[Qgis-user] NDVI resolution

[Fielding, Eric J (US 329A)]

Neels,

The Worldview-3 satellite has different resolutions in the different bands. There is a panchromatic band that has 31 cm resolution, but the multispectral bands have 124 cm (1.2 m) resolution. You are probably seeing objects with the panchromatic band, but NDVI has to use the coarser multispectral bands.

Some of the Worldview data products use the panchromatic band to "sharpen" the multispectral images, but the multispectral data is fundamentally four times coarser than the panchromatic bands. If the multispectral bands have been resampled (interpolated) to the 31 cm pixel size to match the panchromatic band, they will be fuzzier.

++Eric

    Date: Fri, 7 May 2021 18:27:39 +0000
    From: Neels Brink <Neels.Brink at incomargroup.com>

    Yes, the raster calculator, and the extent (resolution, nr of  pixels, everything)  of the output file matches that of the two input bands. What is interesting is that I noted that the boundaries of some man-made objects  do no show this fuzziness:

    [cid:image006.jpg at 01D7437F.67F906C0]



    From: Nicolas Cadieux <njacadieux.gitlab at gmail.com>
    Sent: Friday, May 7, 2021 6:27 PM
    To: Neels Brink <Neels.Brink at incomargroup.com>
    Subject: Re: [Qgis-user] NDVI resolution

    Hi,
    Did you use the raster calculator?  If so, did you select the proper extent and rows and columns in the output files?

    Le 7 mai 2021 ? 11:56, Neels Brink <Neels.Brink at incomargroup.com<mailto:Neels.Brink at incomargroup.com>> a ?crit :
    ?
    I created an NDVI in QGis from Worldview -3 bands. However, the NDVI looks ?fuzzy?, or at lower resolution than the original bands. I tried to find a flag or setting which causes this but do not see something like it. What could be the reason for this appearance of the NDVI?