Jeroen Zomerdijk

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GLONASS: Wat brengt het ons? Leica Geosystems b.v. Jeroen Zomerdijk 2 Content GLONASS benefits in position / height improvement Hardware Biases of GLONASS System 1200+ GNSS Corporate Conclusions

description

Leica en GLONASS

Transcript of Jeroen Zomerdijk

Page 1: Jeroen Zomerdijk

GLONASS: Wat brengt het ons?

Leica Geosystems b.v.Jeroen Zomerdijk

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Content

� GLONASS benefits in position /

height improvement

� Hardware Biases of GLONASS

� System 1200+ GNSS

� Corporate

� Conclusions

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GLONASS: Benefits

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GLONASS: Benefits

General Characteristics – Availability Nov 2007• 17 operating satellites

• At least 7 satellites GPS+GLONASS all the time with cut off 10°

• GPS only has minimum of 5 satellites needed for ambiguity fixing RTK

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GPS only

� At least 5 GPS satellites are necessary to get a high accuracy (fixed) solution.

Combined GPS and GLONASS

� At least 5 GPS or 4 GPS + 2 GLONASS satellites are necessary to get a high accuracy (fixed) solution.

� Benefit of GPS + GLONASS on a statistical basis (open sky environment, urban canyons, tree environment, kinematic data, long static baseline)

Approx. 15 % !

GLONASS: Benefits

Ambiguity Resolution Nov 2007

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GLONASS: Benefits

Better Geometry Nov 2007Example Vertical Dilution of Precession (VDOP)

• VDOP is indicator for achievable height accuracy. Large VDOP low

height accuracy

• GPS only VDOP goes up to 4

• Combined GPS/GLONASS: VDOP always below 2.5

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10 10.5 11 11.5 12 12.5 13 13.5 14474.25

474.3

474.35

474.4

474.45

474.5

Time [h]

Height [m

]

15km Baseline

GPS

GPS+GLONASS

10 10.5 11 11.5 12 12.5 13 13.5 144

6

8

10

12

14

Time [h]

# Sats

GLONASS: BenefitsHeight Accuracy with and without GLONASS Nov 2007

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� Percentage Ambiguity-Resolution

(continuous re-initialisation)

Project BL Length (m) GPS [%] GPS/GLONASS [%]

IGS Stations 149,152 53.31 61.76

Train 30 55.89 90.49

Tree 19,874 72.73 100

Static 2,053 97.06 99.22

GLONASS: Benefits

Ambiguity Resolution

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GLONASS: Benefits

General Characteristics – Availability Now• Currently 20 operating satellites (March 27, 2009)

• At least 12 satellites GPS+GLONASS all the time with cut off 10°

• GPS only has minimum of 7 satellites

• Larger number of satellites yields higher

accuracy

• GLONASS stabilizes GPS geometry => higher

accuracy

• Combined GPS/GLONASS more satellites

available for reliable ambiguity fixing in RTK

• Performance enhancement about 15%

compared to GPS only operation

GLONASS Benefits

Summary

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Interoperability of GLONASS observations for RTK

positioning applications

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Content

� Hardware Biases

� Impact on RTK Applications

� Elimination of Hardware Biases

� Conclusion

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� 1982: Launch of 1st satellite

� 1995: Full Constellation

� End of 90s:

� Financial problems

� Problems with satellite lifetime

� 2001: Only 7 satellites available

� Since 2006: Financing secured

� Since 2007: Number of yearly

satellite launches increased to 6

GLONASS

History

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Combined GPS/GLONASS Processing

