rasterio warp with rpcs example

rasterio-warp-with-rpcs-example.py

"""
RPC_DEM_SRS only used in GDAL >= 3.2.0, otherwise ignored
"""

import rasterio
import rasterio.warp
from rasterio import logging

logging.basicConfig(filename='rasterio.log', level=logging.DEBUG)  

with rasterio.Env(CPL_DEBUG='ON', PROJ_DEBUG='3') as env: # maybe still set CPL_DEBUG and PROJ_DEBUG as env var?
    with rasterio.open('rpc.tif') as src:
        arr, transform = rasterio.warp.reproject(
            rasterio.band(src, src.indexes),
            src_crs="EPSG:4326", 
            rpcs=src.rpcs, 
            dst_crs="EPSG:4326", 
            RPC_DEM="vancouver-dem-downsampled.tif", 
            RPC_DEM_SRS="EPSG:4326+5773"
        )
        with rasterio.open('rpc-warped-rasterio.tif', mode='w', transform=transform, crs="EPSG:4326", dtype=src.dtypes[0], count=arr.shape[0], height=arr.shape[1], width=arr.shape[2]) as dst:
            dst.write(arr, src.indexes)