Raster and Floating Point GeoTIFFs: What is the difference?NASA Earth Observations (NEO)on December 23, 2020 at 10:59 pm
When you are considering which format to download for a NEO image, there are two GeoTIFF format options: GeoTIFF (raster) and GeoTIFF (floating point). This can be confusing at first. Let’s take a look at both examples using the Chlorophyll Concentration dataset to distinguish the two formats.
Here is a screenshot showing the Downloads box with an arrow pointing to where you can select either GeoTiff format and a circle around where the raw data is available for download.
This is the Aqua/ MODIS Chlorophyll Concentration GeoTIFF (floating point) image for the month of October 2020.
The image above is what downloads when you select GeoTIFF (floating point). This is a floating-point image file where each cell has a number with a decimal (ex. 1.1111). We call this format “data-like” for our purposes because it has been scaled and resampled as part of the processing of the original source data for NEO and the files are simplifications of the original data. Keep this in mind when you are using NEO imagery for analysis—our datasets should not be used for scientific research because they were not calibrated to the precision needed for scientific analysis. If you want to do your own processing for scientific research, choose the “Download Raw Data” option located in the Downloads box.
This is the Aqua/ MODIS Chlorophyll Concentration GeoTIFF (raster) image for the month of October 2020.
To simplify even further, the GeoTIFF (raster) above is an 8-bit color image. The values are stored as 8 bit grayscale and the color table is applied on-the-fly based on those values.
If you have any additional questions or need further clarification, please email us through the “Contact Us” button below.
NASA Earth Observations (NEO)Learn about the difference between the floating point and raster GeoTIFF download options for each dataset.