Maritime GPS Promotion Organization, Japan

Maritime RTK-GNSSPositioning System

Maritime GPS Promotion Organization, JapanThree-P Nihombashi Building, 4-1-13 Nihonbashi Honcho, Chuo-ku, Tokyo 103-0023, Japan
Phone: +81-3-6631-7940 Facsimile: +81-3-6631-7941
URL: https://www.mar-gps.or.jp/E-mail: kikou@mar-gps.or.jp2024

In recent years, GNSS positioning using satellites such as GPS, QZSS, GLONASS, etc.
has become an essential technology for port construction.
The Maritime GPS Promotion Organization (GPS Organization) is a non-profit
organization established by the government and private sectors to promote thewidespread use of maritime GNSS positioning systems developed for port construction.
We provide highly accurate and stable real-time kinematic positioning (RTK - GNSS)
services by radio transmission of GNSS positioning correction information fromreference stations located throughout Japan.

Reference station

Vibrating rollers

Bulldozers
Unloading barge

Construction material carrier
Floating crane

Survey ship
Seabed improvement pontoon

Dredger

Image of the use of the maritime RTK-GNSS positioning system

Maritime GNSS Positioning System

Real-time Kinematic Positioning
By installing a reference station at a known point behind the construction area andtransmitting GNSS positioning correction information obtained at the reference station toa mobile station as a positioning point (unknown point), highly accurate real-time
kinematic positioning (RTK- GNSS) is possible even for mobile objects.
Real-time kinematic positioning (RTK- GNSS) is the most accurate (positioning accuracy
is about 2cm horizontally and vertically) and most stable positioning method, so it isused as standard in port construction.

GNSS satellite 2

GNSS satellite1

GNSS antenna

GNSS satellite 3GNSS satellite 4

GNSS satellite 5

Correction datatransmitting antenna
Correction datareceiving antenna

Remote surveillance system

GNSS antenna

Data receiver
Monitor antenna

Reference station(known point)

GNSS receiver

Remote surveillancestation
InternetMobile station(unknown point)

User sideOrganization side

1

Construction management
computer system

This is a service of the GPS Organization.

Static Positioning

Stand-alone positioning
Differential Positioning(DGNSS)

GNSS positioning

Relative positioning

Kinematic positioning

Stand-alone positioning

Interference Positioning

Real-time kinematic positioning

Precise Point Positioning(PPP)(RTK-GNSS)

Network RTK positioning
Transmits correction
information

GNSS positioning method

Mobile station

Reference station

Relative positioning

The maritime GNSS positioning system of the GPS Organization is characterized by its
high stability, with no radio wave blockage or interference over a wide area, by means ofassigning a dedicated frequency band and high-power radio waves.
The system also eliminates the need for users to set up their own reference stations foreach construction project, which is expected to improve the productivity of port
construction.
No needfor a private reference station

Highly reliable systemSince a dedicated frequency band is secured and correction informationis transmitted at high power, there is no risk of radio wave blockage orinterference and the system is extremely stable. Positioning information
at the reference station is remotely monitored via the Internet.

There is no need for the construction workers to set up andmanage the private reference station for surveying. Therefore,
the efficiency of the positioning work can be improved.

High-precision positioning

Centralized information management

Highly accurate positioning of about 2 cm horizontally and verticallyis possible. Furthermore, the positioning-control area can becovered up to 20 to 30 km away from the reference station since
positioning information is transmitted by high-power radio waves.

One reference station enables centralized information
management even for a large project that operates work vesselsof various types at a time.

Equipment configuration of the Maritime RTK-GNSS positioning system

Advantages of using the Maritime RTK-GNSS positioning system

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History of the GPS Organization

Location & service areas of reference stations

Since 1995, when the Maritime GPS Promotion Organization started providing GPS correction
information in the Kobe and Kanmon areas, we have built up a record of achievements in many
maritime construction projects.
These include port development, reclamation, ground improvement, construction of offshore airports,etc., all of which are large-scale projects that represent Japan.
We support these projects by maximizing the use of real-time kinematic GNSS, which provides precise
surveying accuracy.

GPS Reference Stations established by the Maritime GPS Promotion Organization are located invarious locations to provide highly accurate correction information services.
In areas where there is no reference station, a simplified reference station will be set up at the request ofthe user to provide services.

1993

Inauguration of the “GPS Technical Committee” in September 1993
Research group for real-time kinematic GPS positioning system developedby the Fourth Port Construction Bureau of the Ministry of Transport, etc.

