# Q transform vs spectrogram

**URL:** <https://ask.igwn.org/t/q-transform-vs-spectrogram/1034>\
**Category:** Open Data Workshop\
**Created:** [May 9, 2024, 11:59am UTC](https://ask.igwn.org/t/q-transform-vs-spectrogram/1034 "2024-05-09T11:59:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![arata](https://avatars.discourse-cdn.com/v4/letter/a/e79b87/32.png) [@arata](https://ask.igwn.org/u/arata)\
**Post date:** [May 9, 2024, 11:59am UTC](https://ask.igwn.org/t/q-transform-vs-spectrogram/1034/1 "2024-05-09T11:59:32Z")

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Can anyone explain me why we are doing Q-Transform to get time-frequency plot, if we can also get it using spectrogram. I don’t want to go into the details, just an overview answer.

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**Author:** ![BarryG](https://avatars.discourse-cdn.com/v4/letter/b/9f8e36/32.png) [@BarryG](https://ask.igwn.org/u/BarryG)\
**Post date:** [May 10, 2024, 6:45am UTC](https://ask.igwn.org/t/q-transform-vs-spectrogram/1034/2 "2024-05-10T06:45:38Z")

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Hi Arata:  
The answer to this question is based on what you want to observe. Different transforms are sensitive to different types of data. I believe not all people are using q-transform, for example in the burst signal data analysis they also choose some other transforms.

Q-transform is a trading-off of different time-frequency resolutions. In low frequency one will have higher resolution in time but not so good in frequency. When frequency increases, the resolution of the time domain will decrease (easy to understand, since the signal at high frequency has a lower period) for a higher frequency resolution.  
This method works for many data, such as glitches, chirp signal,s and so on.  
Spectrogram will work in some scenarios as well, but the time-frequency resolution is fixed which means it might not capture a signal across a much wider frequency band well

Good luck

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**Author:** ![arata314](https://avatars.discourse-cdn.com/v4/letter/a/b3f665/32.png) [@arata314](https://ask.igwn.org/u/arata314)\
**Post date:** [May 10, 2024, 4:32pm UTC](https://ask.igwn.org/t/q-transform-vs-spectrogram/1034/3 "2024-05-10T16:32:09Z")

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Ahh Thanks, I understood now.