15 m horizontally and <35 m vertically using single band, comparable to what the civilian GPS C/A service provides today

Commercial Service (CS) available for a fee accuracy: better than 1 m. The CS can also be complemented by ground stations

to bring the accuracy down to less than 10 cm. Signal: three frequency bands, the two used for the OS signals, as well as at 1260–

1300 MHz.

Public Regulated Service (PRS) and Safety of Life Service (SoL) accuracy: comparable to the Open Service. main aim: robustness against jamming and the reliable detection of problems

within 10 seconds. They will be targeted at security authorities (police, military, etc.) and safety-critical transport applications (air-traffic control, automated aircraft landing, etc.), respectively.

1. More precise than GPS or GLONASS

2. Designed for commercial use

3. Requires a new receiver

4. Satellites will use a better clock

Galileo is intended to be more precise guaranteed to achieve accuracies of 1 meter, with real time accuracies to reach, under certain conditions, 10 centimeters.

Galileo will be accurate down to the metre range including the height (altitude) above sea level, and a better positioning services at high latitudes.

The Galileo system is aimed at complementing the current GPS system and enabling a higher degree of navigational accuracy for the general population. Its creators claim that Galileo will enhance accuracy to within one meter.

The new system will require a new receiver although the Europeans say that the device will be small and cheap as it is squarely aimed at the consumer market.

Although the technology is clearly just a variant of an existing model, the future looks promising for Galileo.

Already there is talk of applications for the blind, law-enforcement, customs services, the justice system, transport and logistics and also search and rescue. If nothing else this technology may just make it that bit easier for die-hard fishermen who have been such stalwarts of GPS!

2 Rubidium (Rb) and 2 Cesium (Cs) clocks were used in the GPS Block II/IIA satellites. Combination of both types is implemented for achieving redundancy and coping with a possible malfunction problem.

Galileo will use in addition to Rb clocks, a new type of clock: The Hydrogen Maser clock. It will achieve timing accuracies of 1 nanosecond (ns), whereas the Rubidium clocks achieve accuracies of 10 ns. The main functionality of these clocks is to produce the frequency from which the Navigation signal is generated.

1.Introduction

2. history and development

3. segments

4. frequencies and time frame

5 service

6. deployment

7. Principles of state policy

8. International Cooperation

“Northern Dou” – 7 brightest stars of the constellation Ursa major.

stars used to locate the North Star Polaris

Project by China

It consist of

- 5 geostationary orbit (GEO) satellites and 30 medium Earth orbit (MEO) satellites

http://en.wikipedia.org/wiki/Geostationary_orbit

http://en.wikipedia.org/wiki/Medium_Earth_Orbit

is a geosynchronous orbit directly above the Earth's equator (0° latitude)


http://en.wikipedia.org/wiki/Geosynchronous_orbit

http://en.wikipedia.org/wiki/Earth

http://en.wikipedia.org/wiki/Equator

http://en.wikipedia.org/wiki/Latitude

is the region of space around the Earth above low Earth orbit (2,000 kilometers) and below geostationary orbit (35,786 kilometers).

http://en.wikipedia.org/wiki/Medium_Earth_Orbit

http://en.wikipedia.org/wiki/Low_Earth_Orbit


Beidou -1

In September 2003, China joined the Galileo positioning system project

€230 million

http://en.wikipedia.org/wiki/2003

http://en.wikipedia.org/wiki/Galileo_positioning_system

http://en.wikipedia.org/wiki/Galileo_positioning_system

http://en.wikipedia.org/wiki/Euro

Geostationary orbit

limits the coverage to areas on Earth where the satellites are visible

The area that can be serviced is from 70°E to 140°E, and from 5°N to 55°N

The two satellites (1A,1B) were designed as experimental satellites

space segment

ground segment

user segment

Space Segment

- consists of 5 GEO and 30 MEO satellites

Ground Segment

Master Control Station

Upload Station

Monitor Station

User segment

consists of Compass user terminals, which are compatible with GPS, GLONASS, and Galileo

Beidou Time System (BDT)

COMPASS time reference

Based from atomic time which does not introduce any leap seconds.

Derived from atomic time ensemble maintained in COMPASS ground control center that can be traced from the Chinese national official time UTC(NTSC) kept by the National Time Service Center, Chinese Academy of Sciences

Traceability to UTC (NTSC) NTSC acts as back-up timing for Compass time

system

NTSC also acts as the backup timing center of the Compass system time. At present, the NTSC maintains an ensemble of 19 Agilent 5071A commercial cesium clocks, two hydrogen masers made by Symmetricom, and another two cavity-tuned hydrogen masers made by the Shanghai Astronomical Observatory (CAS). TA (NTSC) is computed with an algorithm from all of the clocks.

