The Navigator - Issue 6: RADAR
Contents
1. The use of radar as a collision avoidance tool is covered in detail in the first feature of our two part series 4 09 For the Royal Institute of Navigation Dr Andy Norris FRIN FNI Published by The Nautical Institute Printed in the UK by Newnorth Print Ltd Kempston Bedford UK If you would like to send us your response comments or ideas about anything in this issue or the next please contact the editor at navigator nautinst org In the last edition of The Navigator we discussed ECDIS For this issue we asked the Nautical Institute s Sea going Correspondence Group for their personal opinions and experiences of radar The responses from officers at all stages of their careers from third mate to Commodore cover a wide range of topics We are always interested in hearing your views on the important topics discussed in this publication If you would like to send us your response comments or ideas please contact the editor Emma Ward at navigator nautinst org or look out for the Linkedin discussion We look forward to hearing from you Join the debate on LinkedIn http www linkedin com groups Nautical Institute 1107227 or follow us on Twitter https twitter com Nauticallnst We are active on Facebook https www facebook com thenauticalinstitute and you can watch our videos on YouTube http www youtube com TheNauticallnstitute You can read a digital version of The Navigator or downl2. is an essential tool for safe navigation and improving situational awareness Its use should be balanced with visual Second Officer Fani Sotiria Provatari talks to The Navigator about her career and the importance of job satisfaction In the second article of the series The Navigator examines the use of radar as a navigational aid Editorial committee Editor Emma Ward Design Phil McAllister A Nautical Institute project sponsored by 6 0 For The Nautical Institute Bridget Hogan Lucy Budd David Patraiko FNI Steven Gosling MNI David Patraiko FNI 4 observation in other words looking out of the window ECDIS and the many other available aids to navigation Radar should however also be appreciated for its independence and reliability Modern radar can be highly sophisticated and in addition to any generic radar training that navigators receive there is a real need for ship specific radar familiarisation as specified in the ISM Code Radar can be your best friend in reduced visibility So learn how to use it effectively how far to trust it and how to balance its use with all the other aids to navigation Most of all the windows We hope this edition of The Navigator inspires you to reflect on the use of the radar and to share these thoughts with your fellow navigators This and all other issues of The Navigator are available for free download from www nautinst org en Publications the navigator
3. www rin org uk 10 The Navigator June 2014 1 Kensington Gore London SW7 2AT Tel 44 0 20 7591 3134 aw The focus has been firmly on radar in this issue of The Navigator Here are 10 key aspects to remember about this vital tool Reliable radar Radar has earned its place as a tried and tested best friend to the navigator due to its reliability and independence from external systems such as QPS 2 ee Two for the price of one The two primary uses of radar are for collision avoidance and for navigation Professional navigators need to know how to use radar effectively for both tasks Know your tools Modern radar has many sophisticated functions and options Navigators need to know how to use these tools their limitations and how to operate without them if need be I ie ae Check check and check again Never take anything seen on radar at face value Always crosscheck either visually look out the window or with an alternative independent system Never assume i Familiarity breeds success Understanding how to use radar requires both training and familiarisation Regardless of how well you may know radars in general when you join a new vessel it is essential to familiarise yourself with specific onboard radar units prior to assuming watch Keeping in tune Automatic tuning can be useful However knowing how and when to use manual tuning should be part of familiarisation T
4. June 2014 Issue no 06 Inspiring professionalism in marine navigators i i m t ps P F i z s _ i E E z J i nhs if ri j j i i Li i F j f F x iF j a a F j a f E J i 4 lt i A d I 2 l i l 1 i b e 4 Eyes in the dark OUZ F The wv Nautical a Q Oo y Institute t lt A free publication by The Nautical Institute in association with the Royal Institute of Navigation For many decades radar has been a good friend of the navigator Radar has been our eyes in the dark and restricted visibility and has allowed us to see if not identify targets that could be navigational hazards or assist us with position fixing It does not depend on the correct operation of external systems such as GPS and that is why we trust it Radar found its way onto merchant ships after the Second World War as an early electronic aid Use of it grew slowly and with caution In the 1960s as radar became more common radar assisted collisions became a reality and for the first time ever equioment specific training and revalidation was introduced by the IMO In more recent decades radar has improved remarkably with enhanced filters for clutter effective auto tuning colour displays and the benefits of new technology radar on S Band For many navigators however the true value lies in the fact that oros and cons of radar WATCH OUT WHO S NAVIGATING WAY POINT chang
