topic Re: create a raster with fielddata in ArcGIS Spatial Analyst Questions

create a raster with fielddata

RonWunderink — Tue, 04 Oct 2011 06:16:42 GMT

How can I create a (small) raster and fill it with measured data? I have found how to create a raster, but how to fill it? I can use ArcGIS 9, or 10 including Spatial Analyst.
One of my Biology students would like to add her data this way.

Help will be much appreciated!

Re: create a raster with fielddata

YinghuiCao — Thu, 06 Oct 2011 03:43:02 GMT

Hi Ron,

how is the data originally stored and how would you like to create the raster?

If you have the measured data in shapefiles, then you can convert the feature classes to rasters directly and keep the field values as the cell values.

Re: create a raster with fielddata

RonWunderink — Thu, 06 Oct 2011 07:44:44 GMT

Dear Cathy,
thanks for your reply, the data is stored in a spreadsheet.
However I got an answer via another way (translated from Dutch; thanks to A.Schipper RU):
There are (at least) 2 ways:
1. if the coordinates of each measuring point are known - make a .txt file with these x, y-coordinates and the measured values (one point on eacht row). make a shp file (ArcCat) with these points and convert it to a raster in ArcMap.
2. with 'ASCII to Raster' (ArcMap) you can convert an ASCII, or .txt, file directly into a raster. Make sure that each value is on the correct place in the file, like you can do with a spreadsheet.
The first 6 rows must have the following info:
ncols XXX
nrows XXX
xllcorner XXX
yllcorner XXX
cellsize XXX
nodata_value -9999

I haven't used either way yet, that's for the student to do (and learn from)!

Re: create a raster with fielddata

JeffreySwain — Thu, 06 Oct 2011 11:00:03 GMT

The Ascii to Raster tool will work, you could add the Ascii file directly or if you decide to create points from the text file with an event layer, then you can utilize any of the interpolation tools to model the values between the the field points.