iXBlue GAPS Guide

GAPS Maintenance
Arm / Hydrophone Replacement and Calibration
User Guide

GAPSMaintenance -User Guide
Revision History
Edition Date Comments
A 09/2018 Creation
B 11/2019 iXblue Multilogger, calibration validation criteria 1
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Copyright
All rights reserved. No part of this manual may be reproduced or transmitted, in any form or by
any means, whether electronic, printed manual or otherwise, including but not limited to
photocopying, recording or information storage and retrieval systems, for any purpose without
prior written permission of iXblue.
Disclaimer
iXblue specifically disclaims all warranties, either expressed or implied, included but not
limited to implied warranties of merchantability and fitness for a particular purpose with
respect to this product and documentation. iXblue reserves the right to revise or make
changes or improvement to this product or documentation at any time without notify any
person of such revision or improvements.
In no event shall iXblue be liable for any consequential or incidental damages, including but not
limited to loss of business profits or any commercial damages, arising out of the use of this
product.
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Warranty
iXblue provides a standard warranty of one (1) year covering this product against any defect in
materials or manufacture. The warranty starts from the date of shipment of the product from
iXblue’s manufacturing premises to customer’s location and its duration is indicated in the
certificate of warranty delivered with the product. In the event that a defect in materials or
manufacture becomes obvious during the stipulated warranty period, iXblue will undertake, at
its sole discretion, either to repair the defective product, bearing the cost of all parts and labor,
or to replace it with an identical product.
In order to avail itself of this warranty, Customer must notify iXblue of the defect before expiry
of the warranty period and take all steps necessary to enable iXblue to proceed. Customer
shall be responsible for the packaging and the shipment of the defective product to the repair
center notified by iXblue, the cost of such shipment being borne by Customer. iXblue agrees
to bear the cost of return freight, based on CPT (Cost Paid To) Customer’s airport location,
import tax-free.
This warranty shall not be construed as covering defects, malfunctions or damages caused by
improper use or inadequate maintenance of the product. Under no circumstances shall iXblue
be due to provide repair or replacement under this warranty in order a) to repair damage caused
by work done by any person not representing iXblue for the installation, repair or maintenance
of the product ; b) to repair damage caused by improper use or connection to incompatible
equipment, and specifically, the opening of the housing of the equipment under warranty shall
cause the warranty to be automatically canceled ; c) to maintain any product that has been
modified or integrated into a larger configuration, if such modification or integration increases
the duration or difficulty of the maintenance of said product.
This warranty covers the product hereunder and is provided by iXblue in place of all and any
other warranty whether expressed or implied. iXblue does not guarantee the suitability of the
product under warranty for sale or any specific use. iXblue’s liability is limited to the repair or
replacement of defective products, this being the sole remedy open to Customer in the event
the warranty becomes applicable. iXblue cannot be held liable for indirect, special, subsequent
or consequential damage, irrespective of whether iXblue has or has not received prior
notification of the risk of occurrence of such damage.
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Export Regulation
iXblue products and services shall not be exported or re-exported in the following countries
(including their territorial waters): Cuba, Iraq, Iran, North Korea, Sudan and Syria.
The following export control guidelines shall apply as related to French rules and regulations.
Dual-use goods This product or service belongs to the dual-use goods category, it has not been specifically
developed for military applications but may be used in the scope of either civilian or military
applications. It is then concerned by the dispositions of Regulation (EC) N° 428/2009 of the
Council of 5th May 2009 as modified, directly applicable in French law.
As a consequence, this product or service is subject to the following dual-use goods export
control procedures from France:
●It can be freely delivered to France or any country within EU.
●It can be exported under iXblue’s Union General Export Authorization n° EU001 to the
following countries (so called “bona fide”): Australia, Canada, USA, Japan, New-
Zealand, Norway and Switzerland / Liechtenstein.
●It can be exported to other countries but only through the preliminary issuance of an
individual export license by the French authorities.
If an individual export license has to be issued by the French authorities, it is required that you
provide a description of your usual activity (and the one of the end-user if different) and that the
end-user fills in an end-user certificate (using a predefined format). This certificate includes the
description and location of the intended application for the product or service as well as a
commitment not to re-export the said product or service without the preliminary agreement of
the French authorities.
Once the product or service has been delivered to its first destination, the following rules
apply:
●From an EU country member, the good is free of movement as long as it remains within
EU.
●From an EU country member, the good can only be re-exported to a non EU country
member under the dual-use goods export control procedures set forth by the local national
authorities.
●From a “bona fide” country, the good can only be re-exported under the dual-use goods
export control procedures set forth by the local national authorities.
●From another country, the good can only be re-exported under both the conditions of the
original export license from France (depending on its type and content) and the dual-use
goods export control procedures set forth by the local national authorities.
