I'm trying to do a supervised classification in ArcGIS Pro that will allow me to find Tar and Gravel rooftops in Miami.

I have Landsat data but just wondering if there is imagery out there with better spatial resolution that might work better?


2 Answers 2


Sentinel-2 has a higher spatial resolution (10x10 m in VIS+NIR) compared with Landsat series (30x30 m, 15 m in panchromatic), so your results must be more accurate. Also, is a free to use sensor.

Here you can compare spectral resolutions:

enter image description here

  • I'm a bit new to this. I know spectral resolution is pretty important for image classification. Does the Sentinel 2 have as good a spectral resolution? Having a bit of trouble reading the image you posted. I know Landsat 8 has 8 bands. From what I've read Sentinel only has about half that.
    – Beau
    Commented Aug 1, 2018 at 16:35
  • @Beau Sentinel-2 has some bands in 10m, 20m and 60m. In 10m resolution, has RGB + NIR; in 20 m, has far red (a.k.a. red edge) + NIR + SWIR; and in 60 m, has some bands to retrieve quality data.
    – aldo_tapia
    Commented Aug 1, 2018 at 16:37
  • Do you think RGB+NIR will be good enough for ArcPro to tell the difference between Tar and Gravel rooftops and everything else or that I may need more bands?
    – Beau
    Commented Aug 1, 2018 at 16:41
  • Spectral profiles of this kind of material are almost a line, so you should be ok. But 10 m isn't enough to compute differences on small buildings but is the better spatial resoution found on free imagery
    – aldo_tapia
    Commented Aug 1, 2018 at 16:49
  • Thanks for all the help! All the rooftops I'm looking at will be industrial and so should be a bit larger. Also they tend to be all one material. I'm hoping to get at least a sample of what should be Tar and Gravel, then do some ground truthing with Google Earth.
    – Beau
    Commented Aug 1, 2018 at 16:52

Within the United States there is the National Agriculture Imagery Program (NAIP), which has 4-band imagery available every few years at 1m resolution. If you're using an ESRI product, it is very simple to load/analyze/export this data directly from the United States Department of Agriculture (USDA) Aerial Photography Field Office (APFO) via their Image Server: https://gis.apfo.usda.gov/arcgis/services

Note: This isn't a link that will open in a browser. You must add a new GIS Server in ArcGIS and point it to this address.

I have had great success with supervised classification between rocks and asphalt using NAIP and other 4-band imagery in the past.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.