Traceability to UTC (NTSC)

The master clock system consists of one hydrogen maser and one microphase-stepper.

In 2006, UTC (NTSC) was kept to within ±20ns of UTC, and so through this time link network, BDT will be synchronized with UTC within an accuracy of about 100 ns.

Open Service:B1 I 1561.098

B1-BOC 1575.42B2 I 1207.14

B2-BOC 1207.14L5 1176.45 Authorized Service:

B1 Q 1561.098B1-2 1589.742B2 Q 1207.14B3 1268.52B3-BOC 1268.52

COMPASS have 4 bands

B1

B1-2

B2

B3

GPS, Glonass and Compass band comparison

Two Types

1. Open/Free Service

2. Authorized/Licensed Service

Free and open to all users

10 m positioning accuracy

20 ns timing accuracy

0.2 m/s velocity accuracy

Uses B1-I, B1-BOC, B2-BOC, L5 frequencies.

More accurate than free

Offer more reliable “authorized” Positioning, Velocity, Timing and Communications services

Uses B1 Q, B1-2, B2 Q, B3, B3-BOC frequencies.

COMPASS Navigation Demonstration System

(Beidou-1)

Four GEO satellites have been launched since 2000, the demonstration system can provide some basic services including positioning, timing, and short-message communication.

The first experimental satellite (140E) was launched on 31st October 2000.

The second experimental satellite (80E) was launched on 21st December 2000.

The third experimental satellite (110.5E) was launched on 25th May 2003.

The fourth experimental satellite (86E) was launched on 3rd Feb 2007.

COMPASS Navigation Satellite System

(Beidou-2)

The first satellite (21,500 km) was launched on 14th April 2007.

In the near future,

COMPASS will cover Asia-Pacific in 2010.

Then it will gradually expanded into a global system.

2010 Near future

Openness

Independency

Gradualness

Compatibility and Interoperable

Openness COMPASS will provide Satellite Information

Service for civil services, COMPASS applications are encouraged all over the world, open access of all direct users to the civil signals. Signals will be free of charge.

Independency COMPASS can provide services for users

independently. The construction, operation and development of

COMPASS will be independent considering national security and user benefit.

Gradualness In order to control risks, COMPASS will be

developed step by step based on technology and economy of China.

COMPASS will provide long-term continuous services for users, and improve system performance incessantly.

Compatibility and Interoperability COMPASS is willing to be compatible and

interoperable with other satellite navigation systems, and users can get better services with interoperable terminals. The development and manufacture of the interoperable terminals will be encouraged.

Signal structure and frequency selection

Geodetic and time reference

frames

Constellation configuration

Common GNSS

Compass and GPS

1st Frequency Compatibility Coordination Meeting in Geneva, June 2007

2rd Frequency Compatibility Coordination Meeting in Xi’an, May 2008

Compass and Galileo

The frequency cooperation meeting in Beijing,May 2007 .

The 1st Formal Meeting Between the Operators and Technicians in Brussel, April 2008.



frames


Common GNSS

The BDT can be traced back to UTC

The BDT is monitored in the Chinese Academy of Sciences

UTC or TAI is the time reference used by GLONASS



frames


Common GNSS

The constellation configuration affects the visibility of satellites

The combination of the said GNSS can improve the (DOP) Dilution of Precision values

(GLONASS, GPS, Galileo, COMPASS)

Handheld Receivers

Survey-Grade Receivers

Related Equipment

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•Features•Single-frequecny receiver•Submeter real-time accuracy (with SBAS)•50-cm postprocessed•220 channel•5 megapixel camera with geotagging capability

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Differential GPS Receiver

GIS Data Collection

Asset Inventory/Maintenance

Utilities (Electric, Gas, Water)

Mobile Mapping (Facility, Forest)

Marine Survey

Etc...

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Spectra Precision EPOCH 35 GNSS System Features:• cm-accuracy with RTK

positioning• WAAS/EGNOS capability• Provides 54 channels (14

L1,14 L2 GPS, 12 L1, 12 L2 GLONASS, 2 SBAS)

GPS set

receiver, antenna

Cables (antenna-to-receiver, power)

Meter rod or tape

Batteries for the receiver

Tripod

Tribrach with optical plummet

Tribrach adapter

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