title: How to calculate Tasseled Cap Transformation for Sentinel-2 images (from GEE) with different resolution of bands in R?
body: <p>I downloaded Sentinel-2 stack from the Google Earth Engine. For the export I used resolution (<code>scale: 10</code>), while some bands there should have resolution 20 m (SWIR) or 60 m(e.g. Cirrus):</p>
  
  <pre><code>Export.image.toDrive({
    image: exportImgSentinel, 
    description: 'Sentinel', 
    folder: 'Sentinel', 
    fileNamePrefix: 'Sentinel', 
    region: region, 
    scale: 10, 
    crs: 'EPSG:4326'
  });
  </code></pre>
  
  <p>Opening it as a RasterStack in R, I checked resolution of the stack:</p>
  
  <pre><code>res(Sentinel_weird_1)
  [1] 8.983153e-05 8.983153e-05
  </code></pre>
  
  <p><strong>And the same for each separated band within</strong>. OK, I tried to make some Tasseled Cap bands, typing formula using respective bands. I have got raster with only 2 different values, that is apparently wrong.
  What to do in such cases? Should I:</p>
  
  <ul>
  <li><p>download separate bands from GEE with different resolution, and then <code>disaggregate</code> in R bands with 20 or 60 m resolution to the 10 m?</p></li>
  <li><p>or it will not work, since some data accuracy from 20-60 m resolution will be lost, and I should <code>aggregate</code> bands to the worst (60 m) resolution? That is, I can only make TCT maps with such bad resolution from Sentinel-2 images?</p></li>
  </ul>
  
  <p>For Landsat data everything is clear. <code>res</code> function shows 30 m scale resolution. But I wanna have better map with 10 m resolution. Can I?</p>