Issues with DART simulation

[ym l]

Dear DART team,

My research requires using DART to simulate the temperatures and fractional abundances of different components in a 3D scene across various viewing directions. I have imported my 3D scene into the Punctual Objects module. The scene consists of two components: trees (with primary focus on their canopies) and bare soil. When creating the 3D scene model, I configured it with a flat terrain surface, and the corresponding ground elevation of the scene is approximately 800 meters.

However, I consistently encounter the warning shown in the attached figure when running the simulation. I have attempted to resolve this issue by modifying the 'Altitude of the DEM 'zero level'' parameter and the 'Elevation' parameter in the module that appears after importing the scene, but the problem persists.

Could you please advise me on how to avoid this warning? Additionally, I am unsure about how to adjust several parameters for this simulation and have therefore used their default values. I would greatly appreciate it if you could also indicate which parameters are particularly important for this type of simulation.

Thank you very much for your assistance!

Best regards,

Evelym

[Jean-Philippe Gastellu-Etchegorry]

Dear Evelyn, 

Thanks for your message. Can you send us a link to your simulation, please?

Best regards

DART Team

[ym l]

Dear DART Team,

Thank you very much for your prompt reply. I have packaged my current simulations and will send them to you immediately. Thank you again for your kind assistance.

Best regards

Evelym

https://drive.google.com/file/d/1Su6gVqANP6ajbZqpFiWJIfNa_2R9Adxv/view?usp=sharing

[Jean-Philippe Gastellu-Etchegorry]

Dear Evelym, 

I have started testing your simulation. I have a few remarks. 

Is there a good reason for creating directions with the option "Cosine weighted"?

The warnings are not important at all. In the new DART version (I will give you the link to this new version)., they do not appear. 

The aerosols and gas models are not consistent: USSTD76 or MidLatitude Summer?

You selected an optical property that is not adapted to your thermal infrared band. Then, DART extrapolates the higher value at the maximal wavelength up to your spectral band. 

I plan to prepare an "optimized" simulation that I will transmit to you. 

best regards

DART Team 

[ym l]

Dear DART Team,

Thank you so much for your incredibly detailed and constructive feedback, and for taking the time to test my simulation. Your guidance is invaluable to my work, and I truly appreciate your generosity in sharing your expertise.

To address your remarks one by one:

Regarding my use of the "Cosine weighted" option for directions: I selected this based on references suggesting it achieves higher integration accuracy with fewer directions, which I believed would be advantageous for my simulation. That said, I am fully open to any additional insights or recommendations you may have on this choice.

Thank you for clarifying that the warnings do not impact the simulation results, and for offering to share the link to the new DART version with me—this is very much appreciated.

For the aerosol and gas model settings, I intended to use the MidLatitude Summer , and I apologize for the oversight in keeping the settings consistent in my initial setup.

Your note about the optical properties not being adapted to my thermal infrared band was absolutely critical. I had not realized this mismatch at all, and your feedback has helped me avoid potentially significant biases in my subsequent research. I cannot thank you enough for pointing this out. I am also deeply grateful for your offer to prepare an "optimized" simulation setup for me. This will be an enormous help to my work, and I truly appreciate you going out of your way to support me in this way.

Thank you again for your patience, expertise, and generous support throughout this process.

Best regards,

Evelym