THE BASICS OF PLOTING
OCEAN LOCATIONS
the GPSLATITUDE &LONGITUDE
Robert Perry
DISCLAIMER:
The images, maps and diagrams inthis presentation were taken from
the public domain on the world wide web. This slide show is for non-
commercial, educational purposesONLY !
e-mail: zalophus@UCLA.edu
LATITUDE & LONGITUDE LINES:
LATITUDELines go eastand west.
LONGITUDELines go northand south.
Map: http://worldatlas.com/aatlas/imageg.htm
a GLOBAL POSITIONINGSATELLITE RECEIVER isused to measure and recordthe LATITUDE andLONGITUDE of aLOCATION in DEGREES,and MINUTES.
LATITUDE
LONGITUDE
latitude34O 06.54’ N
Degrees
Minutes
North ofequator
Ground Tracks for the27 Global Positioning Satellites (effective 9/28/98)
At least 4 GPSatellites must be locked in to giveLatitude, Longitude, Elevation and GPS Time.
X Y Z & T
SAMPLE ACTIVITY:
PLOT THE POSITIONS OF A FEWLOCATIONS ON A CHART
Materials needed for this sample activity:
Copies of Santa Monica Bayor southern California chart
pencils
Ruler or straight-edge
Location data(from GPS)
STEPS TO FOLLOW IN THIS ACTIVITY:
1- FIND THE LATITUDE LINE ANDDRAW IT IN PLACE USING YOURPENCIL AND RULER.
2- FIND THE LONGITUDE LINE ANDDRAW IT IN PLACE USING YOURPENCIL AND RULER
3. PLACE AN “X” TO MARK THE SPOT WHERE LATITUDE AND LONGITUDE LINES CROSS.
WHAT DOES THE NAUTICAL CHART TELL YOU ?
1. LOCATION OF LAND AND LANDMARKS.
2. LOCATION OF OCEAN AND DEPTHS.
2. LOCATION OF OCEAN AND DEPTHS.
DEPTHS ARESHOWN
BY DARKERCOLORS
3. DEGREES OF LATITUDE (horizontal lines).
3. DEGREES OF LATITUDE (horizontal lines).
DEGREES ofLATITUDE
GET BIGGERGOING NORTH
4. DEGREES OF LONGITUDE (vertical lines).
4. DEGREES OF LONGITUDE (vertical lines).
DEGREES ofLONGITUDEGET BIGGERGOING WEST
NOTICE THAT THE GRIDLINES ON THIS CHART AREEQUAL TO 5’ (minutes) EACH.
SAMPLE PROBLEM #1:LOCATE THE SANTA MONICA PIER
GIVEN: THE SANTA MONICA PIER IS LOCATED AT34O 00.50’N and 118O 29.10’W
GIVEN: THE SANTA MONICA PIER IS LOCATED AT34O 00.50’N and 118O 29.10’W
First, we’lldraw the
LATITUDELINE
using yourruler and a
pencil.
GIVEN: THE SANTA MONICA PIER IS LOCATED AT34O 00.50’N and 118O 29.10’W
34O 00.50’N(green line)is just a tinybit North of34O 00.00’N
GIVEN: THE SANTA MONICA PIER IS LOCATED AT34O 00.50’N and 118O 29.10’W
34O 00.50’N[our location is
someplace alongthis green line]
GIVEN: THE SANTA MONICA PIER IS LOCATED AT34O 00.50’N and 118O 29.10’W
Next, let’sdraw the
LONGITUDELINE
using yourruler and a
pencil.
GIVEN: THE SANTA MONICA PIER IS LOCATED AT34O 00.50’N and 118O 29.10’W
118O 29.10’W(yellow line)is just a tiny
bit before118O 30.00’W
GIVEN: THE SANTA MONICA PIER IS LOCATED AT34O 00.50’N and 118O 29.10’W
The SantaMonica Pier
is located wherethe two lines
cross each other.
GIVEN: THE SANTA MONICA PIER IS LOCATED AT34O 00.50’N and 118O 29.10’W
“X” marksthe spot !
X
SAMPLE PROBLEM #2:LOCATE THE MANHATTAN BEACH PIER
X
GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT33O 53.00’N and 118O 24.90’W
X
GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT33O 53.00’N and 118O 24.90’W
33O 53.00’ is between 33O 50’
and 33O 55’
X
GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT33O 53.00’N and 118O 24.90’W
X
GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT33O 53.00’N and 118O 24.90’W
X
GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT33O 53.00’N and 118O 24.90’W
LAT andLON cross
here
X
GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT33O 53.00’N and 118O 24.90’W
“X” marksthe spot !
X
X
X
X
SAMPLE PROBLEM #3:LOCATE THE ZUMA BEACH, MALIBU
X
X
GIVEN: ZUMA BEACH, MALIBU IS LOCATED AT34O 01.25’N and 118O 49.50’W
X
X
GIVEN: ZUMA BEACH, MALIBU IS LOCATED AT34O 01.25’N and 118O 49.50’W
X
X
GIVEN: ZUMA BEACH, MALIBU IS LOCATED AT34O 01.25’N and 118O 49.50’W
X
X
GIVEN: ZUMA BEACH, MALIBU IS LOCATED AT34O 01.25’N and 118O 49.50’W
LAT andLON cross
here
X
X
GIVEN: ZUMA BEACH, MALIBU IS LOCATED AT34O 01.25’N and 118O 49.50’W
“X” marksthe spot !
X
SUMMARY:
TO PLOT A LOCATION ON A CHART
1. FIND THE LATITUDE LINE
2. FIND THE LONGITUDE LINE
3. PLACE AN “x” WHERE THE TWOLINES CROSS
“X” marksthe spot !