OceanographyLaboratory Name Lab Exercise#2

MARINECHARTS AND NAVIGATION

DEFINITIONS:

Bearing:The directionto a target from your vessel, expressedin degrees, 0OO" clockwise through 360". Bearingcan be expressedas a true bearing (in degreesfrom true, or geographicnorth), a magneticbearing (in degreesfrom magnetic north),or a relativebearing (in degreesfrom ship's head).

Gourse:The directiona ship must travel to arrive at a desireddestination.

Cursor:A cross hairmark on the radarscreen operated by the trackball.The cursor is used to measurea target'srange and bearing,set the guard zone,and plot the movementof other ships.

ElectronicBearing Line (EBLI: A line on the radar screenthat indicates the bearing to a target.

Fix: The charted positionof a vesselor radartarget.

Heading:The directionin which a ship's bow pointsor headsat any instant, expressedin degrees,O0Oo clockwise through 360o,from true or magnetic north. The headingof a ship is alsocalled "ship's head".

Knot: The unit of speedused at sea. lt is equivalentto one nauticalmile perhour.

Latitude:The angulardistance north or south of the equatormeasured from O" at the Equatorto 9Ooat the poles.For most navigationalpurposes, one degree of latitudeis assumedto be equalto 60 nauticalmiles. Thus, one minute of latitude is equalto one nauticalmile.

Longitude:The'angular distance on the earth measuredfrom the Prime Meridian (O') at Greenwich,England east or west through 180'. Every 15 degreesof longitudeeast or west of the PrimeMeridian is equalto one hour's difference from GreenwichMean Time (GMT)or Universal (UT). . Time NauticalMile: The basic unit of distanceat sea, equivalentto 6076 feet, 1.85 kilometers,or 1.15 statutemiles.

Pip:The imageof a targetecho displayedon the radarscreen; also calleda "blip".

(\ PlanPosition Indicator (PPl): The presentation on the displayunit screen which placesyour ship'sposition at the center of the screen.A faint radialline, calledthe "sweep",extends from "o\/n ship's"position to the outeredge of the screen and rotatesin bearingsynchronization with the rotationof the antenna.Around the edgeof the PPIpresentation are bearing indications in b degreeincrements clockwise from 00O".

Range:The distanceto a targetfrom yourvessel ("own ship"),usually expressedin nauticalmiles.

Statute Mile: A unit of distanceused on land, equivalentto 5280 feet, 1.6i kilometers,or .869 nauticalmiles.

Target: An object that reflectsenergy radiated from your radartransmitter; displayedas a pip on the radarscreen.

VariableRange Marker (VRMI:A ring on the radar screenthat can be adjustedto determinethe distanceto a target.A VRM is displayedas a dashedring to distinguishit from the solidfixed rangerings.

MARINECHARTS

You must show all of your calculations to receive futl credit for your answers. circle your final answers or write them in the spaces provided.

1. FortBragg is locatedat 39o26'30"N,123"48'OO"W. San Franciscois locatedat37"4S'30"N, 1222O,20"W. HanaBay, Maui is locatedat2C-.4S'O0"N,15S"59,10"W

a. What is the differencein latitudebetween Fort Braggand San Francisco? ;

b. What is the differencein latitudebetween Fort Braggand Hana Bay?

+\ c. How much farther.northis Fort Braggthan San Francisco?Express your answer in nautical miles and sfafute miles.

d. What is the differencein longitudebetween Fort Braggand San Francisco?

e. What is the time difference(to the nearestminutel between Fort Braggand HanaBay?

2. A powerboat is travelingat 15 statutemiles per hour. What is its speedin knots?

3. Assumethe good ship CR is ciuisingon a courseof 7OoT. was broad a..lf you wished to changecourse when the Pt. CabrilloLighthouse be on your starboard beam, what would the relative bearing to the lighthouse when it was time to changeyour course?

time? b. What would the true bearingbe to the lighthouse at the same

t\ DEAD RECKONINGNAVIGATTON

Use the mercator chart of Portsmouthand southernMaine below to answer the next threequestions.

