A good pilot is always learning -- how many times have you heard
this old standard throughout your flying career? There is no truer
statement in all of flying (well, with the possible exception of
"there are no old, bold pilots.")
Aero-News has called upon the expertise of Thomas P. Turner,
master CFI and all-around-good-guy, to bring our readers -- and us
-- daily tips to improve our skills as aviators.
Some of them, you may have heard before... but for each of us,
there will also be something we might never have considered before,
or something that didn't "stick" the way it should have the first
time we memorized it for the practical test.
Look for our daily Aero-Tips segments, coming each day to you
through the Aero-News Network.
Take a look at the two satellite images below:
What's the difference between the two simultaneous satellite
The most prominent feature of the top image is the extremely
distinct line between visible clouds and apparently clear sky,
running northeast/southwest from just west of Detroit, MI to
somewhere just west of Houston, TX. That's an amazingly sharp edge
of clouds over a great distance, isn't it? The bottom image
doesn't show this distinct line. In fact, it shows areas of
extensive cloudiness in southeast Michigan and Ohio that appears
clear in the top image.
The difference is that the top image is the visible clouds
picture, essentially a satellite-based snapshot of the cloud tops,
looking down. The distinct line is the earth's terminator, or line
between night and day. There's nothing visible to the east of the
terminator because it's in the dark-the satellite can't see the
clouds over Ohio.
The lower image is the infrared satellite image. It detects
cloud tops by comparing thermal energy being reflected back into
space. Although it's not perfect, the infrared image indeed shows
areas of clouds at night-providing useful information when the
visible image shows misleading data.
Aero-tip of the day: Don't trust any one source
of weather data alone. Compare weather information to complementary
observations and forecast products to get a more complete