How to calculate the percentage of green spaces in remote sensing image using erdas imagine?
You can use either ENVI or Erdas. You can even use ArcGIS though it is less efficient for this type of process. I think it is easier to just point you to a website:
http://watertohoku-tutorials.blogspot.com/2012/06/ndvi-calculation-in-erdas.html
After you calculate the NDVI map, anything over 0.5 is probably vegetation (probably over 0.3 too). Anything that is negative is likely water. Your urban areas should show up in the 0-0.3 range. You may have to play around with the threshold values for your area (different vegetation has different NDVI values). FYI bare soil will look like urban areas so I am assuming you are not working with agricultural fields in your image (or at least if you are it is mid-way through the planting season).
Are you just interested in just separating an urban area from vegetation? If so you could create a NDVI map and use a threshold to separate your classes.
Yes , i want to separate it.
But do you mean usiing arcgis or erdas ???
You can use either ENVI or Erdas. You can even use ArcGIS though it is less efficient for this type of process. I think it is easier to just point you to a website:
http://watertohoku-tutorials.blogspot.com/2012/06/ndvi-calculation-in-erdas.html
After you calculate the NDVI map, anything over 0.5 is probably vegetation (probably over 0.3 too). Anything that is negative is likely water. Your urban areas should show up in the 0-0.3 range. You may have to play around with the threshold values for your area (different vegetation has different NDVI values). FYI bare soil will look like urban areas so I am assuming you are not working with agricultural fields in your image (or at least if you are it is mid-way through the planting season).
I am agree with Anthony, you can use NDVI, but maybe other indexes such as SAVIو WDVI ,... also useful, depend to the condition of your area.
- Badges
- Science topic
- Similar topics
- Geoscience
- Remote Sensing