How to run PML algorithm in command line?

Please enter here to ask a question about any NASA Science related topics!
Post Reply
ryuya1001
Posts: 4
Joined: Fri Sep 17, 2021 2:27 am America/New_York

How to run PML algorithm in command line?

by ryuya1001 » Tue Oct 05, 2021 1:23 am America/New_York

Hello.
I would like to use the l2gen command to run the PML algorithm.
As far as I have checked, SEAWIFS and MODIS seem to provide a lookup table for the PML algorithm.
However, there is no parameter file for the PML algorithm.
How can I get the PML algorithm to work properly?
Thank you very much for your help.

Tags:

OB.DAAC - SeanBailey
User Services
User Services
Posts: 1220
Joined: Wed Sep 18, 2019 6:15 pm America/New_York
Answers: 1

Re: How to run PML algorithm in command line?

by OB.DAAC - SeanBailey » Tue Oct 05, 2021 4:00 pm America/New_York

The available products for the PML algorithm are:
bbp_###_pml
aph_###_pml
adg_###_pml
a_###_pml
bb_###_pml

(### is a short hand for all the wavelength, so a_443_pml will give you total absorption at 443nm)

Regards,
Sean

ryuya1001
Posts: 4
Joined: Fri Sep 17, 2021 2:27 am America/New_York

Re: How to run PML algorithm in command line?

by ryuya1001 » Thu Oct 07, 2021 1:37 am America/New_York

Thank you for your reply.
When I run l2gen with PML parameters, I got segmentation fault in the middle of the run(Other algorithms such as QAA are working fine). Is this a problem with my research environment? I am currently running Linux on a virtual box.

best regards,

Here is the output.
--------
Loading default parameters for SeaWiFS from /home/matsushita/OCSSW/ocssw/share/seawifs/msl12_defaults.par
Loading parameters for suite PML from /home/matsushita/OCSSW/ocssw/share/seawifs/msl12_defaults_PML.par
Loading command line parameters
...
The following products will be included in test_pml.nc.
0 adg_412_pml
1 adg_443_pml
...
Processing scan # 0 (1 of 479) after 0 seconds
chl_hu: using 443.00 555.00 670.00
Loading PML IOP model config file: /home/matsushita/OCSSW/ocssw/share/common/pml.cfg
Segmentation fault (Core damped)
---------

OB.DAAC - SeanBailey
User Services
User Services
Posts: 1220
Joined: Wed Sep 18, 2019 6:15 pm America/New_York
Answers: 1

Re: How to run PML algorithm in command line?

by OB.DAAC - SeanBailey » Fri Oct 08, 2021 9:07 am America/New_York

Works for me. Can you provide specifics on the inputs you used (input file and parameters)?

Sean

ryuya1001
Posts: 4
Joined: Fri Sep 17, 2021 2:27 am America/New_York

Re: How to run PML algorithm in command line?

by ryuya1001 » Fri Oct 15, 2021 12:32 am America/New_York

This is the input file and parameter file I used.

--Input file--

/begin_header
/sensor=SEAWIFS
/delimiter=comma
/missing=-9999
/fields=lat,lon,Rrs_412,Rrs_443,Rrs_490,Rrs_510,Rrs_555,Rrs_670
/units=degrees,degrees,1/sr,1/sr,1/sr,1/sr,1/sr,1/sr
/end_header
27.5427,-82.7977,0.00973016,0.0131515,0.0195598,0.0207276,0.0223573,0.00534573
27.4627,-82.9656,0.00698901,0.00834473,0.0112343,0.00976069,0.00699265,0.000692738
27.3877,-83.1341,0.00490524,0.00527858,0.00583139,0.00416109,0.00227736,0.000198105
27.3116,-83.3003,0.00651514,0.00648285,0.00682826,0.00496975,0.00277854,0.000197754
26.7689,-83.724,0.00518317,0.00464409,0.00448592,0.00322491,0.00165828,9.79e-05
26.8497,-83.5604,0.00600995,0.00558749,0.00535687,0.00367817,0.00188847,9.91e-05

--parameter file--
l2prod=adg_vvv_pml,aph_vvv_pml,a_vvv_pml,bbp_vvv_pml

Best regards,

OB.DAAC - SeanBailey
User Services
User Services
Posts: 1220
Joined: Wed Sep 18, 2019 6:15 pm America/New_York
Answers: 1

Re: How to run PML algorithm in command line?

by OB.DAAC - SeanBailey » Fri Oct 15, 2021 9:12 am America/New_York

Ah, well, you're passing in SeaBASS file, not a SeaWiFS file. The PML algorithm requires the view geometry. The l2gen SeaBASS file reader does not populate the geometries. The PML code does not check to see that valid values are passed and when it tries to interpolate the LUT with negative indices (the geometries are fill values which are -32767) it blows up (segfaults).

In a future release, we may modify the SeaBASS reader to allow it to read the view geometries, but for now, the answer is l2gen can't do what you want it to do.

Sorry,
Sean

ryuya1001
Posts: 4
Joined: Fri Sep 17, 2021 2:27 am America/New_York

Re: How to run PML algorithm in command line?

by ryuya1001 » Sun Oct 17, 2021 8:10 pm America/New_York

Thank you for your detailed explanation.
I understand that it is currently not possible to run PML using l2gen.
Thank you very much for your kind communication.

Best regards,

OB.DAAC - SeanBailey
User Services
User Services
Posts: 1220
Joined: Wed Sep 18, 2019 6:15 pm America/New_York
Answers: 1

Re: How to run PML algorithm in command line?

by OB.DAAC - SeanBailey » Mon Oct 18, 2021 9:43 am America/New_York

To be clear, the PML algorithm in l2gen works when the source data is a satellite L1 file. It only has an issue when the source is a SeaBASS-formatted ASCII text file. :D

Post Reply