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1. USE RULER ON GOOGLE MAPS HOW TO
2. USE RULER ON GOOGLE MAPS INSTALL
3. USE RULER ON GOOGLE MAPS 32 BIT
4. USE RULER ON GOOGLE MAPS FULL
5. USE RULER ON GOOGLE MAPS PRO

Check it against any to the tables posted here and the numbers will match.īased on all the info provided, I have built a function that gives the best z applied to a map when you want to have a horizontal line that represents N% of the displayed Map. I have used this hundred of time and overlaying it with actually field survey data and its always been correct. If you want feet divide that 0.3048Īs for sources I essencial reversed engineer about 5 years ago from various bit of info and documentation I found on the web including Google and MS mapping support sites. If you screen capture a 1000 x 1000 pixel image of that area the dimension are 105.56 meters square. That is the length and height of one pixel from an image at latitude 45 at zoom level 20.

Now lets say our image is at latitude 45. Lets say I have an image at zoom level 20 (as zoomed as they currently let you get) Take 0.009330692 (Zoom 24 at equator) double it for zoom 23, again for zoom 22, again for zoom 21 and one last time for zoom 20.

USE RULER ON GOOGLE MAPS HOW TO

Now for an example of how to use the above data. Why this is level 24 was chosen I don't know however as someone else here worked out 0 gets you down to one 256 pixel tile for the earth.

USE RULER ON GOOGLE MAPS 32 BIT

32 bit integers are also efficient to store and process. This is a logical choice as it yields global accuracy to about one centimeter which is plenty for aerial imagery.

USE RULER ON GOOGLE MAPS FULL

They then took that and divided it by a full 32 bit integer. (note in a previous post someone used a value of 40,075,160 I've seen this in Wikipedia a few places and it's incorrect. So back 15-20 year ago someone took WGS-84 as base data. What you need for these images to be used with any accuracy is to know the dimension of each pixel then scale the image according to whatever your overlaying it with. Scale ratios are relative to printed documents not computer screens. Well its not really a legitimate question to start with. Unit at Latitude = (Cosine of Latitude) X (Unit at Equator)