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RADARNAVIGATION

INTRODUCTION

This exerciseis designedto acquaintyou with some of the basicfunctions and capabilitiesof a radar system. Instructionsin this exerciseshould provide arnple guidanceto allow you to completethis exercise.You may wish to refer to the Operator'sManual for further detailsor instructions.lf you are uncertain of what a particularfunction key is designedto do, or how to proceedin general, askthe instructor for help before proceeding!

BASICOPERATION OF THE FURUNO..FCR1O1O RADAR

1. Use the illustrationon the next pageto familiarizeyourself with the locations and functions of the keys on the controlpanel. Pay particularattention to the use and functions or the keys marked:POWER/OFF; RANGE; TX/OFF; EBL112 OFF;VRM 112 OFF;and FUNCTION.Locate the TRACKBALLwhich controlsthe cursor,EBLs, and VRMs.

2. lf the radar unit is not alreadyturned on, press the POWER/OFFtouchpad to turn on the power. The radarrequires 2 minutesand 30 secondsto warm-up; do not attemptto use the radaruntil the message"ST-BY" (stand-by)appears on the screen.

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flq FURUNOFCR 101O RADAR CONTROL PANEL

A/C RAIN Suppresesrain clutter. A/C SEA Suppresessea clutter caused by waves, GAIN Adjustsreceiver sensitivity. ooo POWER/OFF Turns on and off power to the s)6rem. RANGE Selectsradar range. ffi|ffi.n TVOFF Setsthe radarto transmit or stand-by. HM OFF Temporarilyerasesthe heading mark. ffig@ RING Turns the fixed rangerings on and off. @g@ FTC Suppressesrain clutter. lfiiFil fffi'l (FLor-'l l.r4y.JE&!' Lgrr.J lR Reducesor eliminatesradar inter- ltn t/21lcrr serllvu Inl ference. t_gt_ll-* t rnJ Lgru ECHO Activatesand releasesthe echo stretch STRETCH functiorLwhich stretchesechoes @@@ Iengthwisefor better distinction. SHIFT/NAV Shifs the displayand turns the naviga- tion datadisplay (navigation input re- quired) on and off. ZOOM/BRILL Turns the zoom function on and off and adjuststhe brightnessof the screen. PLOT/DIM Turns on and offthe radar target plot- ting deviceand adjuststhe backlighting of the controlpanel. EBL 1/2 OFF Turns the ElectronicBearing Lines (EBIs) on and off. OFF SET T/R Enablesand disablesthe offsetEBL andalternately selects true and relative bearingreadout. VRM 1/2 OFF Turns the Variable RangeMarkers (VRMs) on dndoff. COLOB Selectscolor of targetechoes, background and plot. GUARD Turns on and offthe guardzone alarm. FUNCTION '. Alternately enablesthe functionsof dual function touchpads. Trackball Controls the orsor,*VRMs andEBIs.

3. After the stand-bymessage appears, press the TX-OFFtouchpad to begin transmission.The displaywill light up and.thePPI heading marker, fixed range markers,cursor, and any target pips will appear.lf you wish to discontinue usingthe radarat any time, pressthe TX-OFFtouchpad and the stand-by messagewill againappear. Placing the radarin stand-byhelps extendthe life of \ - 'the radar.Do not turn the radaroff duringthe lab periodunless the instructor directsyou to do so.

t25 BEARING PLOTTING RANGE RING PLOTTING INTERVAL INTERVAL ELAPSEDTIME Nl-4 cYRoils.o" PLor Eo AUTOMATIC GUARD ALARM TUNING FTC TUNINGBAR ECHO STRETCH HEADINGMARK INTERFERENCE CURSOR REFECTOR EBLI

\\ \-/ EBL2

\* VRMI

VRM2

FUNCTIONINDICATION

Eu vn- zooM t59.30T r 9.05 NM 5.73NM 232.30T L 65.toT 1t.4NM VRM INDICATION VRMl VRM2

4, Take a few momentsto study the displayon the screenand compareit to the illustrationabove. The outermostring on the screen (markedin 5 degree increments)is the bearingscale. The solidradial line at 000o is the heading mark.The headingmark is alwayson the screenand showsown ship's heading.

5. Use your ship's compassto determinethe headingof yourvessel (hereafter referredto as the good ship CF. Write your headingin the space provided.

