| If you were travelling somewhere you couldnt use your own cellphone, what
would offer you the best mix of price and convenience?
[ ] Using a calling card
[ ] Using a public, hotel or office phone
[ ] Renting a cellphone (with airport pickup and dropoff)
[ ] A satellite cellphone you brought with you
[ ] Your normal cellphone, equipped with a special card or chip
You may add a comment inside the square brackets:
[ ] |
| Hans-Georg, the Trimble page you have previously quoted says regarding the
errors, The errors theyre checking for are called ephemeris errors
because they affect the satellites orbit or ephemeris. These errors are
caused by gravitational pulls from the moon and sun and by the pressure of
solar radiation on the satellites.
Satellites at that altitude are NOT affected by atmosphere, nor do they
periodically fire small engines to raise their orbit.
The satellite orbit pertubations are caused by gravity and solar radiation. |
| Providers may charge a premium on top of standard international call rates
for the convenience of being able to pull out a satellite cellphone instead
of having to borrow someone elses phone or use a calling card. What would
you be willing to pay for this convenience premium?
[ ]No more than standard international direct-dial rates
[ ]Up to 20% more than standard international direct-dial (IDD) rates
[ ]Up to 50% more than IDD rates
[ ]Double the price of IDD rates
[ ]Three times the price of IDD rates
[ ]More than three times the price of IDD rates
You may add a comment inside the square brackets:
[ ] |
| A satellite that orbits within a few hundred miles of the
earths surface experiences friction from the thin atmosphere
that exists at those altitudes. Eventually the satellites
altitude will decrease until atmospheric friction causes the
satellite to plunge earthward out of orbit. The lifetime of a
satellite depends on its orbit, the satellites orientation in
its orbit, and the size, shape, and weight of the satellite. A
large, light satellite will probably reenter the earths
atmosphere sooner than a small, heavy satellite that orbited at
the same altitude because the large satellite has more surface
area and experiences more atmospheric friction. At an orbital
altitude of 200 km (120 mi), a satellite will likely last from a
week to three months. At 300 km (190 mi), a satellite may stay
in orbit for two years or more. Satellites that orbit above 1000
km (620 mi) will stay aloft for thousands of years. |
| As cellular networks spread over more of the world and phone companies do
deal
s with each other, you may be able to take your standard cellphone to more
places. Given the pricing preferences youve just expressed, how often you
would have to use a satellite cellphone to feel you got good use out of it?
[ ]Once a week
[ ]Once a month
[ ]Once a quarter
[ ]Once a year
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[ ] |
