orthorectify a geospatial raster

dem.xml

<GDAL_WMS>
  <service name="TMS">
    <ServerUrl>https://s3.amazonaws.com/elevation-tiles-prod/geotiff/${z}/${x}/${y}.tif</ServerUrl>
  </service>
  <DataWindow>
    <UpperLeftX>-20037508.34</UpperLeftX>
    <UpperLeftY>20037508.34</UpperLeftY>
    <LowerRightX>20037508.34</LowerRightX>
    <LowerRightY>-20037508.34</LowerRightY>
    <TileLevel>14</TileLevel>
    <YOrigin>top</YOrigin>
  </DataWindow>
  <Projection>EPSG:3857</Projection>
  <BlockSizeX>512</BlockSizeX>
  <BlockSizeY>512</BlockSizeY>
  <BandsCount>1</BandsCount>
  <DataType>Int16</DataType>
  <ZeroBLockHttpCodes>403,404</ZeroBLockHttpCodes>
  <DataValues>
    <NoData>-32768</NoData>
  </DataValues>
  <Cache>
    <Extension>.tif</Extension>
  </Cache>
</GDAL_WMS>

orthorectify.sh

gdalwarp \
  --debug on \
  -of COG -co BLOCKSIZE=64 -co COMPRESS=DEFLATE \
  -multi \
  --config GDAL_CACHEMAX 15% -wm 15% -co NUM_THREADS=ALL_CPUS -wo NUM_THREADS=1 \
  -t_srs EPSG:4326 -et 0 -rpc -to RPC_DEM=dem.xml \
  -overwrite -srcnodata 0 -dstnodata 0 \
  source.tiff output.tiff