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View Full Version : Google Earth / Multimap


120torque
27th Aug 2007, 08:45
I have just driven to a landing site to double check accessibility which as seen on google earth/multimap looks a reasonable site to get in/out from. However, the nice looking green field (on google earth) just south of an industrial unit turns out to be a local council estate dumping ground (fridges, mattresses, druggies!, etc) with an 30ft wall on one side and buidlings on another! As it's not always pactical to drive to private sites first - I have a fewof q's:

1) Is the use of google earth etc for determining landing sites legally acceptable as the only means of survey for commercial ops ?

2) What other means of site survey other than driving there/flying over can be used ?

3) Did operators always go and visit private sites before the days of online aerial mapping ?

One funny thing is - I am now trawling through google earth to find golf courses, cricket grounds etc as an alternative site!

farsouth
27th Aug 2007, 08:49
Google Earth pictures are not real-time...........

The one that shows my street is about 6 years old.

Would you rely on a survey of a site last updated 6 years ago?????

NickLappos
27th Aug 2007, 13:20
The Google earth pic of my house is newer than 24 months, but older than 15 months, based on the improvements that it shows and what it doesn't. A weakness is that they do now tag the view with its date. Does anyone know how to extract that from the web site?

Do you also know that you can rotate the view downward so you can see the terrain elevation in a sort of 3-D? A very nice feature.

Brilliant Stuff
27th Aug 2007, 15:27
Google uses old pictures especially over here in Europe. The States is their home market so they will be more up to date.

Commercial operators do a site survey by foot most times when you knew they could be tricky. Golf courses of course are ideal or cricket pitches.

When I was ignorant of Cricket I landed on the "wicket" thinking this will do nicely. Only years later it dawned on me that was the one place I should not have landed.

Camp Freddie
27th Aug 2007, 18:00
my home airfield in the UK, until recently was not really visible at all on google earth because the resolution was so poor that individual towns were barely identifiable.

however a high resolution photo has now appeared but curiously seems to date from aboout 1998-99 :(

but at my home the picture is not much more than 1 year old, and google maps and google earth are currently showing different age photos from each other.

where the pictures are the same I find that the google maps picture is a little clearer but have no idea why ?

CF

Ioan
27th Aug 2007, 18:49
Around here both multimap and google earth are very low resolution, literally grey blobs for towns and green expanses for fields.
http://maps.live.com/ seems to use more recent and high res photos...
not sure how true that is in other areas

PANews
27th Aug 2007, 20:59
Although I use the Google Earth maps for the terrestrial aspects of event planning I would never trust them for something as precise as flight planning.

Case in point I have used commercial helicopter operators for joy rides 7 years now and both [Cabair and Atlas] undertook a personal site survey before operating. Those nasty HT pylons do not very threatening in the Google images but they required the use of a twin rather than a single to undertake the tasks.

As if to underline the fickleness of the images locally there is a site by the M25 where there is a giant distribution building that has been there for 5 years and just north of it there is a superstore operated by a different chain that was built three years later.

According to the current images the giant distribution building is a field of mud but the smaller store is there ... or it was 6 monhs ago! Now that cell of the on-line images has stepped back to the same dating as the giant distribution building and Tesco has simply disappeared! [That should make a lot of people happy of course ... but it is still there really!].

With that sort of spooky behavior this is certainly an unreliable resource. Maps live shows the same dated [5-7 years old] images.

topendtorque
28th Aug 2007, 14:07
Re the 3D effect of Google,
some of our more computer literate 'pastoralist' clients now send a briefing by email of the job to be done, complete with google by plan and google by elevation. I.E. how to put the blasted cattle into the yard etc. etc.

Just so often feel like replying with the same map flagging where the fence was down last and every year and an elevation mode with said cattle in full flight escaping.

But no, a mind reader one must be to be ahead of such inconsequental mind bending problems and exudingly polite and silent also.

120torque
28th Aug 2007, 16:48
Just found something interesting. Looked at the original site with http://maps.live.com/ - In 2D mode it has a very outdated view. However, when choosing the 3D view it had a very upto date view. e.g In 2d it shows 2 buildings with a grass bit in the middle - ok for landing - in 3d it shows the new wall surrounding a secure compound - Not that great!.

Will try a few more postcodes...

DirtyDitch
29th Aug 2007, 11:10
As requested above by another does anyone know how to exract the date that an image was taken or at least applied to the site.
I used a similar version of what google earth is doing now but back in 1986. This was kindly provided by our nice people working alongside the Thames. With much dismay it was taken away near the time that the Berlin wall came down.
I recently heard that someone is getting divorced due to the uncannily clear and recent shot of a certain car parked at a place it shouldn't have been.

Bullethead
29th Aug 2007, 11:40
To find out when the runs were done go to the 'Layers' dropdown on the LHS of the Google Earth screen and scroll down to the bottom and you'll see a box by the name of 'Digital Globe Coverage'. Click on th '+' and it'll open up a bunch of coverages. As you click on each one an outline of the relevant coverage will appear on the image.

To flatten the image so you can see it in relief go to the top RH corner of the image and click and hold on the RH end of the crossbar above the thing that looks like a compas rose. The other end of the cross bar will get you vertical again.

Clear as mud probably.

Regards,
BH.

Tallguy
29th Aug 2007, 12:16
Just to include my t'pence worth -

I viewed a hospital site on foot recently and there's a bloody great big chimney in the area, when looking, post foot viewing, on goole earth you can see the shadow of the chimney on the ground, go to 3D view and lo and behold the chimney magically disappears, so personally no I would never rely souly on aerial pictures on the internet.

To answer the original question regarding site surveying, when it was not possible for me as an ops bod to visit a site I used to contact local operators and / or pilots I knew in that area, and would request they view the site on my behalf, being the small industry we are I never found this to be a problem in the slightest and it always worked rather well