COPY LATITUDE/LONGITUDE Mr. Rocco COPY THE LATITUDE/ LONGITUDE EARTH POINT LOCATING SYSTEM OPERATES BY USING STAR ANGLES COPY LATITUDE DESCRIBES YOUR LOCATION NORTH OR SOUTH OF THE EQUATOR IN DEGREES (0-90) HERE’S HOW THE STAR ANGLE TELLS YOUR DEGREE OF LATITUDE LIGHT FROM POLARIS (NORTH STAR) SHINES ON EARTH AT NIGHT People here look straight up…90o to their horizon..their latitude =90 deg north Anyone along here sees Polaris 450 to there horizon..latitude =450 north
People here see the N Star LINES OF 00above LATITUDE ARE horizon…latitude ALSO CALLED =0O PARALLELS Altitude of Polaris and Latitude WHAT IS THIS GUY’S LATITUDE ? POLARIS
54 DEGREES 36 DEGREES HORIZON LINE WHAT IS HER LATITUDE ?
320 580
900 COPY
LINES OF LATITUDE ARE CALLED PARALLELS…REMEMBER “LAT IS FLAT”
49th Parallel?
•The 49th parallel of north latitude forms part of the international boundary between Canada and the United States •The 38th parallel divides North Korea from South Korea •The 17th parallel divided Vietnam up until 1975
COPY LONGITUDE DESCRIBES YOUR LOCATION EAST OR WEST OF THE PRIME MERIDIAN IN DEGREES(0-180)
LINES OF LONGITUDE ARE ALSO CALLED MERIDIANS ALL LONGITUDE LINES RUN FROM THE NORTH POLE TO THE SOUTH POLE. 00 LONGITUDE ,ALSO CALLED THE PRIME MERIDIAN ,RUNS THROUGH GREENWICH, ENGLAND
COPY HERE’S HOW IT WORKS COPY THE EARTH SPINS FROM WEST TO EAST 150 /HOUR
24 HRS 3600 0 = 15 /HR
REMEMBER THIS NUMBER!!! COPY TO DETERMINE YOUR LONGITUDE YOU MUST:
1. DETERMINE THE TIME DIFFERENCE BETWEEN WHERE YOU ARE AND GREENWICH COPY 2. MULTIPLY THE TIME DIFFERENCE BY 150 (THE EARTH ROTATES FROM WEST TO EAST 150 HOUR) 3. IF YOUR TIME IS EARLIER THAN GREENWICH TIME YOU ARE TO THE WEST…IF LATER IN THE DAY YOU ARE EAST PRIME MERIDIAN
0 0LONGITUDE SOLAR NOON
A. 7 AM D. 6 PM B.10 AM C. 2 PM
WEST EAST EARTH SPIN
THE LATITUDE OF: A= 75 DEG WEST B=30 DEG WEST
C= 30 DEG EAST D= 90 DEG EAST WHAT IS YOUR LONGITUDE IF: IT IS SOLAR NOON AT YOUR 1. LOCATION AND 10AM ON THE PRIME MERIDIAN?
THE TIME DIFFERENCE IS 2 HOURS…2X150=300 YOU ARE LATER IN THE DAY SO YOU ARE EAST OF THE PRIME MERIDIAN…300 E.LONGITUDE COPY 2. • IT IS 6PM IN GREENWICH AND SOLAR NOON AT YOUR LOCATION. What is your longitude? • 900 WEST 3. IT IS 8AM IN GREENWICH AND 3 PM WHERE YOU ARE 1050 EAST 4. YOUR TIME IS 2AM AND IT IS NOON IN GREENWICH 1500W
Sextant? Hold the instrument vertically and point it toward the celestial body. Sight the horizon through an unsilvered portion of the horizon mirror. Adjust the index arm until the image of the sun or star, which has been reflected first by the index mirror and second by the silvered portion of the horizon mirror, appears to rest on the horizon. The altitude of the heavenly body can be read from the scale on the arc of the instrument’s frame. GMT: Greenwich Mean Time? COPY How specific can degrees go?
• To zoom in to a specific point on earth, lat/long narrow down to minutes and seconds •1O = 60‘ (minutes) • 1’ = 60“ (seconds) • EX: 73O 30’ 00” W = 73.5 O W