Raster vs Vector

[DanEvans]

Hi,

I've been working with ArcGIS seriously for nearly a year in my job and have learnt a huge amount in that time and been able to do some very cool and useful stuff for the company. It's nearly all been vector stuff though, the only time really I have used rasters is to scan in old project plans and georeference them to our vector data. I know that rasters are also used for stuff like elevation data but so far we've no need to take elevation into account in what I do...

One thing I did was to look at statistics for gas escapes in terms of 500m square OS facets in polygon vector form - e.g. spatially joining points representing escapes to the 500m squares and then symbolising with darker colours for more escapes, that sort of thing. I'm wondering if that's the sort of thing that would suit raster analysis... as it's basically equal sized cells containing a value each.

What sort of things could I do if the 500m polygons were in raster format instead? Can you even have pixels/cells 500m x 500m? Is there any benefit to representing this sort of data in that way?

Any help appreciated,

Cheers
Dan

[JohnSobetzer]

Not a direct answer to your question but you might Google on vector vs raster data in GIS.  For example here's a quick summary: http://bgis.sanbi.org/gis-primer/page_19.htm or http://courses.washington.edu/gis250/lessons/raster_analysis1/index.html

[MarkEllis]

Your example of distribution of gas escapes would fit raster analysis well.  Many of the spatial analyst tools could be put to use - distance, density, amounts, proximity, etc.

[DanEvans]

Thanks for the replies. I've had a play with the facet data and worked out how to convert it into raster form and back again. Unfortunately we don't have a spatial analyst license but I've had a look at the help files and some demos and now have more of an idea of what can be done with rasters.

Cheers
Dan