Inte

rnationalSym

posi

um

on

GPS/G

NSS

2008,

11-1

4N

ovem

ber

2008

Tokyo

Univ

ers

ity

of

Marine

Sci

ence

and

Tech

nolo

gy

Tom

oji

TAKASU

and

Akio

YASU

DA

�Back

gro

und

�Eva

luate

dPerf

orm

ance

�Ante

nnas

and

Rece

ivers

Configura

tion

of

Experim

ent

2

�Configura

tion

of

Experim

ent

�Eva

luation

Meth

ods

�Resu

lts

of

Experim

ent

�Concl

usi

ons

�cm

-levelacc

ura

cyof

posi

tion

with

RTK-G

PS

�Expensi

ve

(>$9,0

00)

geodetic-

gra

de

dual-

frequency

ante

nnas/

rece

ivers

are

nece

ssary

�Still

not

popula

rbeca

use

of

its

cost

issu

e

3

Sim

ple

Quest

ions

�W

hat

isth

ediffe

rence

betw

een

low

-cost

(<$300)

(sin

gle

-fre

quency

)ante

nna/r

ece

ivers

and

geodetic-

gra

de

dual-fr

equency

ante

nnas/

rece

ivers

?

�W

ith

low

-cost

ante

nnas/

rece

ivers

,RTK-G

PS

can

not

pro

vid

epra

ctic

alperf

orm

ance

?

�Raw

ante

nna/r

ece

iver

perf

orm

ance

�Ante

nna

phase

cente

rst

abili

ty

�Carr

ier-

phase

multip

ath

Code

multip

ath

4

�Code

multip

ath

�RTK-G

PS

perf

orm

ance

�Posi

tionin

gacc

ura

cy(R

MS

err

ors

)

�Ratio

of

corr

ect

AR

(am

big

uity

reso

lution)

�TTFF

(tim

eto

firs

tfix)

with

AR

�Various

ante

nna/r

ece

iver

com

bin

ations

Low

-cost

u-b

lox

AN

N-M

S$31

Aero

Ante

nna

AT575

$200

AntC

om

AG

15A2-X

S-3

$194

5

AntC

om

AG

15A2-X

S-3

$194

Mic

roPlu

s2335TB

$47

Pio

neer

GPS-M

1ZZ

Ant

?

Trim

ble

Bulle

tII

I$125

Geodetic-

gra

de

(for

refe

rence

)

NovAte

lG

PS-7

02-G

G$995

Low

-cost

u-b

lox

AEK-4

T$179

*1

u-b

lox

EVK-5

H*2

$99

*1

6

Geodetic-

gra

de

(for

refe

rence

)

NovAte

lO

EM

V-3

$7,

995

NovAte

lSupers

tar

II$165

Hem

isphere

Cre

scent

$285

*1

module

only

,*2

F/W

vers

ion

3.0

0

Targ

et

Ante

nna

GPS S

ate

llite

7

Refe

rence

Rece

iver

(Dual-fr

eq)

Targ

et

Rece

iver

PC (

Data

Logger)

Refe

rence

Ante

nna

(Dual-fr

eq)

Ante

nna

Mount

with G

round P

lane

20cm

Φ

Appro

x. 1 m

�Raw

ante

nna/r

ece

iver

perf

orm

ance

�Continuousl

yca

ptu

res

raw

obse

rvation

data

at

the

targ

et

and

refe

rence

(24hr)

�Fie

ld-c

alib

ration

analy

sis

by

AN

TTO

OL

v.1.1

8

�Fie

ld-c

alib

ration

analy

sis

by

AN

TTO

OL

v.1.1

�RTK-G

PS

perf

orm

ance

�Pro

cess

es

raw

obse

rvation

data

with

RTK-G

PS

alg

orith

ms

by

RTKLIB

v.2.1

.0

�In

teger

am

big

uity

isre

solv

ed

by

LAM

BD

Aand

valid

ate

dby

ratio-t

est

(thre

shold

=3)

�Eva

luate

sTTFF

with

AR

by

slid

ing

start

tim

e

�Analy

sis

toolw

ritt

en

as

MATLA

Bm

-file

s

�Funct

ions:

