Google Earth Engine: reproject images to the same projection

Question

Below, I have clipped the same region from 2 google earth images. However, the two clips are at different projections (the crs argument in reproject determines the projection). The reason I am reprojecting is to decrease the resolution of the images, via the scale argument, so that they can be imported with sampleRectangle. How would I clip the images at the same projection such that they overlap?

import ee
import matplotlib.pyplot as plt
from matplotlib.pyplot import imshow
import numpy as np

# Load images
pH = ee.Image("OpenLandMap/SOL/SOL_PH-H2O_USDA-4C1A2A_M/v02")
AAFC = ee.ImageCollection('AAFC/ACI')
AAFC = AAFC.filter(ee.Filter.date('2016-01-01', '2016-12-31')).first()


# Get geometry/polygon of interest
geometry = CAR.getInfo()['features'][15]['geometry']['coordinates']
region = ee.Geometry.Polygon(geometry)


# Clip AAFC and plot
AAFC_crs = AAFC.clip(region).projection().wkt()

AAFC_region = AAFC.clip(region)
AAFC_region = AAFC_region.resample('bilinear').reproject(crs=AAFC_crs, scale=1000)
AAFC_img = AAFC_region.sampleRectangle(defaultValue=0)
AAFC_img = np.array(AAFC_img.getInfo()['properties']['landcover'])
AAFC_img = AAFC_img.reshape(len(AAFC_img), -1)

plt.imshow(AAFC_img)
plt.colorbar()
plt.show()


# Clip pH and plot
pH_crs = pH.clip(region).projection().wkt()

pH_region = pH.clip(region)
pH_region = pH_region.resample('bilinear').reproject(crs=pH_crs, scale=1000)
pH_img = pH_region.sampleRectangle(defaultValue=0)
pH_img = np.array(pH_img.getInfo()['properties']['b30'])
pH_img = pH_img.reshape(len(pH_img), -1)

plt.imshow(pH_img)
plt.colorbar()
plt.show()

Answer 1

You should be able to set a common crs in both reproject() calls. Since I don't know where exactly your study area is you can use a global coordinate reference system like WGS84 with the EPSG Code 4326.

Alternatively you can look up the UTM Zone of your study area and get a more local EPSG code.

# Clip AAFC and plot
AAFC_region = AAFC.clip(region)
AAFC_region = AAFC_region.resample('bilinear').reproject(crs='EPSG:4326', scale=1000)

# Clip pH and plot

pH_region = pH.clip(region)
pH_region = pH_region.resample('bilinear').reproject(crs='EPSG:4326', scale=1000)