# How to get the time
**URL:** https://forum.atmospherictoolbox.org/t/how-to-get-the-time/734
**Category:** CODA
**Tags:** python
**Created:** [January 6, 2024, 6:09am UTC](https://forum.atmospherictoolbox.org/t/how-to-get-the-time/734 "2024-01-06T06:09:27Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@chen](https://forum.atmospherictoolbox.org/u/chen)
#### Post date: [January 6, 2024, 6:09am UTC](https://forum.atmospherictoolbox.org/t/how-to-get-the-time/734/1 "2024-01-06T06:09:28Z")
My dear I utilize coda to read the data of L2B, there is no specific time, what should I do?
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### Author:  [@sander.niemeijer](https://forum.atmospherictoolbox.org/u/sander.niemeijer)
#### Post date: [January 8, 2024, 10:28am UTC](https://forum.atmospherictoolbox.org/t/how-to-get-the-time/734/2 "2024-01-08T10:28:12Z")
I assume you mean AEOLUS L2B?
The format is unfortunately a bit complex, since you have to link the `rayleigh_profile` dataset (which has the time information) to the `rayleigh_geolocation` and `rayleigh_hloswind` dataset by means of the `wind_result_id_number`.
It might be easier to read the data using HARP where all this work is already done for you.
You can check the [mapping description of AEOLUS L2B in the HARP documentation](http://stcorp.github.io/harp/doc/html/ingestions/AEOLUS_L2B_Rayleigh.html#mapping-description) to see how HARP reads the data. If you don’t want to use HARP, you can use this as guideline on how to read the data with CODA.
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### Author:  [@chen](https://forum.atmospherictoolbox.org/u/chen)
#### Post date: [January 9, 2024, 12:19pm UTC](https://forum.atmospherictoolbox.org/t/how-to-get-the-time/734/3 "2024-01-09T12:19:36Z")
Dear sander.niemeijer
Thank you very much for your answer, it may be that I was not clear before, I am now reading the data of AEOLUS L2B and using the coda environment. But I’m running into some questions, first, how do I read the wind result HLOS error in the data, and the other question is, how do I filter the latitude and longitude range? I have a site of latitude and longitude, like filtering the data closest to him when a satellite transits.
We look forward to hearing from you
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### Author:  [@sander.niemeijer](https://forum.atmospherictoolbox.org/u/sander.niemeijer)
#### Post date: [January 9, 2024, 1:03pm UTC](https://forum.atmospherictoolbox.org/t/how-to-get-the-time/734/4 "2024-01-09T13:03:26Z")
What error field are you specifically talking about? I don’t see an error in the `hloswind` datasets. You can find the coda format definition for the L2B [here](https://stcorp.github.io/codadef-documentation/AEOLUS/products/ALD_U_N_2B_03_95.html).
Filtering on latitude/longitude can be done when using HARP, but only as a filter (i.e. finding _all_ satellite measurements within some range). There is no direct way to only keep the ‘closest’ measurement.
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### Author:  [@chen](https://forum.atmospherictoolbox.org/u/chen)
#### Post date: [January 9, 2024, 1:41pm UTC](https://forum.atmospherictoolbox.org/t/how-to-get-the-time/734/5 "2024-01-09T13:41:37Z")
Dear sander.niemeijer
Thank you very much for your answer，Is there a specific case for HARP about aeolusl2b how to read
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### Author:  [@sander.niemeijer](https://forum.atmospherictoolbox.org/u/sander.niemeijer)
#### Post date: [January 9, 2024, 1:56pm UTC](https://forum.atmospherictoolbox.org/t/how-to-get-the-time/734/6 "2024-01-09T13:56:13Z")
Not really, but you can start with a simple import (assuming you use python):
```auto
import harp
product = harp.import_product("/path/to/your/AEOLUS-L2-product")
```
Since AEOLUS data is relatively small, you might not even need to pre-filter the data with HARP, but directly do your operations in Python on the imported data product.
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### Author:  [@chen](https://forum.atmospherictoolbox.org/u/chen)
#### Post date: [January 9, 2024, 2:14pm UTC](https://forum.atmospherictoolbox.org/t/how-to-get-the-time/734/7 "2024-01-09T14:14:17Z")
Dear sander.niemeijer
Thank you very much for your answer . I’ll give it a try.
Thank you very much again for your reply.
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### Author:  [@chen](https://forum.atmospherictoolbox.org/u/chen)
#### Post date: [January 16, 2024, 6:49am UTC](https://forum.atmospherictoolbox.org/t/how-to-get-the-time/734/8 "2024-01-16T06:49:47Z")
Dear
I am now using harp to read the wind speed at different heights of AeolusL2B, and now I encounter a problem, that is, after reading the harp’s instruction manual, I am still confused, I don’t know how to use the code to implement it, and how to filter the range of latitude and longitude?