SUCCESS STORYHigh Accuracy Survey under Bridges
The vessel «Spreegrund», property of WSA Berlin, has been equipped by MacArtney Germany with state-ofthe-art equipment including the Apogee-E, the highest accuracy inertial navigation system from SBG. One of
the main goals was to obtain very good results when surveying under bridges.

The catamaran survey vessel named«Spreegrund» serves as survey vessel
on German lakes, adjacent canals, andrivers (Berlin, Brandenburg, Eberswalde,and Lauenburg). It carries out complete
surveys at speeds of up to 6 knots andwater depths down to 20 meters.

STATE-OF-THE-ART
HYDROGRAPHIC EQUIPMENTCLIENT

WSA Berlin
APPLICATION

Hydrography/Charting
PRODUCT

Apogee-E Inertial Navigation
SystemPROJECT

Multibeam echo sounderstabilization and data
georeferencing

The onboard equipment features thefirst Teledyne RESON T20-P TripleHead
multibeam echo sounder providing anexcellent swath coverage even in very
shallow water environments such as
rivers and canals. This set up allows users
to survey large areas in a short time.
Additional sensors include a Teledyne
ODOM CV 100 single beam echo sounder,a Teledyne RDI Navigator DVL and aValeport SWiFT as well as a Valeport Ultra

SV sound velocity sensor. Besides this,the SBG Apogee-E inertial navigation
system has been supplied together with
two ObeLx-R GNSS heading receivers(Septentrio boards inside) which enable
good position acquisition even under poor
GNSS environments, e.g. under bridges.
The ObeLx-R receivers, manufactured
by MacArtney Germany, and the DVL
are connected to the inertial navigation
system to get stable position data. Thedata acquisition software QINSy storesand visualises all information.
The onboard control system andsoftware work to ensure optimal dataacquisition from the survey sensor suite.
It is capable of handling enormous data
stream of up to 25,000 soundings persecond.

« We needed the highest accuracy INS to maintain the highprecision of the rest of the advanced equipment »Alexander Schmidt, Technical Sales Manager at MacArtney Germany

SUCCESS STORY - Charting under bridges
CHARTING UNDER BRIDGES WITH THE APOGEE INS
Surveying under bridges is a challenging application that fully
requires the fusion between inertial and GNSS data. Indeed,GNSS receivers are perturbed when vessels are crossing bridges
and may cause outages or incorrect data. In the case of WSA
Berlin, this is a day-to-day challenge, explaining why MacArtney
chose an Apogee-E inertial navigation system connected with
their own Dual-antenna GNSS receiver (Septentrio inside). “We
needed the highest accuracy INS to maintain the very highprecision of the overall equipment,” states Alexander Schmidt
from MacArtney Germany.

Google Map

COMBINATION OF INERTIAL, GNSS, AND DVL DATA
The Apogee-E is the highest accuracy inertial navigation systemfrom SBG. It provides outstanding roll, pitch and heave data andis the only INS of its category to fuse in real-time inertial datawith an external DVL and two GNSS receivers. Data are fused togenerate outputs for motion compensation and georeferencing.
“ DVL input in the Apogee-E is a big advantage. It helps for realtime GNSS outages, especially under bridges.” adds Alexander.
When GNSS outages occur, the Apogee-E is able to maintainthe position in real-time. Its performance is even better when
aided by a DVL. The INS integrates velocity data to the internalalgorithm to reduce the inner drift of the IMU . “We obtainedexcellent results with the Apogee-E, the images speak forthemselves” to conclude Alexander Schmidt, Technical SalesManager .

Overlapling: 95% Confidence

AUTHOR
Hélène LEPLOMB from SBG Systems
September 2017

Alexander Schmidt

Seafloor

ABOUT MACARTNEY GERMANY

APOGEE-E KEY FEATURES» 0.008° Roll & Pitch» Up to 0.025° GNSS Heading using two antennas» 5 cm Heave, 2.5 cm Delayed Heave» Post-processing» Compact andcost-effective solution» GNSS & DVL aided

MacArtney Germany – MacArtney Group is a sales andconsulting company for marine and underwater technology.
We focus on the sales, integration, training and serviceof oceanographic, hydrographic and geophysical sensors
and systems. Further, MacArtney Germany has its own
calibration and maintenance facility for oceanographic
instrumentation.
MacArtney Germany is a competent partner for alltechnical measurements in the deep ocean, the coastal
zone, estuaries as well as rivers and lakes.
MORE INFO: https://www.macartney.dewww.sbg-systems.com

SBG Systems EMEA (Headquarters)
Phone: +33 1 80 88 45 00
E-mail: sales@sbg-systems.com

SBG Systems North America
Phone: +1 (657) 845-1771
E-mail: sales.usa@sbg-systems.com

V1.1 April 2018 – September 2017 – All rights reserved © 2017 SBG Systems“DVL input in the Apogee-E is a big benefit. It helps forreal-time GNSS outages, especially under bridges.”