�In

puts

RIN

EX

OBS/N

AV

of

targ

et/

refe

rence

Dete

rmin

es

ante

nna

phase

cente

rposi

tion

and

9

�D

ete

rmin

es

ante

nna

phase

cente

rposi

tion

and

variation

by

field

calib

ration

meth

od

�Est

imate

sco

de

and

carr

ier-

phase

multip

ath

�Analy

zes

rece

iver

SN

R(C

/N0)

�G

enera

tes

plo

tsof

analy

sis

resu

lts

�Fre

ely

ava

ilable

under

GPLv

3lic

ense

Exam

ple

sof

Analy

sis

Resu

lts

10

Ante

nna

PCV

Carr

ier-

phase

Multip

ath

Code

Multip

ath

11

RTK-G

PS

Posi

tionin

gAcc

ura

cyRTK-G

PS

TTFF

with

AR

12

Low

-cost

Ante

nna/R

ece

iver

(AN

N-M

S/A

EK-4

T)

Geodetic-

gra

de

Ante

nna/R

ece

iver

(GPS-7

02-G

G/O

EM

V-3

)

13

-3cm

+3cm

-3cm

+3cm

Low

-cost

Ante

nna/R

ece

iver

(AN

N-M

S/A

EK-4

T)

Geodetic-

gra

de

Ante

nna/R

ece

iver

(GPS-7

02-G

G/O

EM

V-3

)

14

Ele

vation

Angle

(deg)

Ele

vation

Angle

(deg)

090

90

0

1cm

1cm

RM

S=

0.3

2cm

RM

S=

0.4

4cm

Low

-cost

Ante

nna/R

ece

iver

(AN

N-M

S/A

EK-4

T)

Geodetic-

gra

de

Ante

nna/R

ece

iver

(GPS-7

02-G

G/O

EM

V-3

)

15

Ele

vation

Angle

(deg)

Ele

vation

Angle

(deg)

090

90

0

1m

1m

RM

S=

0.2

2m

RM

S=

0.7

5m

0.4

0.6

0.81

Carr

ier-

phase

Multip

ath

(RM

S,cm

)0.4

0.6

0.81

Ante

nnas

*1

Rece

ivers

*2

16

0

0.2

0.4

0.6

0.81

ANN-MS

AT575

4G15A2-XS-3

2335TB

GPS-M1ZZ Ant

Bullet III

GPS-702-GG

0

0.2

Code

Multip

ath

(RM

S,m

)

0

0.2

0.4

0.6

0.81

AEK-4T

EVK-5H

SuperStar II

Crescent

OEMV-3

0

0.2

*1

with

rece

iver

OEM

V-3

*2

with

ante

nna

GPS-7

02

Low

-cost

Ante

nna/R

ece

iver

(AN

N-M

S/A

EK-4

T)

Geodetic-

gra

de

Ante

nna/R

ece

iver

(GPS-7

02-G

G/O

EM

V-3

)

EW

EW

17

RM

SErr

or

(cm

):E

0.3

9,N

0.5

9,U

1.0

8Fix

ing-r

atio:

98.7

%

RM

SErr

or

(cm

):E

0.2

6,N

0.3

6,U

0.7

7Fix

ing-r

atio:

99.8

%Fix

Flo

at

10cm

10cm

NS

UD

NS

UD

Low

-cost

Ante

nna/R

ece

iver

(AN

N-M

S/A

EK-4

T)

Geodetic-

gra

de

Ante

nna/R

ece

iver

(L1/L

2)

(GPS-7

02-G

G/O

EM

V-3

)

18

TTFF

(sec)

01800

TTFF

(sec)

01800

Mean:

652.8

s95%

:1840.0

sM

ax:

3490.0

s

Mean:

0.5

s95%

:0.0

sM

ax:

130.0

s

�Low

-cost

ante

nna/r

ece

iver

�Ante

nna

has

poore

rch

ara

cterist

ics

esp

eci

ally

on

code

multip

ath

than

geodetic-

gra

de.The

sele

ctio

nis

import

ant.

19

sele

ctio

nis

import

ant.

�Rece

iver

has

no

larg

edegra

dation

conce

rnin

gsi

gnaltr

ack

ing.

�RTK-G

PS

with

low

-cost

ante

nna/r

ece

iver

isfe

asi

ble

ingood

conditio

n.

�TTFF

has

larg

ediffe

rence

betw

een

single

and

dual-fr

equency

.W

eneed

more

sate

llite

s.