January 1995 RTK-GPS reference station information broadcasting
begins in the Hanshin area.
Establishment of a reference station at Kobe Portopia Hotelfor the purpose of earthquake reconstruction in the Hanshin area.
Port Island, Rokko Island GPS surveying.

Minami-Honmoku Port
development (Yokohama Port)

March 1995 Started RTK-GPS reference station information broadcastingin the Kanmon area.

1996

RTK mode

Service area

G P S : approx. 15-20 km radius
GNSS : approx. 30 km radius

Positioning horizontal
accuracy±(1cm+2ppm·D)±(2cm+2ppm·D)

Information hours

24 hours throughout the year

Data format

RTCM-SC104

6 Kannonzaki Reference Station

9,600bps

7 Nagashima Reference Station

GPSGNSS

9 Kobe Reference Station

GPSGNSS

10 Osaka Reference StationGPS

14 Kanmon Reference StationGPS

15 Hakata Reference StationGPS

16 Hachinohe Reference StationGPS

17 Kanda Reference Station

GPS

18 Onahama Reference StationGPS

19 Naha Reference Station

GPS

22 Chiba Reference Station

GPSvaries depending
on environmental conditions(varies by model)

February 1994 Inaugurationof the “Council for the Advancement of Marine Surveying Technology”.

1995

Positioning method

vertical1 Niigata Reference Station(14,400 bps for bidirectional communication)

Transmission frequency

229MHz band

Data update interval

1 second

16

The New Offshore Disposal
Site development (Tokyo Port)

November 1996 General meetingto establish the “Maritime DGPS Utilization Promotion Council”.

1

1998 Establishment of Hakata and Irago reference stations.
Establishment of Kansai International Airport reference station
for second phase construction of Kansai International Airport

23 2 2245 6Kansai International Airport(2nd phase Offshore airport)

91415 17

4 Kawasaki Reference StationGPS

5 Yokohama Reference StationGPS

71018

GNSSGNSS

23 Yokohama Reference StationGNSSGNSS(Daikoku)

GPSGNSS

24

Central Japan International Airport

Service areas of reference stations
Kyushu Area

Tokyo Bay Area
Edo River

14 Kanmon Reference Station

19Shimonoseki
Port of Shimonoseki
Port of KokuraaRer

FukuokaMinato CityTamaRrHaneda Airport

Ichihara

eriv
R
doYo

Kobe

Amagasaki
Osaka

Kobe airport

Hanshin Port

Sakai
Takaishi

Kiso River
Nagara River

10 Osaka Reference Station

Port of Yokohama

22 Chiba Reference StationSodegaura
Port of Kisarazu

5 Yokohama Reference Station(Minami-honmoku)

7 Nagashima Reference Station
Itami Airport

Kinuura Port No.3 Landfill development(Aichi Prefecture)

Naha Airport Runway Expansion Project

Port of Chiba

Fukuoka Airport

Ise Bay Area

9 Kobe Reference Station

March 2023 Establishment of Tanegashima Reference Station

Chiba

4 Kawasaki Reference Station

15 Hakata Reference Station

Osaka Bay Area

March 2018 Establishment of Kinuura Reference Station

Narashino

ive

Yokohama

June 2016 Establishment of the Hitachinaka Reference Station

Koto CityrRiv

Port of Kanda

17 Kanda Reference Station

Port of Hakata

Haneda Re-expansion Runway DiveKitakyushu Airport

gaFebruary 2014 Establishment of Naha Reference StationawKitakyushu

OnFukutsu
Koga

2 Aomi Reference StationakAr

Tokyo Bay Mouth Passage development(Tokyo Bay)

August 2010 Establishment of Onahama Reference station

To date since 1993

GPS

24 Tanegashima Reference StationApril 2007 Haneda Reference Station operation begins
for construction of Tokyo International Airport’s Runway D.

2023

2 Aomi Reference Station(Missing numbers are the discontinued stations)

August 2005 General meeting for the establishment of a non-profit organization,“Maritime GPS Promotion Organization”.

December 2009 Establishmentof Hachinohe and Kanda Reference StationGNSS(Minami-honmoku)

Data transmission speed

2000 Establishment of Naoetsu, Kannonzaki and Aomi reference stations.
Establishment of Tokoname reference station for Chubu International Airport

2005

C om mo n referen ce stati o n s

Yokosuka

Nagoya23 Yokohama Reference Station(Daikoku)

Aisai
YatomiKuwanaTokai
Chita
Port of Nagaya
Yokkaichi
port of yokkaichi
TokonameCentral Japan
International Airport

6 Kannonzaki Reference StationHanda
Port of Kinuura

Kansai International Airport

The GPS reference station can cover the measurement range of approximately 15 to 20km radius by RTK-GPS. (Indication in the map is 15km radius.)
The GNSS reference station can covers the measurement range of approximately 30km radius by RTK-GNSS. (Indication in the map is 30km radius.)

