Forum: SARvatore

Inverse Barometer (IB) and Atmospheric Pressure Corrections

Hi Altimetry Community,

I am a PhD student working with altimetry data and I am still relative new with the topic (which I found very interesting). Currently, I'm working on a research proyect that consist in measure the sea level variations in coastal zones using satellite altimetry, e.g, Sentinel-3A. During this time, some doubts have arisen about the resulting data received from the SARvatore platform. Some of them are listed below. Any help or advice is very welcome!. Thanks in advance.

1.- I noticed that the Inverse Barometer (IB) Correction data in the NetCDF files only appears for 1 Hz resolution but not for high resolution (20 Hz). How does the processing methodology handle the IB correction for high resolution data?, it is applied too?

2.- How the processing handle the correction caused by atmospheric pressure?. Is SAMOSA and it's variations (e,g. SAMOSA+) the only model/method used to calculate the sea level variations?

Posted by CamF on Tue 28 of July 2020 05:25 CEST
Reads: 485

Re: Inverse Barometer (IB) and Atmospheric Pressure Corrections


Hello dear User, 

 

Responding to you question: 

 

1) yes the IB correction is given only at 1 Hz. You can get it at 20 Hz by simple time-interpolation (you have the time at 1 Hz and 20 Hz in the product)

The IB correction is not supposed to be used over ocean but the DAC (DAC_Corr_1Hz)

must be used. DAC stands for Dynamic Atmospheric Correction.

The DAC is already applied in the field SLA_1Hz and SLA_20Hz. 

Pay attention, you must apply to SLA the sea state bias (SSB) correction which you find in the product. SSB is not applied by default.

 

2)  by default DAC is used which is considered the most accurate one.

and yes SAMOSA/SAMOSA+ are the only methods used to computed the SLA so far

(others are coming soon)

 

All best

 

Salvatore Dinardo

 

> Hi Altimetry Community,
>
> I am a PhD student working with altimetry data and I am still relative new with the topic (which I found very interesting). Currently, I'm working on a research proyect that consist in measure the sea level variations in coastal zones using satellite altimetry, e.g, Sentinel-3A. During this time, some doubts have arisen about the resulting data received from the SARvatore platform. Some of them are listed below. Any help or advice is very welcome!. Thanks in advance.
>
> 1.- I noticed that the Inverse Barometer (IB) Correction data in the NetCDF files only appears for 1 Hz resolution but not for high resolution (20 Hz). How does the processing methodology handle the IB correction for high resolution data?, it is applied too?
>
> 2.- How the processing handle the correction caused by atmospheric pressure?. Is SAMOSA and it's variations (e,g. SAMOSA+) the only model/method used to calculate the sea level variations?

Posted by Salvatore.Dinardo on Tue 28 of July 2020 11:43 CEST
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Re: Re: Inverse Barometer (IB) and Atmospheric Pressure Corrections


Dear Salvatore Dinardo,

 

Thank you for your prompt response, which has been a great help. Your answers have been very helpful to understand concepts that are new for me, and yes, I have applied the SSB to SLA in order to restore the sea level varitions with great results.

 

Kind Regards,

-Carlos M.

 

>
> Hello dear User, 
>
>  
>
> Responding to you question: 
>
>  
>
> 1) yes the IB correction is given only at 1 Hz. You can get it at 20 Hz by simple time-interpolation (you have the time at 1 Hz and 20 Hz in the product)
>
> The IB correction is not supposed to be used over ocean but the DAC (DAC_Corr_1Hz)
>
> must be used. DAC stands for Dynamic Atmospheric Correction.
>
> The DAC is already applied in the field SLA_1Hz and SLA_20Hz. 
>
> Pay attention, you must apply to SLA the sea state bias (SSB) correction which you find in the product. SSB is not applied by default.
>
>  
>
> 2)  by default DAC is used which is considered the most accurate one.
>
> and yes SAMOSA/SAMOSA+ are the only methods used to computed the SLA so far
>
> (others are coming soon)
>
>  
>
> All best
>
>  
>
> Salvatore Dinardo
>
>  
>
> > Hi Altimetry Community,
> >
> > I am a PhD student working with altimetry data and I am still relative new with the topic (which I found very interesting). Currently, I'm working on a research proyect that consist in measure the sea level variations in coastal zones using satellite altimetry, e.g, Sentinel-3A. During this time, some doubts have arisen about the resulting data received from the SARvatore platform. Some of them are listed below. Any help or advice is very welcome!. Thanks in advance.
> >
> > 1.- I noticed that the Inverse Barometer (IB) Correction data in the NetCDF files only appears for 1 Hz resolution but not for high resolution (20 Hz). How does the processing methodology handle the IB correction for high resolution data?, it is applied too?
> >
> > 2.- How the processing handle the correction caused by atmospheric pressure?. Is SAMOSA and it's variations (e,g. SAMOSA+) the only model/method used to calculate the sea level variations?

Posted by CamF on Tue 28 of July 2020 22:31 CEST
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