Negative Elevation Using SAR Wizard

Hello everyone,
I would like to ask about SAR Mosaic using SAR Wizard.
My processes follow this instruction:
And after that , I export to TIFF file. But the elevation is negative.
Please help me to solve it.

And a sub-question is : Could I use graph builder to mosaic different orbit line?

Thank you so much.
Best regards.

what data are you using? Maybe the SAR Mosaic wizard is not the best choice for elevation data.

Yes, I’m processing Sentinel 1 by Snap. Now I’m trying to use batch processing to mosaic.
May I get your advice?

Did the S1 elevation have negative elevations before mosaicing?

I think the easier choice is to apply terrain correction to all outputs and use the “classic” mosaic operator instead.

Can I ask why you want to batch process such a task? Doesn’t seem logic to me.

I have to use batch process because I need to repeat mosaic in several season for my job.

You mean I should do : Terrain Correction-> SAR-mosaic, is it right?

yes. But I am still a bit concerned that elevations from Sentinel-1 will bring you usable results. There are many error sources and you will lose control on the quality of the intermediate products with batch processing.
In my opinion, DEM generation from SAR data is something which should not be fully automated, because you have to adjust parameters, control the intermediate products, check for feasibility…

Do the interferograms look alright?

I have a little bit of understanding.
I will try to mosaic manually if negative value still exists.
Thank you so much.