WHY 'SMOS L2SM Auxiliary Data Files (ADFs)' DBL data can not open

Hi there,

Anyone know why the ‘SMOS L2SM Auxiliary Data Files (ADFs)’ DBL file (e.g. SM_TEST_AUX_DFFSOI_20050101T000000_20500101T000000_001_002_9.DBL) can not be opened? Saying ‘No appropriate product reader found’

Also the same problem with the EEF file (e.g., SM_TEST_AUX_CNFSMD_20050101T000000_20500101T000000_001_015_9.EEF)

When installing SNAP, did you select to install the SMOS toolbox?

Hello, thank you for reply!!

Yes, I ticked all the square with an option

In fact, among all the auxiliary files, only ‘dffg_lai’, ‘dgg_cur_flood’, ‘dgg_cur_rfi’ and ‘ecmwf’ can open

I don’t know why … and the ‘aux_data’ was downloaded from ARRAY website, which saying to be the updated ADFs

May I have your email and send you one of the files and let you have a try to open it???

Good morning,

the files you listed in your first post can not be opened by the SMOS-Box because these are unsupported SMOS data types. The list of supported data types can be found in the SMOS-Box help section of the toolbox.

Sorry for that,


Dear Tom,

Thank you for your reply, from SNAP help the supported data says like this:

And, from the ADFs that I got, they are like this:

Also, they can be opened in SMOS viewer as layers:

What makes strange is within the below folder of AUX files, 4 could be opened in SNAP, I don’t know WHY? As they seem to have the SAME .DBL and HDR parts …

Sorry, as a new user, I can only paste one picture once …

The problem is why there are 4 could be read by SNAP but not the left ones? Their data format look exactly the same, and they are together provided as AUX data from ARRAY websites

Dear Yang Ya,

simply put: ESA did not commision us to implement support for these file types.

Sorry again,


Dear Tom,

… While … that’s too bad … I used to think that SNAP is the product designed by ESA for data processing …

That’s too bad …

May I ask you another question?

I downloaded and installed the SMOS MATLAB API under Linux, but because of don’t know how to setup directory and JAVA environment, I can not use it freely

Do you think it is possible to read these AUX .DBL data by IDL? Do you have such open source program to do this???

Dear Yang Na,

I have no experience with IDL for SMOS, I guess you just have to check it out.

Concerning MATLAB, I guess Luis (lveci) or at least his company built the MATLAB SMOS API, so he should know how to operate it - or at least know the people who programmed it.

Concerning the lack of AUX-data support for the file types you require: you can send a polite request for a SMOS.Box feature extension to ESA EOhelp (eohelp@esa.int) - this may trigger a software update process.

With best regards,


Dear Tom,

SO HAPPY to have your advice!!

I will try both!!! But, could you give more clues on Luis’ info, his full name and email address???

He is watching the forum - and I have sent him a short Skype-Note to contact you. Please understand: I will not post his personal details in a public forum.

Best regards,


yes… sorry for my misbehavior …

You can get the SMOS Matlab API from http://smos.array.ca
There is an email address from support in the contact us page.

Basically, you need up-to-date schemas to read the products with the API. However, we don’t distribute the schemas. You will need to contact eohelp at esa.int to ask for access to the schemas.