I'm just interested in finding out that's all.

cheers

On Thu, 05 Jan 2006 22:14:22 +0000, PetDragon wrote:

I'm just interested in finding out that's all.

http://www.ordnancesurvey.co.uk/oswebsite/getamap/

Or on handy, portable, paper at many bookshops.



Mike

"Mike Causer" wrote in message
newsan.2006.01.05.22.16.59.635307@firstnamelastn ame.com.invalid...
On Thu, 05 Jan 2006 22:14:22 +0000, PetDragon wrote:

I'm just interested in finding out that's all.

http://www.ordnancesurvey.co.uk/oswebsite/getamap/

Or on handy, portable, paper at many bookshops.



Personally, I've found that the Google Earth program is better for this sort
of thing. Ordnance Survey maps are ok but the contour lines are not always
clear, especially in built up areas.

Victor

I found that Google Earth was rather inaccurate. According to my airspace
map Lasham airfield is 618 feet above sea level. However google earth
recently reckoned it was below 600 feet in most spots if I remember right.
Only a few feet, but... but...

Yes for where I live in London the OS maps are pretty useless in determining
my height as the contours are unreadable on getamap.

-Mike

"Victor West" wrote in message
...

"Mike Causer" wrote in message
newsan.2006.01.05.22.16.59.635307@firstnamelastn ame.com.invalid...
On Thu, 05 Jan 2006 22:14:22 +0000, PetDragon wrote:

I'm just interested in finding out that's all.

http://www.ordnancesurvey.co.uk/oswebsite/getamap/

Or on handy, portable, paper at many bookshops.



Personally, I've found that the Google Earth program is better for this
sort of thing. Ordnance Survey maps are ok but the contour lines are not
always clear, especially in built up areas.

Victor

But was it at high tide or low tide

"TerminalVelocity" mike(underscore)j(underscore)rubin(at)yahoo.co.uk wrote
in message ...
I found that Google Earth was rather inaccurate. According to my airspace
map Lasham airfield is 618 feet above sea level. However google earth
recently reckoned it was below 600 feet in most spots if I remember right.
Only a few feet, but... but...

Yes for where I live in London the OS maps are pretty useless in
determining my height as the contours are unreadable on getamap.

-Mike

"Victor West" wrote in message
...

"Mike Causer" wrote in message
newsan.2006.01.05.22.16.59.635307@firstnamelastn ame.com.invalid...
On Thu, 05 Jan 2006 22:14:22 +0000, PetDragon wrote:

I'm just interested in finding out that's all.

http://www.ordnancesurvey.co.uk/oswebsite/getamap/

Or on handy, portable, paper at many bookshops.



Personally, I've found that the Google Earth program is better for this
sort of thing. Ordnance Survey maps are ok but the contour lines are not
always clear, especially in built up areas.

Victor

google earth seems to think 460ft or 140 meters, using the OS online I was
able to determine this to be fairly spot on. Although I can't see the
contour lines because of the buildings in my street(bloody neighbours) I
know the surrounding area pretty well. Call it an educated assumption that
google earth must me right.
I should have a gadget that works it our for wherever I am. Good job I am
not a pilot.....

Lucky me
Thanks

"Alan" wrote in message
...
But was it at high tide or low tide

"TerminalVelocity" mike(underscore)j(underscore)rubin(at)yahoo.co.uk
wrote in message ...
I found that Google Earth was rather inaccurate. According to my airspace
map Lasham airfield is 618 feet above sea level. However google earth
recently reckoned it was below 600 feet in most spots if I remember right.
Only a few feet, but... but...

Yes for where I live in London the OS maps are pretty useless in
determining my height as the contours are unreadable on getamap.

-Mike

"Victor West" wrote in message
...

"Mike Causer" wrote in message
newsan.2006.01.05.22.16.59.635307@firstnamelastn ame.com.invalid...
On Thu, 05 Jan 2006 22:14:22 +0000, PetDragon wrote:

I'm just interested in finding out that's all.

http://www.ordnancesurvey.co.uk/oswebsite/getamap/

Or on handy, portable, paper at many bookshops.



Personally, I've found that the Google Earth program is better for this
sort of thing. Ordnance Survey maps are ok but the contour lines are not
always clear, especially in built up areas.

Victor

Mike Causer wrote:
On Thu, 05 Jan 2006 22:14:22 +0000, PetDragon wrote:

I'm just interested in finding out that's all.

http://www.ordnancesurvey.co.uk/oswebsite/getamap/

Or on handy, portable, paper at many bookshops.



Mike

Well said. I have over a hundred at home. It's perfectly
possible to trace contours in built-up areas on an OS 1:25000 map.
With the vertical interval of 5 m combined with local knowledge you can
determine your height to the nearest metre quite easily. My brother's
GPS contraption was out by about 5 metres. I was far too polite to
denigrate his expensive toy. The daft thing is, he can read maps very
well. *rolls eyes upwards*.

Tudor Hughes, Warlingham, Surrey. Alt. 169 m give or take a foot.

On 6 Jan 2006 05:47:35 -0800, "Tudor Hughes" wrote:

My brother's
GPS contraption was out by about 5 metres.

The GPS system wasn't designed to provide an accurate altitude.
Altitude errors can be one-and-a-half to twice the horizontal error.
The altitude that's displayed is the distance from the centre of the
earth less the distance from the centre of the earth of the local
geoid. The local geoid is stored in the receiver and may not be
particularly accurate.

E&OE

--
Alan White
Twenty-eight miles NW of Glasgow, overlooking Loch Goil and Loch Long in Argyll, Scotland.
Web cam and weather:- http://www.windycroft.gt-britain.co....her/kabcam.htm
Some walks and treks:- http://www.windycroft.gt-britain.co.uk/walks/

PetDragon wrote:

I'm just interested in finding out that's all.

Differential GPS is very accurate.

Ordinary hand held GPS isn't too bad if the satellites are in the
right position -- mine usually gets within a metre a so whenever it
gives a steady altitude reading (if the reading drifts it won't be
accurate).

Is WAAS available in your location, and what's its accuracy like?

--
John H

John_H wrote:

Differential GPS is very accurate.

Ordinary hand held GPS isn't too bad if the satellites are in the
right position -- mine usually gets within a metre a so whenever it
gives a steady altitude reading (if the reading drifts it won't be
accurate).

Ordinary GPS can be significantly out! The first thing I did when I got
my device was to take my height - it reckoned (after letting it settle
for a while) that I was at -14m. While that's only 22m out, it's still
quite inaccurate!

Jonathan