GLOBAL POSITIONING SYSTEM

1. GOVERNMENT POLYTECHNIC RAJKOT
•CIVIL ENGINEERING-
• SURVEYING(3330605)
• TOPIC ---- GPS SYSTEM IN SURVEYING
• (GPS PARTS, SEGMENTS,
ADVANTAGE,APPLICATION,RECEIVERS,MEASURE
TECHNIQUES,MAPS)
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2. Global Positioning System (GPS)
• The Global Positioning System (GPS) is a satellite-based navigation and
surveying system for determination of precise position and time, using
radio signals from the satellites, in real-time or in post-processing mode.
GPS is being used all over the world for numerous navigational and
positioning applications, including navigation on land, in air and on sea,
determining the precise coordinates of important geographical features as
an essential input to mapping and Geographical Information System (GIS),
along with its use for precise cadastral surveys, vehicle guidance in cities
and on highways using GPS-GIS integrated systems, earthquake and
landslide monitoring, etc. In India also, GPS is being used for numerous
applications in diverse fields like aircraft and ship navigation, surveying,
geodetic control networks, crustal deformation studies, cadastral surveys,
creation of GIS databases, time service, etc., by various organizations.
• conventional techniques, and the economy of operations make GPS the
most promising surveying technique of the future. With the well-
established high accuracy achievable with GPS in positioning of points
separated by few hundreds of meters to hundreds of km, this unique
surveying technique has found important applications in diverse fields. 2S M TILALA G P RAJKOT

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5. Global Positioning System (GPS)
• The Navigation Satellite Timing and Ranging Global Positioning System
(NAVSTAR GPS)developed by the U.S. Department of Defense (DoD)
to replace the TRANSIT Navy Navigation Satellite System (NNSS) by
mid-90’s, is an all-weather high accuracy radio navigation and
positioning system which has revolutionized the fields of modern
surveying, navigation and mapping. For every day surveying, GPS has
become a highly competitive technique to the terrestrial surveying
methods using theodolites and EDMs; whereas in geodetic fields, GPS
is likely to replace most techniques currently in use for determining
precise horizontal positions of points more than few tens of km apart.
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6. Global Positioning System (GPS)
• The GPS, which consists of 24 satellites in near circular orbits at about
20,200 Km altitude, now provides full coverage with signals from
minimum 4 satellites available to the user, at any place on the Earth.
By receiving signals transmitted by minimum 4 satellites
simultaneously, the observer can determine his geometric position
(latitude, longitude and height), Coordinated Universal Time (UTC)
and velocity vectors with higher accuracy, economy and in less time
compared to any other technique available today
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7. GPS Segments
• The Global Positioning System basically consists of three segments:
the Space Segment, The
• Control Segment and the User Segment.
• 2.3.1 Space Segment
• The Space Segment contains 24 satellites, in 12-hour near-circular
orbits at altitude of about 20000 km, with inclination of orbit 55°. The
constellation ensures at least 4 satellites in view from any point on
the earth at any time for 3-D positioning and navigation on world-
wide basis. The three axis controlled, earth-pointing satellites
continuously transmit navigation and system data comprising
predicted satellite ephemeris, clock error etc., on dual frequency L1
and L2 bands
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8. THE GPS SYSTEM
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9. GPS Segments
Control Segment
• This has a Master Control Station (MCS), few Monitor Stations (MSs) and
an Up Load Station (ULS). The MSs are transportable shelters with receivers
and computers; all located inU.S.A., which passively track satellites,
accumulating ranging data from navigation signals. This is transferred to
MCS for processing by computer, to provide best estimates of satellite
position,velocity and clock drift relative to system time. The data thus
processed generates refined information of gravity field influencing the
satellite motion, solar pressure parameters, position, clock bias and
electronic delay characteristics of ground stations and other observable
system influences. Future navigation messages are generated from this and
loaded into satellite memory once a day via ULS which has a parabolic
antenna, a transmitter and a computer. Thus, role of
• To estimate satellite [space vehicle (SV)] ephemerides and atomic clock
behavior.
