# HARP operations

**URL:** https://forum.atmospherictoolbox.org/t/harp-operations/934
**Category:** HARP
**Created:** [December 4, 2025, 1:18pm UTC](https://forum.atmospherictoolbox.org/t/harp-operations/934 "2025-12-04T13:18:52Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![panfount](https://forum.atmospherictoolbox.org/letter_avatar_proxy/v4/letter/p/ebca7d/32.png) [@panfount](https://forum.atmospherictoolbox.org/u/panfount)
#### Post date: [December 4, 2025, 1:18pm UTC](https://forum.atmospherictoolbox.org/t/harp-operations/934/1 "2025-12-04T13:18:52Z")

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Hello!!

I am using harp in the S5P/TROPOMI trajectory files, in order to keep from each file the data that are “inside” a circle area. To do so, I use the following command in the harp operations:

point\_distance({lat}, {lon}, {point\_val}[km])

where lat and lon are the latitude and the longitude of a specific point on Earth, respectively, and point\_val is the circle radius.

Using harp, is there a way that I can take a domain box (e.g. square domain box), instead of a circle??

Thank you in advance!!

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### Author: ![sander.niemeijer](https://forum.atmospherictoolbox.org/user_avatar/forum.atmospherictoolbox.org/sander.niemeijer/32/5_2.png) [@sander.niemeijer](https://forum.atmospherictoolbox.org/u/sander.niemeijer)
#### Post date: [December 4, 2025, 4:14pm UTC](https://forum.atmospherictoolbox.org/t/harp-operations/934/2 "2025-12-04T16:14:28Z")

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Yes. This is definitely possible.

The easiest and also fastest to execute by HARP is to provide filters on latitude and longitude. e.g. `latitude>=50;latitude<60;longitude>=0;longitude<=20`

You can also extract all satellite pixels within a bounding polygon using the `point_in_area` operation. e.g. `point_in_area((38.295,38.104,38.347,38.815,39.979,38.518),(22.700,22.642,19.797,16.969,17.320,22.195))`.

There are also other types of geolocation filters that you can use. More information on this can be found in the [documentation](https://stcorp.github.io/harp/doc/html/operations.html#function-call).