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GAPSMaintenance -User Guide
Guide Overview
This user guide is the maintenance guide for GAPS. It is mainly focused on the replacement of
a damaged arm and or faulty hydrophone from the GAPSunit by a new one. The user guide
must be read and understood prior to performing the specific maintenance tasks described in
it. The manufacturer shall in no case be held liable for any application or use that does not
comply with the stipulations in this user guide. This user guide applies to GAPS III and IV.
●Part 1: Replacing an Arm
This part contains a procedure that explains how to take off one arm from a GAPS unit and to
fasten a new arm at the same place. Extracting the hydrophone from the arm is not
recommended.End user may buy a complete kit (arm and hydro).
●Part 2: Calibrating the GAPS unit
This part contains a procedure that explains how to calibrate the GAPS unit. The calibration is
necessary after replacing a faulty arm and or hydrophone by a new one.
●Appendix: Replacing an Hydrophone
This part contains a procedure that details the removal of an hydrophone from an arm and its
replacement by a new hydrophone. This procedure is for expert users only.
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Abbreviations and Acronyms
GAPS Global Acoustic Positioning System
GPS Global Positioning System
INS Inertial Navigation System
RTK Real Time Kinematic
SNR Signal to Noise Ratio
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Text Usage
Bold Bold text is used for items you must select or click in the software. It is
also used for the field names used into the dialog box
Courier
Text in this font denotes text or characters that you should enter from the
keyboard, the proper names of disk drives, paths, directories, programs,
functions, filenames and extensions
Italic Italic text is the result of an action in the procedures. It is also used for ref-
erencing to other document titles
Icons
The Note icon indicates that the following information is of particular interest
and should be read with care.
Important
The Important mention indicates that the following information should be read
to forbid or prevent a product dysfunction or a faulty operation of the equip-
ment.
The Caution icon indicates that the following information should be read to for-
bid or prevent product damage.
The Warning icon indicates that possible injury or death could result from fail-
ure to follow the provided recommendation.
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Table of Contents
1 REPLACING AN ARM 11
1.1 DISMANTLING 11
1.2 REASSEMBLING 13
1.3 CALIBRATION AFTER ARM REPLACEMENT 16
2 CALIBRATING GAPS 17
2.1 PURPOSE OF THE CALIBRATION 17
2.2 USBLCAL DESCRIPTION 18
2.2.1 Installing USBLCal 18
2.2.2 Overview of USBLCal 18
2.2.3 Parameters 19
2.3 CALIBRATION PROCEDURE 20
2.3.1 Mooring Structure 20
2.3.2 Procedure 21
2.3.3 Validating a Calibration 26
IXBLUE CONTACT - SUPPORT 27
IXBLUE CONTACT - SALES 27
APPENDICES 28
A REMOVING THE HYDROPHONE 28
B INSERTING THE HYDROPHONE IN THE ARM 29
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1 Replacing an Arm
1.1 Dismantling
The following procedure explains how to remove one arm from the GAPS antenna. The
required tool is a metric Allen key size 4.
1. Set up the GAPS antenna upside down.
2. Use the Allen key to unscrew the three socket head cap screws CHC M5-12 that fasten the
arm to the antenna body.
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3. Start removing the arm by translating it gently along its own axis until you have access to the
connector of the hydrophone to the GAPS housing.
4. Alternately, gently and progressively unscrew and pull on the connector of the hydrophone to
the GAPS housing in order to disconnect the connector.
You have now removed the arm of GAPS from the GAPS main body.
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1.2 Reassembling
The required tools are:
●Three CHC M5-12 screws
●Sandpaper 220
●Metric Allen key 4
●Glue (e.g. Bostik 1400)
1. Clean and rub with sandpaper the titanium insert of the male part of the connector. Check that
the electrical pins are shiny. Contact iXblue if the pins are corroded (not shiny).
2. Grease the two terminations of the connector.
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3. Spread some glue on the thread of the three screws.
4. Make sure to install the arm at the correct location on the GAPS housing. Make sure to have
the same labels on both items.
5. Perform the screwing manually, do not use any tool. Alternately push and screw the
connector to its plug until the pins of the male connector are fully inserted in the female plug.
Check via the small hole in the connector that the junction is fully achieved. Once the
connection is completed, do not press any more because you may damage the connector.
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6. Insert the whole cable inside the arm and install the arm in its final location. Insert the three
screws and tighten them with a torque of 3 N.m. The screws are made of titanium and should
not be tightened too hard. Start tightening the two screws on the outside and finish by the
screw on the inside of the GAPS housing.
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GAPSMaintenance -User Guide
1.3 Calibration after Arm Replacement
Calibrating your GAPSunit (section 2) after replacing an arm (section 1) is recommended in
order to avoid introducing a bias in the positioning. However, the positioning repeatability of
GAPSis preserved. See on figures below the amount of bias that may be introduced if no
calibration is performed after the replacement of a faulty arm.
