microsoft / microsoft/PlanetaryComputerExamples
Question: landsat-c2-l2 scaling & NDVI
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- Jupyter Notebook
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Description
Hi,
I was going through the landsat-c2-example.ipynb notebook and noticed that the NDVI is calculated directly from the red and nir08 bands as loaded via odc.stac - without applying the documented scale and offset.
My understanding of odc.stac is that it does not apply scaling by default, so the computation as in the example notebook seems to be using the raw integer DNs. Doesn't this bias the NDVI? Is there a specific reason why the example computes NDVI on the unscaled data - or have I misunderstood anything?
Thank you for providing and maintaining these examples, they've been super helpful for getting familiar with MPC!
Best
Maike
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Research direction
Open datasets/landsat-c2/landsat-c2-example.ipynb and review how odc.stac loads the red and nir08 bands before the NDVI calculation. Compare that calculation with the documented scale and offset, then clarify the reason for the current behavior or update the example so the notebook's NDVI computation is correct.
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Assessment
- Tech stack
- jupyter-notebook
- Domain
- data
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100