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Wide Range of Applications
for the RTK- GNSS Positioning System
The RTK-GNSS positioning system has been applied to various offshore construction and maintenance
operations, as well as three-dimensional (3-D) surveys. The heights of underwater structures and theuneven depth of the seafloor are now more accurately profiled in addition to positioning-control of thework vessels at the sea surface conducted so far. Consequently, the RTK-GNSS positioning system has
provided high reliability for various offshore construction projects.

Government-owned work vessel
The government-owned work vessels have employed highly-reliable RTK-GNSS positioning system andcarried out dredging work and surveying.
Survey ship

Drag suction dredger

Kaisyo maru

Port construction

owned by Ministry of Land, Infrastructure,
Transport and Tourism

Dredging

Depth sounding

Hakuzanowned by Ministry of Land, Infrastructure,
Transport and Tourism

Ground improvement

Kaien

owned by Ministry of Land, Infrastructure,
Transport and Tourism

Seiryu maruowned by Ministry of Land, Infrastructure,
Transport and Tourism

Kairyuowned by Tokyo Metropolitan Government Bureauof Port and Harbor

Diverse Utilization

3-D survey of the seafloor using
multi-beam sonar equipment has
been greatly improved by the use ofRTK-GNSS.

The cutter-head or grab-bucket of adredger can accurately target thedredging line to avoid excess work withmanagement by RTK-GNSS.

Work vessels performing ground-improvement
and pile-driving operations can achieve
accurate control of the positions and bearing
angles with the use of RTK-GNSS.

Rubble leveling

Caisson installation

Reclamation

OffshoreWind Power Construction

Determination of quay deformation
earthquakes

Automatic berthing
and unberthing of vessels

The highly-reliable RTK-GNSS positioning
technology is now utilized in theconstruction of offshore wind farms being
deployed over the country.

RTK-GNSS positioning technology isapplied to measure post-earthquake quay
deformation and assist in determining
whether or not the quay can be used.

The drag suction dredger “KAISHOMARU” is equipped with an automatic
berthing and unberthing system using
RTK-GPS positioning technology.

Offshore wind power generation facilityin the United Kingdom

Demonstration testat Port of Kawasaki

GPS Organization Service Activities
Rubble placement and leveling on theseafloor can be achieved rapidly with theassistance of RTK-GNSS.

Accurate positioning of caisson installation
work has been ensured by RTK-GNSS
devices attached to the caisson.

Offshore reclamation with earth and sandhas been unloaded and placed from abarge accurately using RTK-GNSS.

Ground subsidence survey

Land leveling

Operationof the reference stations
We will provide services of maritime
positioning GNSS systems to users
and contribute to the efficiency ofport construction and other projects.

Ground subsidence survey
systems combined with
RTK-GNSS and laser leveller
have achieved highly accurate
vertical measurements duringmoving and continuous operation.

Land-leveling work is now carried out with vibrationrollers and other heavy vehicles by confirming theposition and height by RTK-GNSS.

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Research and study,
Application and promotion,and Human resource development
for GNSS positioning technology
We w i l l p r o m o t e t h e s p r e a d o f
RTK-GNSS positioning technology
throughout Japan and the training ofengineers through workshops andlectures.

GPS wave metermonitoring, etc.
We will contribute to wave survey
and tsunami disaster prevention
through monitoring of GPS ocean
wave meters deployed by theMinistry of Land, Infrastructure,
Transport and Tourism in variousregions.

Admission Guide

Our Organization is based on the membership system. For use of our GNSS reference stations, please apply for membership in advance.
Photo credits. Okinawa General Bureau, Cabinet Office; Ministry of Land, Infrastructure, Transport and Tourism / Kanto Regional Development Bureau, Chubu Regional Development Bureau,
Hokuriku Regional Development Bureau, Kyushu Regional Development Bureau; Bureau of Port and Harbor, Tokyo Metropolitan Government; Port and Harbor Bureau, Port of Yokohama,
Aichi seaside Environment Center; The Port and Harbor Association of Japan; Kansai International Airport Land CO., Ltd.; Central Japan International Airport Company, Limited;
Goyo Construction Co, Ltd., TOA Corporation, TOYO CONSTRUCTION CO., LTD, WAKACHIKU CONSTRUCTION Co., Ltd, The Haneda D-runway Construction Project66