# Export data after pre-processing
**URL:** https://forum.atmospherictoolbox.org/t/export-data-after-pre-processing/893
**Category:** HARP
**Tags:** sentinel-5p, python
**Created:** [March 17, 2025, 9:34am UTC](https://forum.atmospherictoolbox.org/t/export-data-after-pre-processing/893 "2025-03-17T09:34:35Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@jawi289o](https://forum.atmospherictoolbox.org/u/jawi289o)
#### Post date: [March 17, 2025, 9:34am UTC](https://forum.atmospherictoolbox.org/t/export-data-after-pre-processing/893/1 "2025-03-17T09:34:35Z")
I have downloaded bulk data of Sentinel-5P pollutants and now I am performing the pre-processing operations using HARP. My requirement is to save each files in tiff format for my area of interest (already have shp file). How can I do this I have tried different methods but still no luck. Can anyone guide me?
For pre-processing all the pollutants data do I need to keep anything in mind? any suggestion will be appreciated.
Thank you
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### Author:  [@sander.niemeijer](https://forum.atmospherictoolbox.org/u/sander.niemeijer)
#### Post date: [March 18, 2025, 10:31am UTC](https://forum.atmospherictoolbox.org/t/export-data-after-pre-processing/893/2 "2025-03-18T10:31:25Z")
If you want to look at long time series, you might want to use the [L3 data](https://radiantearth.github.io/stac-browser/#/external/data-portal.s5p-pal.com/api/s5p-l3) that is available from the [S5P-PAL Data Portal](https://data-portal.s5p-pal.com). This already has all the HARP pre-processing performed. You should then be able to run gdal on it, to turn the data into geotiffs.
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### Author:  [@jawi289o](https://forum.atmospherictoolbox.org/u/jawi289o)
#### Post date: [March 18, 2025, 3:34pm UTC](https://forum.atmospherictoolbox.org/t/export-data-after-pre-processing/893/3 "2025-03-18T15:34:05Z")
@sander.niemeijer thanks for responding but the issue is that I need to change the qa\_value of the pollutants.
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### Author:  [@sander.niemeijer](https://forum.atmospherictoolbox.org/u/sander.niemeijer)
#### Post date: [March 18, 2025, 4:01pm UTC](https://forum.atmospherictoolbox.org/t/export-data-after-pre-processing/893/4 "2025-03-18T16:01:43Z")
I assume you mean modification of the `qa_value` filtering and not modification of the qa values themselves. You can reproduce the L3 data yourself with revised filtering. If you look at the `history` global attribute in the L3 products you will see the harp commands that were used to generate the files. You can use those yourself, and manipulate the commands, to arrive at your own L3 products. Once you have your l3 gridded netcdf files, you can then again use gdal to convert to geotiff as I mentioned above.
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### Author:  [@jawi289o](https://forum.atmospherictoolbox.org/u/jawi289o)
#### Post date: [March 19, 2025, 9:07am UTC](https://forum.atmospherictoolbox.org/t/export-data-after-pre-processing/893/6 "2025-03-19T09:07:28Z")
@sander.niemeijer thank you so much! 🙂