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The International Marine Contractors Association 
(IMCA)  is  the  international  trade  association 

representing  offshore,  marine  and  underwater 

engineering companies. 
 

IMCA  promotes  improvements  in  quality,  health,  safety, 
environmental and technical standards through the publication of 

information  notes,  codes  of  practice  and  by  other  appropriate 
means. 
 

Members  are  self-regulating  through  the  adoption  of  IMCA 
guidelines  as  appropriate.    They  commit  to  act  as  responsible 

members by following relevant guidelines and being willing to be 
audited against compliance with them by their clients. 
 

There are two core activities that relate to all members: 

 

Competence & Training 

 

Safety, Environment & Legislation 

 
The Association is organised through four distinct divisions, each 
covering  a  specific  area  of  members’  interests:  Diving,  Marine, 

Offshore Survey, Remote Systems & ROV. 
 

There  are  also  five  regional  sections  which  facilitate  work  on 
issues  affecting  members  in  their  local  geographic  area  – 
Asia-Pacific, Central & North America, Europe & Africa, Middle 

East & India and South America. 
 

IMCA 

M 229

 

 

This report has been prepared in order to give IMCA members 
an overview and review of the Mini RadaScan position reference 
sensor  as  used  within  dynamic  positioning  applications.  
Mini  RadaScan  is  a  microwave  radar  sensor  system  which  has 

gained wide usage within marine offshore operations. 
 

The  major  part  of  the  document  has  been  prepared  by  the 
manufacturers of this system, Guidance Marine Ltd.  It covers the 
components  of  the  system,  sensor  design,  operation  including 

advantages  and  disadvantages,  servicing  and  maintenance, 
applications and technical specification. 

 

 

www.imca-int.com/

marine 

 

 

The information contained herein is given for guidance only and endeavours to  

reflect best industry practice.  For the avoidance of doubt no legal liability shall  

attach to any guidance and/or recommendation and/or statement herein contained. 

© 2015 IMCA – International Marine Contractors Association

 

 

Summary of Contents for Mini RadaScan

Page 1: ...Mini RadaScan Microwave Radar Sensor for Dynamic Positioning Operations IMCA M 229 October 2015...

Page 2: ...onal sections which facilitate work on issues affecting members in their local geographic area Asia Pacific Central North America Europe Africa Middle East India and South America IMCA M 229 This repo...

Page 3: ...3 Responders 11 8 Operation 13 8 1 Dashboard 13 8 2 Multiple Sensor Multiple Target Operation 14 8 3 Mini RadaScan Interoperability and Compatibility 14 9 Servicing and Maintenance 16 9 1 Software Upg...

Page 4: ......

Page 5: ...sophisticated as technology has allowed Within the relative position measurement equipment range the DP market is familiar with the use of laser and microwave sensors 4 5 6 7 This document describes...

Page 6: ...ors Association IMO International Maritime Organization IP Internet protocol LAN Local area network LED Light emitting diode mrad milli radians OSV Offshore supply vessel PCI Peripheral component inte...

Page 7: ...itions where the presence of heavy fog heavy rain snow dust or steam could affect the performance of laser systems A typical vessel will utilise a number of sensors simultaneously Therefore each senso...

Page 8: ...rol the sensor using the dashboard software System components are shown in Figure 1 Figure 1 Mini RadaScan system components Mini RadaScan Responders one or more that are mounted on the fixed platform...

Page 9: ...ications such as drilling rigs and production platforms Multi targets tracking provides target range and bearing measurements and is also capable of calculating vessel heading It is mainly used in mob...

Page 10: ...nsor Placement Sensor placement varies with each application therefore the information hereafter is provided as a general guideline On a platform supply vessel PSV the typical mounting position for th...

Page 11: ...ne should be configured in the Dashboard software Following these guidelines should prevent the sensor detecting any ghost reflections from metallic surfaces which may occur from any microwave based s...

Page 12: ...y VFD mounting holes and pressure vent I O for the DP system and the dashboard The radar dome is attached to the base by fixing screws while the gasket ensures a tight seal The assembly and disassembl...

