Google Earth Glider on Tow USAFA

ContestID67 wrote:
> Cool.
>
> I see another glider on tow at
> 38°57'16.14"N 104°49'25.29"W

OK, While we're at it :-) Greater Boston Soaring Club gliders at:
42°25'49.98"N 71°47'47.70"W
42°25'54.75"N 71°47'03.60"W
42°25'23.84"N 71°47'25.17"W
42°25'38.01"N 71°47'44.61"W

Tony V.

ContestID67 wrote:
> On Jul 22, 9:03 pm, cslecl...@m wrote:
>> Here is a strange one. Take a look at the glider over the end of runway
>> 36 at Seminole-Lake Gliderport in Florida. The glider appears to be on
>> tow but there is no towing aircraft? Doesn't look like a motorglider?

I found it in Google Earth, thanks to coordinates provided
by ContestID67. There is a Google Community placemark for it
that says it's a motorglider taking off. I don't think so,
because there's no shadow of a motor, either on the top of the plane,
or on the ground. And I think it's also too high to be taking off.

>> The shadow of this glider on the ground does not appear to be small
>> enough to place the plane very high

It's not the size of the shadow that is telling, but the position.
Look at the shadows of things on the ground. It looks like early
afternoon, when shadows are almost minimal. Now take another look
at the shadow of the glider in question. The shadow is a long ways
from the plane, as compared to other shadows. This plane is a few
hundred feet up, I think. My guess is that the pilot is overflying
the airport before turning around to land.

Aside from that, this gliderport brings back memories of living
in Florida. In the winter, thousands of hawks can be seen circling
in thermals over the I-4 corridor, about 17 miles to the south of
the gliderport.

> Anyway, after interpreting the directions show on the web site and
> following along on Google Earth, the coordinates are;
>
> 28°24'28.93"N 81°50'16.72"W

On Jul 23, 9:21 pm, Jay Ts <DoNotRe...@example.com> wrote:
> ContestID67 wrote:
> > On Jul 22, 9:03 pm, cslecl...@m wrote:
> >> Here is a strange one. Take a look at the glider over the end of runway
> >> 36 at Seminole-Lake Gliderport in Florida. The glider appears to be on
> >> tow but there is no towing aircraft? Doesn't look like a motorglider?
>
> I found it in Google Earth, thanks to coordinates provided
> by ContestID67. There is a Google Community placemark for it
> that says it's a motorglider taking off. I don't think so,
> because there's no shadow of a motor, either on the top of the plane,
> or on the ground. And I think it's also too high to be taking off.
>
> >> The shadow of this glider on the ground does not appear to be small
> >> enough to place the plane very high
>
> It's not the size of the shadow that is telling, but the position.
> Look at the shadows of things on the ground. It looks like early
> afternoon, when shadows are almost minimal. Now take another look
> at the shadow of the glider in question. The shadow is a long ways
> from the plane, as compared to other shadows. This plane is a few
> hundred feet up, I think. My guess is that the pilot is overflying
> the airport before turning around to land.
>
> Aside from that, this gliderport brings back memories of living
> in Florida. In the winter, thousands of hawks can be seen circling
> in thermals over the I-4 corridor, about 17 miles to the south of
> the gliderport.
>
> > Anyway, after interpreting the directions show on the web site and
> > following along on Google Earth, the coordinates are;
>
> > 28°24'28.93"N 81°50'16.72"W

Shadows appear to me to reflect a sun angle around 45degs, making
length near to height of object (look at the edge of the house
shadow. Figure the road is 18-20ft wide, so the glider span appears
about 55-60ft. The large horizontal would indicate to me that is
likely a G109B on departure at approximately 140ft-170ft agl.

Frank Whiteley

On Jul 22, 7:03 pm, cslecl...@m wrote:
The shadow of this glider on the ground does not appear
> to be small enough to place the plane very high

Since the sun can be assumed to be at infinite distance from the earth
its rays are as near to parallel as makes no difference. The size of
the shadow should not change with height of the aircraft. The shadow
will become more diffuse as height increases.

I've often wondered if the width of a potential landing site could be
estimated by laying the glider shadow over it. Usually to busy to
try it and suspect that it would only be effective at low altitude
when it's too late to pick another place.


Andy