Why are raster datasets so much bigger than vector data?
Raster datasets can become potentially very large because they record values for each cell in an image. As resolution increases, the size of the cell decreases. But this comes at a cost for speed of processing and data storage. It’s not always straight-forward which spatial data type you should use for your maps.
What’s the difference between discrete and continuous raster data?
Raster data models consist of 2 categories – discrete and continuous. Discrete rasters have distinct themes or categories. For example, one grid cell represents a land cover class or a soil type. In a discrete raster land cover/use map, you can distinguish each thematic class.
What’s the difference between a raster and a satellite image?
Each pixel value in a satellite image has a red, green and blue value. Alternatively, each value in an elevation map represents a specific height. It could represent anything from rainfall to land cover. Raster models are useful for storing data that varies continuously. For example, elevation surfaces, temperature and lead contamination.
Why do rasters and vectors not line up in ArcMap?
If datum are in different coordinate systems, there is a possibility that these coordinate systems are not directly compatible and a mis-alignment may result. If this is the case, the following warning may appear when adding raster or vectors to ArcMap. Set a Transformation to fix the mis-alignment.
Why do you need a spatial reference system for raster?
You want to minimize this to maintain the best image and data quality. When you define a spatial reference system for a raster dataset, you are defining the projection used to store the data. This has a direct effect on the cells, as they are permanently resampled to fit this projection.
Is there a working version of ArcGIS for raster?
A working version of ArcGIS with the Spatial Analyst Toolbar enabled (check via Customize –> Extensions –> Check Spatial Analyst) Two raster datasets (you can download those files according to the original post) 7zip or any other unzipper for the example files