Calibration with S1A SLC data - VH is OK but VV fails

I am trying to run radiometric calibration on S1A SLC data. The exact image is


My process to this point is:

Orbital Correction --> Deburst

When I run the calibration on this product (I am trying to produce b0 values to be terrain flattened in the next step), the results for VH b0 look ok, but the VV b0 image is blank - all the values are zero or nodata, I’m not sure which.

Does anyone know what my issue may be, or has anyone else experienced this problem?

I am using the latest version of SNAP for linux, on a machine with 4 cores and 16gb RAM.

Many thanks,


Indeed, something seems to go wrong when calibrating after debursting. It works fine if you calibrate first and then deburst.
I’ve created an issue for this.


Calibration should be applied before deburst for IW SLC products. An exception is now thrown to notify the user if he/she tries to apply calibration to a debursted IW SLC product.

“Calibration should be applied before deburst” error received as well when trying to calibrate S1 SM (Stripmap) SLC products, e.g. S1A_S6_SLC__1SDV_20180814T055228_20180814T055247_023238_02869C_5F72.
SNAP 6.0
S1TBX 6.0.4

Thanks I’ve just fixed that. It’ll be available in the next module update 6.0.5

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Hi Lveci,

Thanks for the info.