Advantages

� More satellites available

� Better geometry

� Result

� More fixed epochs

� Higher Accuracy, reliability

But …

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Antenna electronics

Receiver electronicsAntenna cable

GNSS Observations

Hardware Biases

pm

pm

pm

pm tctcP εδδρ ++−=

Measurement

True distance

Receiver clock error

Satellite clock error

Noise

Satellite p

Station m

Distance ρ

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Antenna electronics

Receiver electronicsAntenna cable

Hardware Bias

pm

pm

pm

pm

pm cHtctcP εδδρ +++−=

GNSS Observations

Hardware Biases

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Zero Difference

pm

pm

pm

pm

pm cHtctcP εδδρ +++−=

GNSS Observations

Zero, Single and Double Differences

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Zero Difference

Single Difference

� Satellite clock error is eliminated

pm

pm

pm

pm

pm cHtctcP εδδρ +++−=

pnm

pnmnm

pnm

pnm cHtcP ,,,,, εδρ ++−=

m n

GNSS Observations

Zero, Single and Double Differences

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Zero Difference

Single Difference

� Satellite clock error is eliminated

Double Difference

� Receiver clock error is eliminated, Hardware bias remains

pm

pm

pm

pm

pm cHtctcP εδδρ +++−=

pnm

pnmnm

pnm

pnm cHtcP ,,,,, εδρ ++−=

pq

inm

pq

inm

pq

nm

pq

inm cHP,,,,,,,

ερ ++=

m n

p q

GNSS Observations

Zero, Single and Double Differences

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Hardware Biases

Frequency DependencyGPS

� All satellites send different code on identical frequencies (CDMA)

� Same hardware bias for all satellites

GLONASS

� All satellites send identical code on different frequencies (FDMA)

� Different hardware bias for each satelliteGLOGPS

GLOGPS HHff ≠⇒≠

qGLOpGLOqGLOpGLO HHff

,,,, ≠⇒≠

qpGPSqp HHfff =⇒==

PSD of L1 code

Frequency [MHz]

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Impact of Hardware Biases

Example: Zero-Baseline, DD Code

Time [h]

DD Code residuals [m]

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Impact of Hardware Biases

Example: Relative Measurements to 2 Satellites

Station m

� Different Hardware Bias for satellite p and q

Station n

� Different Hardware Bias for satellite p and q

m n

p q

Station m and n

� Identical Hardware Biases for all satellites if identical

hardware!

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0, =⇒= pnm

pn

pm HHH

m n

p

Impact of Hardware Biases

Example: Identical Hardware

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Time [h]

DD Code residuals [m]

Impact of Hardware Biases

Identical Hardware, Zero Baseline, DD Code

Identical Hardware

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Time [h]

DD Code residuals [m]

Impact of Hardware Biases

Identical Hardware, Zero Baseline, DD Code

Mixed Hardware

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Time [h]

DD Phase residuals [m]

Time [h]

DD Phase residuals [m]

Impact of Hardware Biases

Zero Baseline, DD Phase Observations

Mixed Hardware Identical Hardware

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GLONASS Biases

Calibration and Correction in Real Time

Preface

� Reference receiver type transmitted in various correction formats like RTCM 3

Implementation

� Rover detects reference receiver type and corrects reference observations in real time

� Alternatively: reference receiver type is set manually on the rover. Again the rover

corrects reference observations in real time

since version 7.0

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GLONASS Biases

Real Time Correction

Time [h]Time [h]

DD Phase residuals [m]

Mixed Hardware Identical Hardware

Time [h]

Mixed Hardware

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• RTK users profits via RTCM format of

elimination of GLONASS hardware biases

• Improvement of quality

• Benefit for mixed hardware for rover users

GLONASS Benefits

Summary

System 1200+ GNSS

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2008 2015

Leica, GNSS Surveying and Future Satellite Signals

Surveying with GNSS in 2016 …

• 31 GPS and 16 Glonass

• 2 Frequencies (L1, L2)

• 26 observations per epoch on

average in open sky

• 12 observations per epoch with

obstruction

• RTK up to 30km

• 8“ typical initialisation time

• RTK accuracy ±15mm

• 32 GPS, 24 Glonass, 30 Galileo +

Compass

• 3 Frequencies (L1, L2, L5)

• >80 observations per epoch on

average in open sky

• ~30 observations per epoch with

obstruction

• RTK up to 50km

• 1“ typical initialisation time

• RTK accuracy ±10mm

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GPS L5, Galileo, Compass and Leica System....before L5 will be up there

...fully capable of GPS, GLONASS, Galileo and Compass!!