5. cerned POSITIONING For decades radar has been a tremendously reliable tool for ascertaining the range and bearing of fixed and floating objects The variable range marker VRM and electronic bearing line EBL facilitate a quick and easy check of the vessel s position in coastal waters By simply Thiz VARIA3LIz RANG OF QUICK AN MARK 2ONIC 3EARING LINE EBL FACILITATE A D EASY CHECK OF T Z VESSEL S NAVIGATION corrective action At anchor a true vector set at 60 minutes or more could provide an early indication of dragging OFFSET VRMS AND EBLS In addition to providing a range and bearing from the vessel s own position EBLs and VRMS can be offset carried or dropped elsewhere onscreen to provide a course to make good and a distance to go to a pre determined position This is extremely useful when approaching an anchorage or waypoint or determining a course to steer when for example the vessel makes a planned departure from track The carried EBL also serves as a parallel index line if required and can provide an indication of an object s bearing further along the ship s course which can then be visually confirmed PARALLEL INDEXING The use of parallel indexing to monitor cross track distance is key to navigation On modern radar sets four or more index lines are typically available often in different colours enabling the navigator to index present and future courses Paralle
6. d ways of managing radar for collision avoidance Radar can help with collision avoidance in many ways The simplest perhaps is to lay an electronic bearing line EBL across a suspected target to see if the relative bearing is steady and if a risk of collision exists RELIABILITY While relative bearings vectors are highly reliable and accurate true vectors or decision support tools that rely on inputs such as speed position or gyro data could be inaccurate if the input data is compromised Interpreting radar returns is still an art and not an exact science In other words assume nothing and always try to check visually or by an alternative independent system It is crucially important to routinely change ranges when detecting and monitoring targets Use of the longer range settings gives good prior awareness of more distant but relatively large targets whereas shorter range settings are necessary to detect and discriminate virtually all targets closer to own vessel The use of offsets is also encouraged According to one member of the SGCG operating with centre offset to maximise look ahead is always preferred for both navigation and collision avoidance radars TUNING Radars have options for automatic tuning of gain STC sea clutter FTC rain clutter and AFC tuning control However the automatic settings of these controls will not necessarily give the best performance in all conditions and so manual ad
7. dexing and relative trails for track monitoring and control gt True vectors to indicate the vessel s ground track in steady state conditions gt ARPA also known as target tracking to acquire fixed objects to ground stabilise echo referencing gt Offset EBL and VRM to provide a leading line course to steer distance to go etc June 2014 The Navigator 7 In this series we take a look at maritime accident reports and the lessons that can be learned Fogging up the view inadequate radar use Causes chaos What happened The departure of a bulk carrier was delayed due to thick fog When conditions improved slightly the vessel set off but crossed the river quicker than anticipated The pilot did not monitor the speed and was not familiar enough with the onboard radar equipment to use it correctly He and the bridge crew soon lost situational awareness in the fog and did not carry out a continuous radar watch as per the guidelines The vessel collided with some moored barges before grounding in shallow water Damage was Caused to the hull and shell plating that took two weeks to repair gt Lack of situation awareness lt The issues gt Unfamiliarity with the onboard radar system gt Ineffective use of radar gt Poor bridge resource management Why did it happen Investigations into the incident found that the loss of situational awareness of the bulk carrier s bridge team was instr
8. e if you have one One reader per issue will win an ipad mini as a thank you odie ies per ee MTN oe ee ee a abe em Bo fa fom ead foe art an aed a 3 iay irasi f Terms and conditions apply see www nautinst org thenavigator
