How to mosaic images with different CRS with rasterio

Question

I am doing mosaicing of 14 raster images (.img format) to completely cover a province.see original spatial location of separately opened tiles(). Mosiac operation is completed but 4 tiles are mosiaced on wrong spatial location. whereas other 10 tiles are mosiaced accurately (). when i am opening separate files all files are getting opened at their origina spatial location. please help me to resolve this issue. I am using this code for mosaicing of 14 raster images.

import rasterio
from rasterio.merge import merge
from rasterio.plot import show
import glob
import os

dirpath = r"path"
outpath = r"outpath\Mosiac.tif"

search_criteria = "*.img"

q = os.path.join(dirpath, search_criteria)
print (q)
img_fps = glob.glob(q)
img_fps

src_files_to_mosiac = []

for sim in img_fps:
src = rasterio.open(sim)
src_files_to_mosiac.append(src)

src_files_to_mosiac

mos, out_trans = merge(src_files_to_mosiac)

show(mos, cmap='terrain')

with rasterio.open(outpath,"w", driver ='Gtiff',count=3,
            height= mos.shape[1],
            width= mos.shape[2],
            transform= out_trans,
            crs= src.crs,
            dtype= src.dtypes[0]) as dest:
dest.write(mos)

Answer 1

I got a solution. Converted all the files into lat long wgs84 CRS. By using the code given below-

import numpy as np
import rasterio
from rasterio.warp import calculate_default_transform, reproject, Resampling

dst_crs = 'EPSG:4326'

with rasterio.open('path/test.tif') as src:
    transform, width, height = calculate_default_transform(
        src.crs, dst_crs, src.width, src.height, *src.bounds)
    kwargs = src.meta.copy()
    kwargs.update({
        'crs': dst_crs,
        'transform': transform,
        'width': width,
        'height': height
    })

    with rasterio.open('path/test_wgs84.tif', 'w', **kwargs) as dst:
        for i in range(1, src.count + 1):
            reproject(
                source=rasterio.band(src, i),
                destination=rasterio.band(dst, i),
                src_transform=src.transform,
                src_crs=src.crs,
                dst_transform=transform,
                dst_crs=dst_crs,
                resampling=Resampling.nearest)

This removed the barrier of different UTM zones and then using the code given in my question, mosaic image was generated. Actually this is quite obvious approach but i was trying to perform it in an automated manner. Converted above mentioned code into function, applied the function on all images through looping and got succeed.

Thanks everyone.