**Grid scale**

July 27 2010 |
2 comments

Categories:
Map Data

according to the blog:

http://blogs.esri.com/Support/blogs/mappingcenter/archive/2009/12/03/Mathematical-Relationships-among-Map-Scale_2C00_-Raster-Data-Resolution_2C00_-and-Map-Display-Resolution.aspx

If I have to generate a map 1:25000 how much should be the size of the grid?

How to calculate the value of 4000?

With the 30-meter DEM I can generate a 1:25,000 scale map?

### Mapping Center Answer:

I am attaching a table that is still in progress -- once it is complete, we will write a blog entry about it. You will see that for a map at a scale of 1:24,000, your best bet is to use 10m DEM data rather than 30m data.

I am not quite sure what you mean about calculating a value of 4,000 -- perhaps if you sent us some additional informaton, we could help you with this.

**Not quite sure what you mean**posted by Aileen Buckley on Mar 11 2011 3:42PM

As we noted in a recent blog entry: An equation you can use that relates map scale expressed as a representative fraction(1/x), DEM cell resolution, and map display resolution is:

1/x = 1 / (DEM cell ground size [cm/cell] × map pixel density [pixels/cm]), so that 1 centimeter on the map represents x centimeters on the ground.

You can read more about this here: http://blogs.esri.com/Support/blogs/mappingcenter/archive/2011/02/28/dem-resolution-output-map-pixel-density-and-largest-appropriate-map-scale.aspx

If you would like to post a comment, please login.

here is the value?posted by Alexander Pineda on Aug 13 2010 3:35PMIn the simple case of a square cell digital elevation model (DEM), such 30m x 30m UTM grid cells, the optimal ground dimensions of the pixels on the map should be the same (or larger) than the DEM spatial resolution. For example, at a map pixel density of 4000 pixels per meter, the optimal mapping scale would be 1/x = 1 / (30 m/pixel × 4000 pixels/m) = 1:120,000 (or smaller). This recommendation, of course, is for large to medium scale mapping where there is minimal scale distortion across the map projection.