THE BASICS OF PLOTING OCEAN LOCATIONS the GPS LATITUDE & LONGITUDE Robert Perry

DISCLAIMER: The images, maps and diagrams in this presentation were taken from the public domain on the world wide web. This slide show is for non- commercial, educational purposes ONLY !

LATITUDE & LONGITUDE LINES: LATITUDE Lines go east and west. LONGITUDE Lines go north and south. Map:

a GLOBAL POSITIONING SATELLITE RECEIVER is used to measure and record the LATITUDE and LONGITUDE of a LOCATION in DEGREES, and MINUTES.

LATITUDE LONGITUDE latitude 34 O 06.54’ N Degrees Minutes North of equator

Ground Tracks for the 27 Global Positioning Satellites (effective 9/28/98)

At least 4 GPSatellites must be locked in to give Latitude, Longitude, Elevation and GPS Time. X Y Z & T

SAMPLE ACTIVITY: PLOT THE POSITIONS OF A FEW LOCATIONS ON A CHART

Materials needed for this sample activity: Copies of Santa Monica Bay or southern California chart pencils Ruler or straight-edge Location data (from GPS)

STEPS TO FOLLOW IN THIS ACTIVITY: 1- FIND THE LATITUDE LINE AND DRAW IT IN PLACE USING YOUR PENCIL AND RULER. 2- FIND THE LONGITUDE LINE AND DRAW IT IN PLACE USING YOUR PENCIL AND RULER 3. PLACE AN “X” TO MARK THE SPOT WHERE LATITUDE AND LONGITUDE LINES CROSS.

Our activity area

WHAT DOES THE NAUTICAL CHART TELL YOU ?

1. LOCATION OF LAND AND LANDMARKS.

2. LOCATION OF OCEAN AND DEPTHS.

DEPTHS ARE SHOWN BY DARKER COLORS

3. DEGREES OF LATITUDE (horizontal lines).

DEGREES of LATITUDE GET BIGGER GOING NORTH

4. DEGREES OF LONGITUDE (vertical lines).

DEGREES of LONGITUDE GET BIGGER GOING WEST

NOTICE THAT THE GRIDLINES ON THIS CHART ARE EQUAL TO 5’ (minutes) EACH.

SAMPLE PROBLEM #1: LOCATE THE SANTA MONICA PIER

GIVEN: THE SANTA MONICA PIER IS LOCATED AT 34 O 00.50’N and 118 O 29.10’W

GIVEN: THE SANTA MONICA PIER IS LOCATED AT 34 O 00.50’N and 118 O 29.10’W First, we’ll draw the LATITUDE LINE using your ruler and a pencil.

GIVEN: THE SANTA MONICA PIER IS LOCATED AT 34 O 00.50’N and 118 O 29.10’W 34 O 00.50’N (green line) is just a tiny bit North of 34 O 00.00’N

GIVEN: THE SANTA MONICA PIER IS LOCATED AT 34 O 00.50’N and 118 O 29.10’W 34 O 00.50’N [our location is someplace along this green line]

GIVEN: THE SANTA MONICA PIER IS LOCATED AT 34 O 00.50’N and 118 O 29.10’W Next, let’s draw the LONGITUDE LINE using your ruler and a pencil.

GIVEN: THE SANTA MONICA PIER IS LOCATED AT 34 O 00.50’N and 118 O 29.10’W 118 O 29.10’W (yellow line) is just a tiny bit before 118 O 30.00’W

GIVEN: THE SANTA MONICA PIER IS LOCATED AT 34 O 00.50’N and 118 O 29.10’W The Santa Monica Pier is located where the two lines cross each other.

GIVEN: THE SANTA MONICA PIER IS LOCATED AT 34 O 00.50’N and 118 O 29.10’W “X” marks the spot ! X

SAMPLE PROBLEM #2: LOCATE THE MANHATTAN BEACH PIER X

GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT 33 O 53.00’N and 118 O 24.90’W X

GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT 33 O 53.00’N and 118 O 24.90’W 33 O 53.00’ is between 33 O 50’ and 33 O 55’ X

GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT 33 O 53.00’N and 118 O 24.90’W X

GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT 33 O 53.00’N and 118 O 24.90’W X

GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT 33 O 53.00’N and 118 O 24.90’W LAT and LON cross here X

GIVEN: THE MANHATTAN BCH. PIER IS LOCATED AT 33 O 53.00’N and 118 O 24.90’W “X” marks the spot ! X X

X X SAMPLE PROBLEM #3: LOCATE THE ZUMA BEACH, MALIBU

X X GIVEN: ZUMA BEACH, MALIBU IS LOCATED AT 34 O 01.25’N and 118 O 49.50’W

X X GIVEN: ZUMA BEACH, MALIBU IS LOCATED AT 34 O 01.25’N and 118 O 49.50’W

X X GIVEN: ZUMA BEACH, MALIBU IS LOCATED AT 34 O 01.25’N and 118 O 49.50’W

X X GIVEN: ZUMA BEACH, MALIBU IS LOCATED AT 34 O 01.25’N and 118 O 49.50’W LAT and LON cross here

X X GIVEN: ZUMA BEACH, MALIBU IS LOCATED AT 34 O 01.25’N and 118 O 49.50’W “X” marks the 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 TWO LINES CROSS

“X” marks the spot !