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Future Proof Most Accurate Most FlexibleProperties

• GPS L1, L2 (C/P)

• GPS L5

• GLONASS

• Galileo

• Galileo–AltBOC signal

• Compass

• Single Base

• Full Network Rover

• Open Interface OWI

• Partner–Software on Board

• Backpack Solution

• All-on-Pole

• SmartWorx

• SmartRTK+ Technology

(Highest Consistencyin Networks)

• RTCM 3.1 correction

• SmartCheck+ Technology

(Continuous Ambiguitycheck)

• SmartTrack+ Technology

(Robust Signaltracking)

• SmartPole

• SmartStation

Features

Investment holds its valueAdvantage

GPS1200+ THE ONLY FUTURE PROOF GNSS

Customer saves moneyBenefit

Leica Geosystems

- when it has to be right

Corporate

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From space to nano technology

Technology

Space Macro Micro Nano

< 100 µm < 0,3 µm< 10 Meters < 20 µm

- GPS/GNSS- Laser Scan- Laser Track- Laser Radar- Optics- Photogram

- Laser Scan- Laser Track- Laser Radar- Photogram- Optics- Tactile- PS

- 3D Tactile- 2.5D Vision

- Light- Micro Optics

< 10.000 km

Reach

Measuring Precision

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� One

point

Today’s technologies for fast, efficient data capture

� Image-based

TPS

GPS

DISTOTM

Laser Scanning

Point-cloud Management

Aircraft-based

Remote sensing

Photo-grammetry

� Millions of

points

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We measure our success by yours:

customers define the world we live in

Building the tallest bridge in the world

With pylons reaching 343 meters (1,115

feet) in height, the Viaduct de Millau near

Montpellier in southern France is the

tallest bridge in the world – 19 meters

(62 feet) taller than the Eiffel Tower.

Leica Geosystems TotalStations with

integrated GPS positioning were used in its

construction, and for the continuous post-

construction monitoring of this record-

breaking structure.

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We measure our success by yours:

customers define the world we live in

The “Eighth Wonder of the World” gives up

its secret

For 1500 years, the Hagia Sofia in Istanbul

has confounded expert analysis of its

design. Its enormous dome is 56 meters

(184 feet) high and 34 (111 feet) meters

wide, supported on just four pillars.

Now, Leica Geosystems high definition laser

surveying equipment has revealed the elegant

and ingenious design behind the structure’s

astonishing stability.

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We measure our success by yours:

customers define the world we live in

Monitoring Burj Dubai, tallest building in

the world

� Leica Geosystems’ solutions deliver accurate positioning data for construction set out at the top level of the formwork

� Leica Geosystems Instruments and Software:

� Network of Leica NIVEL220

� Leica GRX1200 Pro Reference Stations

� Leica GX1220 as Rover equipment

� Leica TPS1205

� Leica GPS Spider and GNSS QC software

� Leica Geo Office processing software

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Leica Geosystems:

Technologies for every workflow

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Pioneer and market leader

with the most comprehensive range of solutions

� Surveying

� Civil engineering

� Monitoring

� Construction

� Machine control

� Mobile mapping

� Mining and extraction

� Real estate

� Agriculture, forestry andland management

� Industrial solutions

� ….

• Larger number of satellites yields higher

accuracy. -> even more valid with full GNSS

systems; GPS L5, Glonass, Galileo and

Compass.

• Hardware biases correctly handled between

different satellite systems or receiver types

• 1200+ receivers tracks all these GNSS satellite

systems, now and future

• Leica Geosystems dedicated global company

for broad range of precise measurements, all

types of solutions and workflows.

Leica Geosystems Benefits

Conclusions