When you download a Surface Reflectance (SR) asset from Planet, you may notice that the associated XML metadata file contains the following line: <ps:atmosphericCorrectionApplied>false</ps:atmosphericCorrectionApplied>

This can be confusing, as the filename specifically indicates it is an SR product.

The Reason

The XML metadata file delivered with your order refers to the Basic Analytic asset (the raw data before orthorectification and atmospheric correction).

Planet delivers this standard XML file even when you order a Surface Reflectance product. Therefore, the "false" flag in the XML indicates that the Basic asset was not corrected, but it does not apply to the SR GeoTIFF itself.

How to Verify Atmospheric Correction

If you need to confirm that atmospheric corrections have been applied to your image, you should check the GeoTIFF header rather than the XML file.

Method 1: Using QGIS

1. Open your SR GeoTIFF in QGIS.

2. Right-click the layer and select Properties.

3. Navigate to the Information or Metadata tab.

4. Look for the header information where atmospheric parameters are listed.

Method 2: Using Python (Rasterio)

Associated metadata describing inputs to the correction is included in the TIFFTAG_IMAGEDESCRIPTION header as a JSON string. You can extract this using the following script:

import rasterio
import json

# Replace with your specific SR filename
filename = rasterio.open('20210913_211131_ssc15_u0001_analytic_SR.tif')

# Extract the Image Description tags
tags = filename.tags()['TIFFTAG_IMAGEDESCRIPTION']
jtags = json.loads(tags)

# Access atmospheric correction inputs
atm_inputs = jtags['atmospheric_correction']
print("Atmospheric Correction Metadata:", json.dumps(atm_inputs, indent=4))

Summary

• Check the Filename: If the asset filename includes _SR, it is a Surface Reflectance product and has been atmospherically corrected.

• Ignore the XML Flag: The <ps:atmosphericCorrectionApplied> tag in the XML pertains only to the uncorrected Basic Analytic asset.

• Verify via Header: For technical verification, always refer to the metadata embedded directly in the GeoTIFF header.

For more information, please see Extracting Inputs to Atmospheric Correction.