Rogue's Gallery Almost Got Me in Trouble

writes:

CAP has been conducting searches every day since the aircraft was
reported missing. According to the news, there were 20 sorties last
Saturday, and 10 (I think) on Sunday. The search is continuing.

Just out of curiosity, wouldn't a few good satellite photographs allow
a much wider area to be examined more quickly?

--
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"Mxsmanic" wrote in message
...
writes:

CAP has been conducting searches every day since the aircraft was
reported missing. According to the news, there were 20 sorties last
Saturday, and 10 (I think) on Sunday. The search is continuing.

Just out of curiosity, wouldn't a few good satellite photographs allow
a much wider area to be examined more quickly?

--

The fuel value of moving a spy satellite just 1 degree to cover a specific
area would pay for several 100 if not 1000s of CAP missions. Then you have
to have the NRO use the manpower to examine the images. Where the CAP pilots
are volunteers.

Gig 601XL Builder writes:

The fuel value of moving a spy satellite just 1 degree to cover a specific
area would pay for several 100 if not 1000s of CAP missions.

I didn't say anything about moving a satellite, nor did I say anything
about spy satellites. There may have been satellites already covering
the area. Commercial satellites already have enough resolution to
spot wreckage.

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"Mxsmanic" wrote in message
...
Gig 601XL Builder writes:

The fuel value of moving a spy satellite just 1 degree to cover a
specific
area would pay for several 100 if not 1000s of CAP missions.

I didn't say anything about moving a satellite, nor did I say anything
about spy satellites. There may have been satellites already covering
the area. Commercial satellites already have enough resolution to
spot wreckage.


So you think those pictures on Google Earth are real time. Satellites both
commercial and government are in orbits that are designed to cover areas of
interest. To task a satellite to cover a specific area that isn't under its
flight path requires fuel to be used. The chances of any given place on any
given week being covered is low. The exception to this is places where the
government has special interest. I'm sure the Mid East is covered pretty
well about now.

Gig 601XL Builder writes:

So you think those pictures on Google Earth are real time.

I didn't say anything about Google Earth, either.

You can save a lot of time by concentrating on what I actually write,
and skipping the speculation.

--
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On Fri, 6 Oct 2006 10:49:23 -0500, "Gig 601XL Builder" wrDOTgiaconaATcox.net
wrote:

So you think those pictures on Google Earth are real time. Satellites both
commercial and government are in orbits that are designed to cover areas of
interest. To task a satellite to cover a specific area that isn't under its
flight path requires fuel to be used. The chances of any given place on any
given week being covered is low. The exception to this is places where the
government has special interest. I'm sure the Mid East is covered pretty
well about now.

Not quite. There are few low-earth orbits where a given satellite can't see the
entire Earth in a week. The major exceptions are those cases where the
satellite inclination (orbit tilt with respect to the equatorial plane) low; in
these cases, the satellite won't pass over higher latitudes at all.

In any case, satellites that take imagery in natural light are generally in a
sun-synchronous orbit. In this kind of orbit, the satellite's orbit plane stays
in a fixed relationship with the sun. In this way, the satellite passes
overhead at the same approximate ground time each day (and 12 hours later at
night, too). The satellite's photos then always have the sun at the same local
angle to optimize the images taken.

The other factor is the altitude of the spacecraft. The lower the orbit, the
closer the vehicle is to the target and the higher the photo resolution (too
low, of course, and you quickly use up your propellant just keeping the thing in
orbit). But by flying low, you lessen your Field Of Regard... the satellite
can't see as much of the surface at given moment. A given target may fall
right between two adjacent satellite passes, for instance. But unless the orbit
meets some pretty specific criteria, it should pass over that target area within
a couple of days.

A satellite CAN change its orbit to catch that target, but the propellant cost
is pretty fierce. It's traveling at ~18,000 MPH; changing the orbit may require
the expenditure of enough propellant to change the velocity by ANOTHER 2,000
MPH. It's a lot cheaper just to put up a second satellite with complimentary
coverage.

As to why the news media don't have fresh S/C pictures every time something
happens, the answer is "tasking." These satellites are pretty busy, and
resources (including onboard storage capacity) have to be carefully planned.

Ron Wanttaja

Mxsmanic wrote:
writes:

CAP has been conducting searches every day since the aircraft was
reported missing. According to the news, there were 20 sorties last
Saturday, and 10 (I think) on Sunday. The search is continuing.

Just out of curiosity, wouldn't a few good satellite photographs allow
a much wider area to be examined more quickly?

--
Transpose mxsmanic and gmail to reach me by e-mail.


Spy satellites work well when you don't want someone to know you are
watching. ;)

If there are survivors, they can signal a live, low-flying aircraft.
The search crew looks not only straight down, but sideways (Searches
can be parallel lines as close as necessary, though 1-mile spacings are
usual. So we can be looking about 1/2 mile sideways, more or less.)
It's surprising how aircraft tend to slide under trees, etc. and can't
be seen from straight up. Many times, we have to look for "clues",
such as ground damage, burn marks in trees, etc. Unfortunately, many
wrecks aren't recognizable--just scattered aluminum.

With multiple aircraft, we can cover quite a bit of territory
simultaneously. If an aircraft is found, we can circle or otherwise
communicate directly with ground teams to lead them to a site.

Speaking of ground teams, there are quite a few people working a search
who are not in the air. Mission base has people handling information,
planning, communications, logistics, dealing with families and other
officials, etc. Ground team members are also trained in their
functions. They are all volunteers.

A major advantage is that the crews work for free! Actually, we pay
for the privilege since we do spend money training, etc.

In addition, CAP members are qualified to assist in other types of
disasters, as part of the national Incident Command structure. We've
worked floods, hurricanes, whatever; this is either with air capability
or just as food-carrying ground pounders.