Heading

6. Orientthe Fort Braggand Noyo anchorageChart (18626)provided so that your headingis directedtoward the bow of the CF, as it appearson the radar screen. Now comparethe landformsillustrated on the chart with the echoesthat appear on the screen. Do the landformson the screen closelyresemble those on the chart?Why do you thinkthis is the case?

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t& * RANGESELECTION

1. The rangeselected automatically determines the fixed rangering intervaland the numberof fixed rangerings. The rangeand ring intervalappear at the top left cornerof the display.The rangeshould be set at 1 .5 nauticalmiles at thistime. At this setting there aresix fixed rangerings which are0.25 N.M. apart.The rangeis changedby pressingthe + or - sign on the RANGEtouchpad.

2. Pressthe * sign on the RANGEtouchpad and changethe range to 3 nautical miles.There are still six fixed rangerings displayed, but their intervalis now 0.5 N.M. Use the + and - signson the RANGEtouchpad to displayeach of the possibleranges from 0.25 to 24 N.M. ln the chart below,fill in the rangering intervaland numberof rangerings for eachof the possibleranges.

RANGE(N.M.) 0.25 0.5 0.75 1.5 3.0 6.0 12 24

RANGERING o.25 0.5 INTERVAL

NUMBEROF RINGS

MEASURINGRANGE

The rangeto a target can be measuredin three ways with the FCR 1O1O:by the fixed rangerings, the cursor,or the VRM. The cursorand the VRM allow the most accuraterange determination.

FIXEDRANGE RINGS

The-fixedrange rings can be usedto get a rough measurbmentof the rangeto a target pip. The radar operatorsimply countsthe number rings between the center of the displayand the target pip. After checkingthe fixed range ring interval,the operatorthen need only judgethe distanceof the echo from the inneredge of the nearestring.

1. Usethe chart providedand locatethe CF and the WhistleBuoy, (labeledRW "NA", Mo (A)) located west of the Noyo Bay, Use a pair of divi.dersand the techniquesyou have alreadylearned to determinethe rangeto the buoy from the Cr?.Write that range in the spaceprovided. Recall that one degreeof latitudeequals 60 NM, one minuteof latitudeequals 1 NM, and one secondof latitudeequals .O166 NM.

Range

t?3 2. Set the rangeof the radarat 1.5 NM. Comparethe echoesdisplayed on the screenwith the landformsillustrated on the chart.Once you have oriented yourselfagain, locate the echo of the buoy on your radardisplay. Ask the instructor for assistanceif you cannot locate the buoy on the screen.

3. Usingthe fixed rangering methoddescribed above, estimate the rangeof the buoy from the CR,and write that rangein the spaceprovided.

Range

CURSOR

1. Now use the cursorto determinethe rangeof the sametarget, the whistle buoy. Usethe trackballto placethe cursorintersection on the inneredge of the center of the target. The rangeto the target appearsat the bottom center of the screen.Write that rangein the spaceprovided.

Range

VARIABLERANGE MARKER(VRM)

RANGETOCUBSOR

VRMlndlcatlon - CMTange

VRM

To use the VRM for range determination,you must first familiarizeyourself with the use of the FurucrtoN touchpad.The FUNCTIoNtouchpad alternately engages the functionof the touchpadswith dualfunctions (SHIFT/NAV, ZOOM/BRILL, EBL 112OFF,OFF SET T/R, and VRM 112OFFI. Each time the touchpad is pressedthe functionindication shifts up or down to show which functionis activated.For example,the functionsof the PLOT/DIMare plotting targets and adjustingthe backlightingfor the control panel.To activatethe plottingfunction, therefore,you would pressthe FUNCTIONtouchpad to set the indicationupward (seethe illustrationon the top of the followingpage).

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FUNCTIONINDICATION

FUNCTION Touchpad

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1. Now use the VRM to determinethe rangeof the whistlebuoy. Pressthe FUNCTIONtouchpad to set the indicationupward. Use the trackballto placethe cursoron the insideedge of the whistle buoy's echo.Press the VRM 112OFF touchpadto displaya VRM (the VRM is the dashedring to distinguishit fromthe fixed rangerings). Each time the touchpadis pressedVRMl or VRM2 is enabledor disabledand an arrowappears for ten secondsnext to the activeVRM's readout. The rangereadout in the lower right cornerof the screenwill display the rangeto your target. Write that rangein the space provided.