• - To predict SV positions and clock drifts.
• - To upload this data to SVs.
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10. GPS Segments
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11. GPS Segments
• User Segment
• The user equipment consists of an antenna, a receiver, a data-
processor with software and a control/display unit of automatic clock.
The GPS receiver measures the pseudo range, phase and other data
using navigation signals from minimum 4 satellites BUT NOW A DAYS
12 RECEIVER CHANEL and computes the 3-D position, velocity and
system time. The position is in geocentric coordinates in the basic
reference coordinate system: World Geodetic reference System 1984
(WGS 84), which are converted and displayed as geographic, UTM,
grid, or any other type of coordinates. Corrections like delay due to
ionosphere and tropospheric refraction, clock errors, etc. are also
computed and applied by the user equipment / processing software..
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12. Features of GPS Satellites
• - Design Life: 5 years (with expendables stored for 7 years) - On orbit
weight: 430 kg - End-of-life power: 400 W - Power Source: 5m2 solar arrays
tracking the sun and 3 Ni-cd batteries for eclipse - 3 axis established, earth
pointing satellites - Navigation Pay Load: Pseudo Random Noise (PRN)
signal assembly, atomic frequency standard - Caesium beam atomic Clocks
accurate to 10-14 sec, processor and L band antenna - Codes: (a) Precision
(P) Code: Generated at GPS clock frequency of 10.23 MHz (equivalent to 30
m in range) interpolated to sub-meter level. Repeats itself after 267 days,
resolution = 100 nanoseconds.
• (b) Coarse Acquisition (C/A) Code: Code sequence frequency of 1.023 MHz
(range 300 m) interpolated to few m. Repeats itself every 1 millisecond,
resolution = 1 micro second - PRN navigation signals on two frequencies:
• (a) 1575.42 Mhz - L1 Band - Wave length 19 cm.
• (b) 1227.6 MHz - L2 Band - Wave length 24 cm.
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13. Advantages of GPS
• VEHICLE NAVIGATOR used in road, water way , air way , its gives
location, speed, direction, time of vehicles.
• Mobile or laptop get distance and direction of any object as well as
location in road, water way , air way.
• Its working 24 hr
• No need manpower on working
• It required less time to perfect location information
• High accuracy at 10 mm
• No harmful effect of environment
• PANIC BUTTON for user to used at hazardous or accidental emergency
situation like hijack
• Threaten(stolen) of vehicles easily find out in anywhere
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14. APPLICATIONS OF GPS
• Establishment of high precision zero order Geodetic National Survey Control
Network of GPS stations.
• - Strengthening, densification and readjustment of existing Primary
Control Networks using GPS stations.
• - Connecting remote islands to mainland Geodetic Control Networks. -
Determination of a precise geoids using GPS data.
• - Earth rotation and Polar Motion Studies from GPS data.
• - Estimating gravity anomalies using GPS.
• - Marine Geodesy : positioning of oceanic stations, buoys etc.
• - Earthquake monitoring : Crustal movements of the order of few
cm/year can be monitored using GPS method, thus making GPS most
suitable for monitoring continental drifts, neotectonic / seism
tectonic movement, etc.
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15. APPLICATIONS OF GPS
Vertical Control Network : High accuracy of few mm in heights achievable with GPS at
much less cost and time compared to levelling to make GPS method most suitable
for establishing lower accuracy vertical control networks.
- Geophysical positioning, mineral exploration and mining.
Survey control for topographical and cadastral surveys.
Ground control for photogrammetric control surveys and mapping. Offshore
positioning : Shipping, offshore platforms, fishing boats etc.
