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clariusdev / raw

Programs to Read and Process Raw Data from Clarius Devices
https://www.clarius.com
BSD 3-Clause "New" or "Revised" License
13 stars 5 forks source link

Sampling Frequency #23

Closed DandelionB closed 1 month ago

DandelionB commented 7 months ago

Dear Kris,

We are using C3HD and have a problem regarding its sampling frequency for the RF data.

The RF data recorded at imaging depths above 4 cm sometimes had a sampling frequency of 15 MHz or 20 MHz while we expect a constant frequency of 15 MHz as in the posted info: "At depths < 2cm, 60MHz sampling is applied; at 2 - 4cm, 30MHz sampling is applied; at depths > 4cm, 15 MHz sampling is applied".

For example, at 6 cm, we got 1568 data points/line -> sampling frequency was 20 MHz, not 15 MHz. Sometimes, at 6 cm, we got 1168 data points/line -> sample frequency was 15 MHz as expected.

So is it true that the sampling frequency from Clarius can vary out of 60/30/15 MHz and inconsistently varies even at the same depth?

Thank you very much!

clariusk commented 7 months ago

yes, it can vary, latest software uses transmit frequency to adjust the RF sampling rate, not depth anymore