Range

2. Note that the rangeto the cursorand the VRM continuouslyvaries with trackball operation.A VRM and its indicationwill not be set untilthere is no VRM operation for at least ten secondsand the arrow disappears.To immediatelyset the VRM readout,press the FUNCTIONtouchpad after operatinga,VRM. After this the cursorcan again be operatedindependently of the VRM.

3. To turn off a VRM(s),enable the OFFfunction fo the VRM 112OFF touchpad using.theFUNCTION touchpad and then pressthe VRM 1/2touchpad. Turnoff the VRM before proceedingto the next exercise.

BEARING

There are two ways to determinethe bearingof a target: by the cursor or by an ElectronicBearing Line (EBL). When usingeither method, bearing errors canbe minimizedif you keepyour target echo in the outer half of the screen by changing the range scale (angulardifferences become more difficultto resolve as a target approachesthe centerof the display).

170 CURSOR

1. Operatethe trackballto placethe cursorintersection on the inner edgeof the centerof the whistle buoy.The bearingto your target will appearat the bottom centerof your screen(see the illustrationbelow). You shouldnote thatthe bearing is followed by an "R" indicatingthat the bearingis RELATIVEto your ship's heading.Write that bearingin the spaceprovided (be certainto includethe"R" indication).

Bearing

CURSOR TABGET EBL

BEARINGOFCURSOR R: RdatfueEearing Fimiffiffins-- T: TruoBearing T:True Badng

EBL

1. Enablethe EBL1/2touchpad using the FUNGTIONtouchpad. Press the EBL 1/z touchpadto displayan EBL(the EBL is the dashedradial line to distinguishit from the headingmarker). Eachtimethe touchpadis pressedEBL1 or EBL2isenabled or disabledand an arrow appearsfor ten secondsnext to the active EBL'sreadout at the bottom left corner of the display.

2. Now, positionthe EBLso it bisectsthe whistle buoy's echo.Write thebearing displayedon the screenin the spaceprovided

Bearing

Note that the bbaringto the cursorcontinuously varies with trackballoperation. An EBLand its indicationwill not be set untilthere is no EBLoperation for at least ten secondsand the arrow disappears.To get an immediateEBL readout, press the FUNCTIONtouchpad after operatingan EBL.

3. To turn off an EBL(s)enable the OFFfunction of the EBL1 12 OFFtouchpad and then press the touchpad. Turn off the EBLbefore proceedingto the next exercise.

t1 DETERMININGTRUE BEARING

As notedearlier, all bearingson this radarare displayedas relativebearings (i.e., in degreesfrom ship's head).To relatethe informationdisplayed on the radarscreen to a nauticalchart, however, it is necessaryto convert relativebearings andyour ship'sheading to true directions(i.e., in degreesfrom true north).

1 . Usethe chart provided,a set of parallelrules, and the techniquesyou have alreadylearned and determinethe TRUEand MAGNETICbearings to the whistle buoy from the CF. Write those bearingsin the space provided.

True Bearing

Magnetic Bearing

2. Onceagain use your ship'scompass to determinethe headingof the CB,Write your headingin the spaceprovided.

Heading

3. In the space provided,write the RELATIVEbearing to the whistle buoy from the Cr1as you determined it usingthe EBL(copy the bearingfrom #2 in the EBL exerciseon the previouspage).

RelativeBearing

4. Useyour ship's headingand the relativebearing to the buoy to determinethe TRUEand MAGNETIC bearings to the buoy.Assume that MagneticNorth is 16o Eastof True North.

True Bearing

MagneticBearing

Shutting Down

DO NOTturn the radar off unlessthe instructordirects you to do so. lf youare instructedto shut down the radar,simply press the POWER/OFFand TX/0FF touchpadssimultaneously.

11?-- 120°E 130°E 140°E 4 5 0 0 40°S 30

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30°S Crust Age Contour (10 Ma) 60°S spreading ridge Table 1.

Map Map/Real Real Measurement Age Isochron Chron Distance Distance Distance Rate Rate Rate Number (Ma) Number (mm) (deg Lat.) (NM) (NM/Ma) (NM/year) (mm/Ma)

Average Rate (mm/yr)