Page 13: ...of light Figure 5 FMCW beat frequency illustration no Doppler shift While DP operations are usually executed at low speed the vessel movements are still significant enough to introduce a non negligib...

Page 14: ...gnal generated by the transceiver is sampled and processed so that the energy peak can accurately be measured by a sample position i Figure 7 which is then converted to a bearing measurement using the...

Page 15: ...tracking using the dashboard interface Once a responder has been detected motion tracking is achieved using both range and bearing predictor algorithms These predictors are used to optimise the obser...

Page 16: ...range of DP operations it is strongly recommended to follow the installation procedure see section 6 3 to optimise the signal quality and achieve the maximum range specified 7 3 2 Power Source The sy...

Page 17: ...d or a touch screen display During normal operation the sensor updates the dashboard scanner display Figure 10 Figure 10 Mini RadaScan dashboard When a target has been detected the display shows the r...

Page 18: ...ly Figure 11 Figure 11 Multi responder multi sensor operation As illustrated in Figure 11 a DP operator can track more than one responder at the same time whilst another DP operator can track one or m...

Page 19: ...esponder right When using multiple targets because of the differing modulation types certain rules must be adhered to A comprehensive guide to the differences between these targets is available 10 10...

Page 20: ...dashboard can be upgraded in the field using a USB memory stick or by transferring release files on the local network e g marine computer The two step procedure involves Remote installation of the se...

Page 21: ...rine applications Figure 13 the smaller footprint and mounting requirements of the Mini RadaScan has expanded the range of applications to smaller vessels Figure 13 Suitable vessel applications Platfo...

Page 22: ...e they must be shielded from one another with a metal screen The screen must be large enough to physically shield the Mini RadaScan sensor from the whole width of the X band antenna The Mini RadaScan...

Page 23: ...rror in the tangential direction Radial error is more or less constant over a wide operating range For a given bearing error tangential position error is proportional to the distance from the sensor t...

Page 24: ...s below a threshold the measurement is suppressed and the fix is not supplied to the DP system This threshold is set so that measurements cut out before the errors grow much above the level seen at hi...

Page 25: ...ncy Various mitigating measures are taken within Mini RadaScan but it remains the fact that operation in this range is the most challenging in terms of range accuracy And in this range sea reflection...

Page 26: ...e 19 Accuracy scatter plot Standard deviation 0 230 m Figure 20 Accuracy scatter plot Standard deviation 2 06 mrad Both range and bearing errors are quite a lot larger than in the most normal operatin...

Page 27: ...Frequent Small Errors Table 1 Sea reflection accuracy summary 11 4 2 Sea Reflection Typical Operating Conditions Here are some range and bearing measurements typical of station keeping operations in t...

Page 28: ...t less than 125 m and 1 accuracy of 0 1 m in range and 1 mrad in bearing are commonly achieved 11 5 Frequently Asked Questions 1 Does Mini RadaScan operate on the same principles as X band radars No A...

Page 29: ...nstallation 8 What type of DP systems can Mini RadaScan be connected to The Mini RadaScan was designed specifically as a generic DP position reference sensor It supports all the major DP systems and i...

Page 30: ...w and fog It was also noted that although the unit has a number of moving parts this has caused no issues over a prolonged period of years Members have stated that the need to set up a target responde...

Page 31: ...60 x 132 x 71 mm Weight 12 2 Sensor Specifications Sensor Technical Details Sensor type FMCW Emission frequency 9 2 9 3 GHz Maximum output power 1 W Operating range 10 m to 600 m Range accuracy 0 25 m...

Page 32: ...ective 2004 108 EC EMC CE Certified FCC Approved 12 3 Responder Specifications Responder Technical details Emission frequency 9 2 9 3 GHz Power 220V 110V mains adapter Rechargeable battery 30 days Non...

Page 33: ...ave radar sensor for dynamic positioning operations 7 IMCA M 224 Guidance on RADius relative positioning system 8 IMCA M 199 Guidelines on installation and maintenance of DGNSS based positioning syste...

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