• Timing :- GPS timing user like Astronomers ,computer network, radio and T.V,
BANK, POWER COMPONER, COMMUNICATION SYSTEM
• General aircraft navigation, approach to runways, navigation/positioning in remote
areas like deserts, dense jungles, shaded areas of microwave, precise sea
navigation, approach to harbours etc
• Military ; Improved weapon delivery accuracies i.e. for missiles etc., for
ranging in artillery, navigation for Army, Navy, Air force - thus
affecting ultimate saving of up to 1 billion dollars annually on navigation in
INDIA
• - Scientific applications, like studies related to the ionosphere and
troposphere, glaciology, etc.
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16. GPS RECEIVERS
• Its monitoring of all satellite above earth
• Its has antenna processer and automatic clock.
• Showing of users location, speed, direction, time in channel in earlier
have 4 channel but now has 12
• Receivers like mobile, wrist watch, car ,ship, air craft etc..,
• Mostly we used hand held receivers in general.
• Types of receivers;
• TYPES 1 : used in car navigation with no screen name RS 232 receiver
or GPS MICE. For connecting with Bluetooth or computer wire .
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17. GPS RECEIVERS
• TYPES 2 : displayed screen like speed ,direction, time, location. At
store of data with computer attachment. Used in steamer, sheep,
port. At instrumental like altimeter, electric compass, radio
transmitter, barometer.
• TYPES 3 : same as above but data storage capacity large . So used in
office work for listed purposes .
• Agriculture ,surveying, military, mapping, GIS, oil and gas , public
places
• TYPES 4 : used in car map network. but not updated.
• TYPES 5 : used in micro work like in small chip for tracking in forest
animal calculation of population, car ,games
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18. GPS MEASURING TECHNIQUES
• STATIC SURVEYS
• RAPID STATIC SURVEYS
• KINEMATIC SURVEYS
• REAL TIME KINEMATIC SURVEYS
• STATIC SURVEYS
• Firstly developed .
• For measuring of 20 km long base line, geodetic network. Plate tectonic networks.
• More accuracy take more time
• one point reference receiver and other are rover well positioned 5 satellite set of
1 hour observation ,taken one by one observation. In figure
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19. STATIC SURVEYS
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20. RAPID STATIC SURVEYS
IT HAS ONE REFERANCE POINT AND MORE ROVERS. USED FOR NETWORK
DENSIFICATION,ESTABLISHING LOCAL CONTROL NETWORK. ITS QUICK AS THEN STATIC .
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21. KINEMATIC SURVEYS
• Its used for detailed surveying for more points measurement. Firstly
reference and rover switch on to 5-20 minutes then initialization.
Freely moves on another point on map called kinematic chain.
ROVER
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22. REAL TIME KINEMATIC SURVEYS
• Kinematic on the fly ; it is a Conversation of K.S no need
initialization. Done at real-time so both data set rover working
together also correction required easily .
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23. GPS MAPS(RASTER MAPS AND VECTOR MAPS)
• RASTER MAPS: its connecting of all pixels on paper with scanning .its
to reproducing image like shading, colouring,countouring,whith out
changing of resolution. Used in TRAX, NATIONAL GEOGRAPHIC,
MAPTECH,FUGAWI. Its not load on any GPS .
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24. GPS MAPS
• Difference between raster and vector maps
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25. VECTOR MAPS
• Its simple instruction based on program.
• Indicating like names, words, places, phrases. Its load in GPS.
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26. ANDROID MAPS USED BY GPS
• STREET MAP: for city ,road network, position.
• TOPOGRAPHIC MAP: for natural like mountain ,river, forest.
• AERIAL PHOTOGRAPHY : for capturing land image as well as military
operation, but now environmental ,climate changes also considering
in.
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27. REFERENCES
• IMAGES FROM GOOGLE IMAGE.
• BOOKS ---SURVEYING VOLUME 1 MC Grew Hill Education.
• (PROF. S. K. DUGGAL)
• SURVEYING VOLUME 1 LAXMI PUBLICATION
• (DR. B. C. PUNAMIYA)
• SURVEYING PRACTICES KATSON PUBLICATION.
• (DR. NARAYAN R. CHANDAK)
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