9. ed over the years TAKE 10 Nautical Institute WST 77 AG 2 9 Z z AES www rin org uk 2 The Navigator June 2014 52 ial Members of the wider marine community debate the Accident report Fog and unfamiliarity with the onboard radar caused a bulk carrier to ground in shallow water Dr Andy Norris of the Royal Institute of Navigation looks back at the history of radar to find out what s Ten key points to remember about radar 202 Lambeth Road London SE1 7LQ UK Tel 44 0 20 7928 1351 Fax 44 0 20 7401 2817 navigator nautinst org www nautinst org With support from 1 Kensington Gore London SW7 2AT UK Tel 44 0 20 7591 3134 Fax 44 0 20 7591 3131 Director of Projects The Nautical Institute radar is largely autonomous and ship centric So many of our current navigation aids GPS GNSS Loran AIS etc are reliant on external sources that can be interrupted intentionally or unintentionally Yet radar is trusted as the pulse is generated by the ship for the ship and has proved to be highly reliable Modern radar returns very accurate images of targets and can be enhanced with many additional tools such as trial manoeuvres AIS chart overlay underlay and the tried and tested ARPA A comprehensive understanding of the functionality and reliability of radar and these enhancements is therefore essential for navigators This issue of The Navigator is dedicated to radar and its onboard use Radar
10. ements updated by the International Maritime Organization in 2004 only really differ with regards to how information has to be shown to the user taking advantage of the advances in modern digital processing and display technologies In general the basic requirements for target detection performance have hardly changed at all although some useful enhancements have been made to the accuracy of the system Today s user courses for marine radar spend a lot of time on the performance limitations of radar and rightly so One key point is that targets can become invisible when conditions at sea deteriorate due to the effects of sea and precipitation clutter The statutory range requirements for marine radar are labelled as in the clear detection ranges IMO does not specify the allowable degradation in adverse conditions However it does insist that the performance degradation for certain defined rain and sea state conditions is mentioned in the equipment s user manual Taking degradation for granted in this way seems to be totally at odds with what navigators need After all when visual conditions deteriorate the instinct is to rely more and more on the radar While technology has always aimed to lessen Requirement 1946 Latest IMO requirements 2004 standards 2 miles 2 NM X band 1 NM S band 3 4 NM X band 3 0 NM S band these effects as much as possible the potential for significant further imp
11. head up mode whereas North up gives easy association with paper charts or electronic Charts in North up mode These choices may also be affected by the area the ship is in such as pilotage waters or open ocean and should always be coordinated with all members of the bridge team As one experienced pilot advises learn how to use a head up unstabilised display so that if when all the secondary inputs fail you still have a useful tool MODE OF DISPLAY Radar and AIS data can only be used safely if there is a good understanding of both true and relative motion Poor understanding can result in a major collision Displayed vectors RADAR COLLISION AVOIDANCE on radar tracked targets and AlS acquired targets can be set to be either true or relative Again the combination of settings and uses will depend on the individual circumstances One mate suggested that for collision avoidance the use of relative vectors and true trails is most useful Radar and AIS data can be very effective if used together either manually or automatically association Benefits and weaknesses of operating radar and AIS together include gt wo independent ways of detecting targets gt wo independent estimates of a target s range bearing course and speed gt Radar detection of targets that do not carry AIS gt Clear AIS transmissions almost unaffected by clutter gt AIS can be seen whereas radar detec
12. help readily show direction but not so long as to be confused with the ship s heading marker Training and familiarisation Trial manoeuvres are both useful and used a real lifesaver A lot of self teaching goes on and some radar displays are more user friendly than others If an unfamiliar user wants to find say a simple tool and has to search down through a number of menu layers to access it on a dark night on an unfamiliar vessel this can present its own hazards June 2014 The Navigator 3 RADAR COLLISION AVOIDANCE COMISION COUTSe There are two clear and distinct purposes for which radar is used navigation and collision avoidance While there are some fundamentals of radar use that are the same for both tasks the ideal radar set up for the two tasks is quite different In fact if there are two radars available it may well be advisable to use one radar for long range and one for close range detection or one for navigation and one for collision avoidance 00 O0 o Q though there are clear best practices on setting up a radar for collision avoidance purposes the tools you use nd the way you manage the display can be based on personal preference or local conditions For example the situation can be very different if you are in a crowded waterway from when a vessel is on the open sea Here members of The Nautical Institute s Seagoing Correspondence Group SGCG offer advice on their own preferre