Figure 1 - Bias introduced vs. GAPSaccuracy
Figure 2 - Average bias vs. slant range for a SNR_IN of 10 dB
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2 Calibrating GAPS
2.1 Purpose of the Calibration
Why The purposes of the calibration are:
●Estimation of the exact antenna geometry, including:
>Misalignments between INS and hydrophones (heading, roll & pitch)
>Relative positions of hydrophones (Δx, Δy and Δz)
●Verification of the accuracy (for the considered Signal to Noise Ratio)
When GAPS system is calibrated by iXblue a very first time and then a calibration is needed each
time a defective hydrophone or defective arm is removed for exchange with a new one.
How You need to operate the complete positioning system and its external sensors:
●Vessel with deployement system for the GAPS antenna
●Complete mooring line (buoyancy, lest, acoustic release)
●GAPScompatible transponder
●GAPS (with cable, GAPS BOX and PC)
●Differential or RTK GPS
●A sound velocity probe
The calibration procedure involves maneuvering the vessel to perform an “8-shape” navigation
pattern around the stationary transponder. While doing this, you compute the position of the
transponder “seen” from every possible angle. The USBLCal software processes the data
input in the system and computes nine parameters that characterize the misalignments a,nd
relative positions of hydrophones. These coordinates are displayed under the form of a 3x3
array.
After the input into the system of the coordinates of the hydrophones that were computed
during the first navigation, a second “eight” navigation pattern allows their validation.
Criteria ●Two consecutive calibrations must provide same antenna geometry (within 0.5 mm)
●The SNR variation between hydrophones is less than 5 dB
●The obtained positioning precision for the beacon must be within the specification
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2.2 USBLCal Description
2.2.1 INSTALLING USBLCAL
The USBLCal software is to be found on the delivered CDROM. Installation starts
automatically as soon as the CD is placed in the CD-drive of the user workstation. USBLCal
requires the operating system Windows Seven or 10.
Make sure that you uninstall any previous version of USBLCal before installing the new one.
2.2.2 OVERVIEW OF USBLCAL
USBLCal calculates the nine calibration parameters to be uploaded into GAPS through a
configuration file. The main window shown below is made of the areas:
●File: opening of data files, choice of the language and display of the current file
●Processing: selection of transponder, radius, response level, antenna type)
●Display: display of ship, raw, selected and calibrated positions
●Quality: gives a percentage of rejection, NSR and global precision of the calibration
●Calibrated antenna: calculation and display of calibration offsets
Figure 3 - Main window of USBLCal application
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2.2.3 PARAMETERS
The parameters of USBLCal application are:
File
Multiple Files Check box to activate when the input file is made of several
small files.
File Count In case of multiple files, the number of files.
English Language of the application can be French or English.
Processing
Transponder All the available transponders are displayed in a drop list.
Position Count Total number of positions detected for the transponder.
Selection Radius Radius of a circle selecting all valid positions inside the
circle and rejecting positions outside the circle.
Selected Count Transponder positions inside the circle of selection radius.
Response Level Response level of the transponder.
Antenna Type Type of antenna of the USBLsystem tracking the
transponder.
Display
Ship Positions Check box displaying the navigation of the ship when
active.
Selected Positions Check box displaying the positions of the transponder
inside the selection radius when active.
Raw Positions Check box displaying all the original positions of the
transponder when active.
Calibrated Positions Check box displaying the positions of the after when active.
Quality
Rejection Percentage of the amount of rejected positions with respect
to the amount of raw positions. Acceptable rejection < 25%.
SNR Max min signal to Noise Ratio. Acceptable SNR < 5 dB.
Precision
Precision is based on the CEP50 radius that includes 50%
of the positions:
H 1/2 2/3 3/4
Delta X, Y, Z in mm
Vectors difference in distance between the distances
between hydrophones.
Angle Heading Roll Pitch Angular offsets.
Calibrated
Antenna
H 1/2 2/3 3/4 in mm
X, Y, Z Distances between hydrophones in the calibrated antenna.
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2.3 Calibration Procedure
Calibration consists of the following steps:
●Deploying the transponder on a mooring: see section 2.3.1
●Procedure: see section 2.3.2
>Sailing the first 8-shape navigation pattern and data acquisition
>Loading data in USBLCal and computing the offsets that must be residual
>Entering the offsets into the Web-based user interface
>Sailing a second 8-shape navigation pattern and acquiring data
>Loading data in USBLCal and re-computing the offsets that must be very small (same
magnitude order than the accuracy of the heading and vertical reference unit)
2.3.1 MOORING STRUCTURE
Figure 4 - Mooring structure
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