title: How can I find the pixel-wise maximum of multiple rasters?
body: <p>I have hundreds of rasters with same resolution and extent. It's a time series and each raster represent one point of time. </p>
  
  <p>I know how to find the absolute maximum value in a raster.</p>
  
  <p>But how can I find the maximum value in each cell in the entire time series of rasters?</p>
  
  <p>If a1,a2,......a1000 are rasters, I want to create a raster x where each pixel is the maximum of all corresponding pixels of a1-a1000.</p>