13. justment can be important Professional navigators must ensure that they are proficient with the use of these controls and be familiar with them for every ship they sail on Poor manual tuning is a real hazard as is failure to recalibrate the radar when conditions change Best practice is to always check the settings of all controls before assuming a watch TWO RADARS BETTER THAN ONE Using one radar for navigation and the other for collision avoidance is best in some circumstances while in others it may be beneficial to use one radar for greater range and the other for close range detection It is important too to recognise the difference between S Band 3GHz 10cm and X Band 9GHz 3cm radars both of which are required on larger vessels S Band is generally preferable in adverse conditions such as fog rain and heavy seas while X Band is noted for good angular discrimination required in pilotage waters for example On ships where the radar displays can be inter changed such as on Integrated Bridge System workstations it is essential to know which radar system S or X you are using at any time and the expected performance parameters for each DISPLAY ORIENTATION Shipboard radar displays can be configured in a range of orientation modes head up North up course up each offering benefits and hazards Head up display allows easy association with views from the bridge windows or from electronic charts in
14. l indexing allows an almost instant reaction to any unplanned deviation from course as well as continuous monitoring of the vessel s R VRM AND POSITION IN COASTAL WATERS extending the VRM and rotating the EBL to a number of conspicuous points on the radar picture and laying off those range and bearing lines to the corresponding charted objects the navigator can quickly establish the ship s position This applies to both paper and electronic charts However it is important to note that any position plotted is historical a record of where the vessel once was It provides no indication of where the vessel is likely to be Only by creating an estimated position EP using the ship s course and speed will a future position become clear On ground stabilised settings the true vector or predictor provides a real time EP The vector length can be adjusted from a few seconds typically up to 60 minutes or more When sailing in shallow waters or close to land this predictor can provide early warning of deviation and prompt early progress in relation to its track The great advantage of parallel indexing is that it requires nothing more than the relative track of a fixed object parallel and reciprocal to the vessel s own track Remember the saying to safely get by use your PI IN SUMMARY Radar offers the navigator many useful functions for pilotage and coastal navigation gt Parallel in
15. lenges for bridge officers in the future Bridge officers must prove their knowledge and competence on a daily basis There is intense competition especially among women to make it in a profession dominated by men Where do you see your career going from here do have high hopes even though building a career at sea is particularly difficult for women given the predominantly male environment at every tier would like to pursue further training as appropriate to potentially help me take my career ashore working either for a shipping company or for the Coast Guard June 2014 The Navigator 9 Royal Institute of Navigation Science Technology Practice Dr Andy Norris FRIN FNI Reassessing radar then now and in the future Dr Andy Norris an active Fellow of The Nautical Institute and the Royal Institute of Navigation looks back at the history of radar and wonders how much it has really changed over the years Back in 1946 the first requirements for civil marine radar were laid out to manufacturers during an international meeting on radio aids to marine navigation Since then it is remarkable how many of the basic performance requirements for radar have really not changed as the table to the right shows The 1946 performance requirements matched not only what was technically feasible at the time but also what would provide highly useful information for the marine navigator The latest requir
16. oad it in PDF format at www nautinst org thenavigator some thoughts on CE CEECEE Verification Never take anything seen on a radar screen at face value Always crosscheck either visually or with an alternative independent system Never assume Collision avoidance On vessels fitted with two radars would advise that one should be dedicated to navigation and the other to collision avoidance Tracking too many targets can mentally overload the navigator in high traffic areas Only targets of interest need to be acquired and tracked Navigation Radar returns are not an exact match for charted features and errors are frequently not quantifiable Everyone needs to practise use radar along with visual lookout as the primary method for navigating our district consider ECS AIS etc as supplementary aids Identifying targets Utilizing target trails of suitable length looking at wake with relative vectors looking ahead provides the best visual information about a target It s great to be able to plop a plot on anything and see how the target compares when it pops up on the ECDIS screen Brilliant Using vectors When the accent is put on navigation then it is important to have a true relative motion and true vectors True vectors with a proper set of time length could render quick and adequate information regarding the ship motion with regard to shore and shore fixed hazards A vector should be short enough to
