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[[image]]

When you look at a satellite images, it's important to know when it was taken. Some images are only updated once a day, others every half-hour. If you are looking at an image that is nearly a day old, it may not be as accurate as you would like for targeting. All of the satellite images have the date and time that the image was taken stamped on the image (generally somewhere near the bottom). That time is usually (thought not always) in UTC, "Universal Time Coordinates." (See box below.)

CONVERTING FROM UTC

In order to avoid confusion among time zones, meteorologists use an international standard time zone, called "Universal Time Coordinates," or UTC. This is also called UT (Universal Time), GMT (Greenwich Mean Time), or indicated with a "Z" (e.g., 1330 Z is 1330 UTC ). In case you're interested, UTC is the time in Greenwich, England! To convert from UTC to your local time, use the following formula:

In Eastern US (Eastern time zone)
when on daylight savings: local = UTC minus 4 hrs
when on standard time: local = UTC minus 5 hrs

In Western US (Pacific time zone)
when on daylight savings: local = UTC minus 7 hrs
when on standard time: local = UTC minus 8 hrs

For other time zones, extrapolate from the conversions above. To convert in the opposite direction (from local to UTC), add the hours instead of subtracting.

The image "Western United States" was taken at 0000Z on May 13, 1997. That's 2000 EDT (8:00 pm EDT.)

Teacher's Guide Page 8.13

Transcription Notes:
misspelled though as thought in text book please transcribe images as [[image]]