[PPT] - Leadership in Location Technology Location Anywhere, Anytime Greg PowerPoint Presentation

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Leadership in Location Technology

Location Anywhere, Anytime Greg Turetzky for Stanford EE380 4/19/06

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Is Location Important? Is Location Important?

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Huge Growth in Mass Market Devices

Automotive Automotive Mobile Phone Mobile Phone Consumer Consumer Mobile Compute Mobile Compute

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From “Where am I?” to “Where are you?”

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Future Products (?)

make sure you will never be forgotten

forget-me-not panties™ have built-in GPS and unique sensor technology giving you the forget-me-not advantage.

protect her privates

Ever worry about your wife cheating? Want to know where your daughter is late at night? Need to know when your girlfriend's temperature is rising?

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Early Satellite Navigation

TRANSIT Doppler

– (aka Navsat)

1960 -1996
Polar Orbits

– 1100 Km – 106 minutes

5 to 10 Satellites

– Observe multiple measurements off of 1 Satellite

Primarily used by Polaris submarines to reset their inertial guidance systems.

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A Short History of GPS

1973 Defense Navigation Satellite System (DNSS) passes Defense Systems Acquisition Review Council (DSARC) 1978 (Feb 22) PRN #1 Successfully Launched 1970 2000 1980 1990 1982 GLONASS #1 Launched 1990 Selective Availability Activated 1994 GPS Declared fully active

1994 – FAA awards contract for Wide

Area Augmentation System (WAAS) 1995 – SiRF Started

1986 – Motorola 4 Channel Eagle ($19K, 22 W)

Q 2004 SiRF surpasses 10MU

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GPS - SPACE SEGMENT

24 satellites + 3 active spares
6 orbital planes at 55°, 12 hour orbits, 20,000 km

nominal altitude

Free worldwide coverage
Continuous signal - all weather
L1 = 1575.42 MHz, L2=1227.6 MHz
PRN C/A (L1) and P (L1 & L2)
Continuous navigation message (satellite

ephemeris and almanac data)

Measurement Data

– Pseudo-range (distance to the Sv) – Carrier phase (wavelengths )

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GPS Satellite

GPS Antenna right-hand Circular Polarized (60W) “Event” Detector Uplink Antenna Power Cells Positioning Thrusters Q

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GPS Block IIR-M

Second Civilian Signal

– More Accuracy – 1.1m

1st Launch 2005
On line in 2010

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GPS Signals: Present and Future

L5 ARNS/RNSS Band L1 ARNS/RNSS Band L2 RNSS Band P(Y ) C/A L2C M L5 L1C

Current GPS

Dual Frequency w/ Semi-codeless P(Y)

Block IIR-M Launch 2005

Dual Frequency L1 C/A & L2C

Block IIF Launch 2007

Three Frequency L1 C/A, L2C, & L5

Block III Launch 2013

L1C, L2C, L5, & L1 C/A Code

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GPS at L1

95
90
85
80
75
70
65
60
55
20
15
10
5

5 10 15 20 Offset from 1575.42 MHz Center Frequency (MHz) Power Spectral Density (dBW/Hz) Relative to 1 Watt L1 C/A L1 P(Y) L1 M L1C

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WAAS - Integrity & Accuracy

Roughly 4x per year a GPS SV Goes “Unhealthy”

–WASS: 6 second alert for unhealthy SV –GPS: 30 minute alert for unhealthy SV via GPS system

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Signal Attenuation - How much?

Forests: Large range (foliage type, humidity, trunks)
Residential houses - up to 30 dB
Commercial buildings: variable, in excess of 40 dB
Non-homogeneous attenuation exacerbate multipath

Transmitter Reflected signal Ņ Attenuated direct signalÓ User Absorbed signal C

r

r e c t R a n g e Path of least resistance

Courtesy of Prof. LaChapelle at U of Calgary

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If the signal is too small to see in 1 msec, we must narrow the receive

bandwidth. Coherent integration is the first choice technique.

#5 High Sensitivity GPS

Adapted from Darius Plausinaitis, Aalborg Univ. dpl@gps.aau.dk

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A-GPS: more useful, more often

Assisted GPS – Ephemeris, Differential Corrections, Time, and Frequency

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Galileo System

Global Navigation Satellite System built by

European Union

– Operational 2008 – The first Galileo test satellite – GIOVE-A was launched on Dec.28, 2005 – First navigation signals were transmitted by GIOVE-A on Jan.12, 2006

Interoperable with GPS
30 satellites in three Medium Earth Orbit MEO

planes at 23,616km above the earth

– 9 satellite + 1 spare per plane – The inclination of the orbits was chosen to ensure good coverage of polar latitudes, which are poorly served by the US GPS system

One revolution 14 hours 4 min

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GNSS Spectrum

L5 E5 E6 L1 E2 E1

1164 MHz 1214 MHz 1260 MHz 1300 MHz 1559 MHz 1587 MHz 1591 MHz 1563 MHz 1215 MHz 1237 MHz

L2

RNSS Bands RNSS Bands ARNS Bands ARNS Bands

1610 MHz

GALILEO Bands (Navigation) GPS Bands (Current & modernized) GLONASS Bands (Current & modernized)

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GPS & Galileo at L1

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Data Collection (SiRF and Stanford)

BOC(1,1) BOC(15,2.5)

Dish allowed us to see Galileo GIOVE-A signal when transmission was initialized
Code not necessary for data capture
Vector Signal Analyzer used to capture data from transmission

GIOVE-A E1-L1-E2

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Galileo First Contact

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GLONASS – Russia

Soviet Era System
2001 – 6 SVs
2005 – 13 SVs
18 SVs by 2008
3 year life – today
7 year life – new
Funding from India

Glonass Receivers use Multiple Frequencies = $$$

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QZSS – Japan

Quasi Zenith Satellite

System

Modification of

Geosynchronous Orbit

Covers Japan and

Southern Asia

WAAS like data on L1,

L2 and L5

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Satellites alone are never enough

Plus parking garages, tunnels, subway systems, etc.

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SiRF InstantFIX™

System Model Overview

SiRF GPS Monitoring Information SiRF Server SGEE Ephemeris Synthesis

' U T T f

xyz r XYZ xyz NS

∇ ⋅ ⋅ =

φλ λ φ

λ φ φ u U r u U r u r U U

r

⋅ ∂ ∂ ⋅ ⋅ + ⋅ ∂ ∂ ⋅ + ⋅ ∂ ∂ = ∇ ' cos 1 ' 1 ' '

[ ] ∑ ∑ ∑

∞ = = ∞ =

⋅ + ⋅ ⋅         ⋅ + ⋅ ⋅         ⋅ − =

1 1 * 1 *

sin cos ) (sin ) (sin '

l l m lm lm lm l e l l l l e

m S m C P r a r J P r a r U λ λ φ µ φ µ

∫

⋅ ⋅ ⋅         ⋅ =

M l l l e l

dm P R a M J ) ' (sin 1

*

φ

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TTFF Comparison

10 20 30 40 50 60 70 80 90 100 TTFF Seconds Open Sky Urban Canyon on Roof Urban Canyon on Dash InstantFix Autonomous

SF Urban Canyon

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1 Day Old Synthetic Ephemeris

Typical San Francisco Run with Extended Ephemeris

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7 Day Old Synthetic Ephemeris