17. p the radar North up head up and course up A North up display is often preferred as the orientation of the radar picture will match that of a paper chart and so also matches most peoples mind set of an area In head up mode the up direction of the display represents the vessel s heading in course up mode it represents the direction which has been input as the vessel s desired course In normal use all three modes make use of the ship s gyro compass to reference the display which is known as azimuth stabilisation However if the gyro compass becomes inaccurate or unavailable the radar will have to be set to the head up unstabilised mode This could cause the smearing of land and other echoes with alterations of course MOTION MODE Two motion modes are provided True and Relative In True Motion the displayed position of own ship moves at a scaled speed across the display that corresponds to the vessel s actual motion In Relative Motion mode the displayed position of own ship is static When off centred this provides maximum lookout ahead as well as possible early warning of rain showers squalls landmarks wheel over points and of course traffic STABILISATION MODE There are two stabilisation modes ground and sea Ground stabilisation means that the display is referenced to the seabed by GNSS or through a twin axis Doppler log For sea stabilisation the display is referenced to the sea current
18. rovement has been somewhat ignored in recent years Military precision Basic concepts for further improvements were developed many years ago by the military in order to be able to see such things as submarine periscopes It was realised that if the Soe pU MAJ received signal could be ERTE aT precisely compared to the actually transmitted signal in both amplitude and phase then the effects of clutter could be reduced by a factor of hundreds or even thousands Today s implementations of so called coherent radars using modern semiconductor devices can make a very sophisticated system much more affordable even for the commercial market CFP l FETTE EYATEONKNY AUTI Yes Unfortunately the current IMO requirements for radar do not promote significant moves in this direction In some ways we still have a 1940 s mindset of what radar can and cannot do for us As with all onboard equipment users of radar should be encouraged to express their own thoughts if they see a need to improve performance Physics and affordability obviously get in the way of creating the perfect product However when advances are possible we should do all we can to meet users needs Although such radars are more expensive to buy than standard systems they are more likely to reduce accidents and improve navigational efficiency therefore representing valuable cost savings financial and otherwise Contact RIN at
19. that own ship is experiencing typically based on SDME measurements It is generally accepted that the ground stabilised mode is more useful for normal navigation especially when combined with setting tracked targets to show their True vectors However since set and drift affect heading and aspect ground stabilised displays should be used with caution where target tracking is concerned Having a predicted ground track in confined waters is especially useful particularly where visual information and cues are limited or unavailable such as in fog With ground stabilised radar all stopped targets will show the set and drift which is ideal for navigation in channelled waters with significant tidal streams However the effects of current will vary across the observed area TARGET TRAILS Target trails can be set to be either True or Relative whatever motion mode the display is set to In coastal and confined waters navigators often select Relative Motion True Trails RMTT as it provides the illusion of true motion while retaining the advantages of relative motion With ground stabilised radar all stopped targets will show the set and drift which is ideal for navigation in channelled waters with significant tidal streams However the effects of current will vary across the observed area Since set and drift affect heading and aspect ground stabilised displays should be used with caution where target tracking is con
