TROPOMI L2 to L3 with HARP qa_value error

HARP
1

Hello,
I am having an issue with the HARP conversion program, which won’t let me convert the “qa_value” of TROPOMI products from Level-2 to Level-3. Could someone assist me in finding a solution?

Some options I am exploring are:

  • Determine what values and equations go into the “qa_value” dataset. Compile parameters into a new dataset that is converted to L3 and then calculate qa_value of each pixel… Issue: Many parameters to process, lower efficiency
  • If the qa_value conversion is not supported due to the internal use of bin_spatial, then modify/replace the bin_spatial component with my own function allowing for qa_value L2 to L3 conversion … (ongoing, not yet sure how to execute)

Thank you sincerely for you thoughts and input.

2

You really shouldn’t try to average the qa_value. Some of it is based on the processing quality flags, and those just can’t be averaged.

The qa_value is meant to filter the data. So you should filter the data at the beginning, before you call bin_spatial.

If you want to look at a quality measure after gridding, then you should look at the uncertainty, which is something that HARP propagates when you regrid the data.

In addition, you could still look at quality influence variables, such as cloud fraction, albedo, solar angles, etc. Those variables will also get regridded. But just don’t try to use the qa_value for that.