20. their motivations careers to date and thoughts for the future In this issue Second Officer Fani Sotiria Provatari discusses the challenges facing women at sea and reveals what for her are the greatest rewards of the navigator s profession What triggered your interest in building a How do you feel during a navigational watch professional career at sea l keeping shift on the bridge From a young age always had a passion for There is oressure and a lot of responsibility that traveling and had hoped that would some day makes it imperative to do my job properly feel have the chance to explore the entire world This satisfied especially when my supervisors are happy career path albeit demanding and a tough slog with me and the way perform my duties while certainly has given me this opportunity keeping watch What do you consider as the most important reward of your work onboard To be recognised as being good at what do and to have my worth appreciated by others To gain new knowledge and experiences How did you end up in your current position began as an apprentice onboard a passenger ship While one of the more stimulating aspects of my position was the interaction had with passengers it was the seamless communication and effective teamwork between the other crew members and myself that spurred me on to continue in this career In your opinion what are the greatest chal
21. tion can be impossible e g behind islands and headlands gt Radar doesn t have to rely on external data sources unlike AIS gt AIS can indicate changes in course and speed quicker than radar can detect them gt AIS can often provide more information about a target INFORMATION OVERLOAD Information overload is a serious danger Modern radars can display a wide range of additional information and symbols but too much information can lead to confusion and non detection of targets Such additional information can come from ARPA AIS vectors and vector lengths target names and information guard zones exclusion zones Chart information etc As the shipping industry migrates towards greater use of Integrated Bridge Systems IBS Integrated Navigation Systems INS and eNavigation the need to manage portrayed information will become ever more essential Never forget that it is easier to detect targets on a relatively clear display Further information about using radar for collision avoidance can be found in the Nautical Institute s guidebook Radar and AIS by Dr Andy Norris June 2014 The Navigator 5 N NAVIGATION ile Fine radal prior to arri ival or departure will need to 55 of dec sions A which of the radar s features and modes of display 6 The Navigator June 2014 ORIENTATION MODE There are three orientation modes the navigator may choose from when setting u
22. umental to the grounding along with their lack of Knowledge about how to use the onboard radar equipment The pilot s attempt to establish the vessel s position and speed using the radar was unsuccessful as he was not familiar with the set Inappropriate settings on the radar meant it would have been difficult to identify the vessel s position due to clutter In addition the roles and responsibilities of the bridge team had not been confirmed before the vessel left its berth despite the tricky conditions caused by the thick fog As a result no one was instructed to keep a continuous radar watch and the course and speed of the bulk carrier were not monitored closely enough during the manoeuvre The bulk carrier quickly ran into trouble and the fog caused the team to lose situational awareness meaning that the erroneous course was not corrected nor the alarm raised in time What changes have been made gt Recommendations were made to improve bridge team performance 9 especially when operating in conditions of poor or restricted visibility gt Advice was issued to pilots to take care when setting up a radar with which they may be unfamiliar gt Restricted visibility berthing and unberthing exercises were added to simulator training sessions 8 The Navigator A man s world How one woman Is successfully building a career at sea In this series The Navigator speaks to current navigational personnel about
23. uning functions should be checked before assuming each watch EER PA N Target practice Continually monitor different ranges and consider the use of screen offsets in order to detect all possible targets Be band aware Know the difference between S and X Band radars Know which is being displayed and know how to use each strategically to best effect Team talk Mentoring there is not usually one best way to set preferences for a radar display and the choice of display options changes with navigational circumstances Discussing these options amongst the bridge team and Pilot can provide an excellent learning experience for all navigators young and old Be alert to advancements Radar technology and performance are advancing Be alert to these new systems and encourage their application onboard where financially justified June 2014 The Navigator 11 AA Fa eww Kia matii aaee wordwide and 1s a i R i resource for the industry J _ Ine role of the navigator A Passage pianning _ Positioning _ ECDIS Inya SUE bred ee use Org and 1olow we IAs oy 3 GON and win an ipad mini We want to see as many people as possible reading The Navigator Just post a picture of you with your Navigator on ns faa Twitter including the hashtag NAVsnap or tag us In your post on Facebook www facebook com thenauticalinstitute and tell us the name of your ship or your colleg
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