Applying RCS Information to an Object in Winprop

Alvin Yang

Hi all,

I am trying to model reflections on square surface by using the Consider RCS Information in Altair's Proman.

I used CADFeko to open my square reflector model and requested FFE data with RCS data using the option "Calculate fields in plane wave incidence direction". I then did a simple model using Wallman to create a rectangular object to for the RCS data to be applied to (making the material out of metal). Finally in Proman, I applied the RCS data, with the RCS plot:

When I run the simulation with SRT, and Fresnel Coefficients, I can't seem to see or create any reflections. I have tried adjusting the Azimuth, as well as reorienting my model in CADFeko but I have had no luck.

Any help to figure out what I could be doing wrong with using the RCS data would be greatly appreciated.

If there is any other methods I can use to apply the reflections of a simulated model in Proman, other than the RCS, that would be a big help to.

 

Thanks!

reinerh

Hi Alvin,
thanks for your feedback!

The reflected ray from the RCS object is only given if the angular condition is met i.e. the reflected ray is going back into the direction where it is coming from. When defining in your project a single Rx point at the Tx location the reflected ray from the RCS object is computed and displayed, please find attached the corresponding point mode project.

Please note the RCS feature is made for the point mode analysis e.g. when for a radar sensor the Tx and Rx antennas are positioned at the same location. So in area mode the pixel close to the Tx is computed if the angular condition is met, so you need to define the lower left corner and resolution accordingly, attached the corresponding area mode project.

Best regards,

Reiner

Zeina

Hi Alvin,

Normally, adding RCS information of objects in ProMan is used when there are models with a lot of polygons to accelerate the run-time. Otherwise, you do not necessarily have to use that option to obtain reflections and other interactions while solving using the SRT method.

In order to check all your parameters and settings, is it possible for you to share your exported project (in ProMan: File-> Export-> Export Project as Zip Archive) along with the *.ffe file you are using for the RCS information?

Best Regards,

ZEina

Alvin Yang

Zeina said:

Hi Alvin,

Normally, adding RCS information of objects in ProMan is used when there are models with a lot of polygons to accelerate the run-time. Otherwise, you do not necessarily have to use that option to obtain reflections and other interactions while solving using the SRT method.

In order to check all your parameters and settings, is it possible for you to share your exported project (in ProMan: File-> Export-> Export Project as Zip Archive) along with the *.ffe file you are using for the RCS information?

Best Regards,

ZEina

Hi Zeina,

Thanks for the reply. I've attached the exported project. I have also tried looking into creating a directional antenna and using it as a repeater, but wasn't sure what source to use in CADFeko as I wanted to simulate the reflection when a signal hits the object.

reinerh

Hi Alvin,
thanks for sharing your project.
Please note that the RCS is mono-static so the reflected ray from the RCS object will be only given if the angular condition is met i.e. the reflected is going back into the direction where it is coming from (within a certain tolerance).

When defining in your project a single Rx point at the Tx location and disabling the Direct Ray (set to 'Never') the reflected ray from the RCS object is computed and displayed:

Best regards,

Reiner

Alvin Yang

reinerh said:

Hi Alvin,
thanks for sharing your project.
Please note that the RCS is mono-static so the reflected ray from the RCS object will be only given if the angular condition is met i.e. the reflected is going back into the direction where it is coming from (within a certain tolerance).

When defining in your project a single Rx point at the Tx location and disabling the Direct Ray (set to 'Never') the reflected ray from the RCS object is computed and displayed:

Best regards,

Reiner

Hi Reiner,

Thanks for the reply, setting the Direct Ray to never is very helpful when I'm trying to figure out if a ray is bouncing off my object. I created a project without any walls or furniture and tried running the propagation simulation twice, one with the RCS data applied, and one without.

Without RCS data:

 

With RCS data applied:

I feel pretty stumped, as I feel I should be seeing reflections off of the square after applying the RCS data. 

Alvin Yang

Alvin Yang said:

Hi Reiner,

Thanks for the reply, setting the Direct Ray to never is very helpful when I'm trying to figure out if a ray is bouncing off my object. I created a project without any walls or furniture and tried running the propagation simulation twice, one with the RCS data applied, and one without.

Without RCS data:

 

With RCS data applied:

I feel pretty stumped, as I feel I should be seeing reflections off of the square after applying the RCS data. 

I almost forgot, I attached the cleaned up version of the project if it helps.

 

reinerh

Hi Alvin,
thanks for your feedback!

The reflected ray from the RCS object is only given if the angular condition is met i.e. the reflected ray is going back into the direction where it is coming from. When defining in your project a single Rx point at the Tx location the reflected ray from the RCS object is computed and displayed, please find attached the corresponding point mode project.

Please note the RCS feature is made for the point mode analysis e.g. when for a radar sensor the Tx and Rx antennas are positioned at the same location. So in area mode the pixel close to the Tx is computed if the angular condition is met, so you need to define the lower left corner and resolution accordingly, attached the corresponding area mode project.

Best regards,

Reiner

Alvin Yang

reinerh said:

Hi Alvin,
thanks for your feedback!

The reflected ray from the RCS object is only given if the angular condition is met i.e. the reflected ray is going back into the direction where it is coming from. When defining in your project a single Rx point at the Tx location the reflected ray from the RCS object is computed and displayed, please find attached the corresponding point mode project.

Please note the RCS feature is made for the point mode analysis e.g. when for a radar sensor the Tx and Rx antennas are positioned at the same location. So in area mode the pixel close to the Tx is computed if the angular condition is met, so you need to define the lower left corner and resolution accordingly, attached the corresponding area mode project.

Best regards,

Reiner

Hi Reiner,

Thanks for the attached projects. I took a look through them, and I understand the RCS better. It is confusing to me that making the resolution finer, seems to make the paths not appear. I've tried increasing the resolution you had from 0.1m -> 1m

The reflected path looks like its pathing to the center of the square. Thanks so much for the help with understanding the RCS. My end goal is to run a network simulation with the reflector, so I wanted to ask if you knew if it was possible to run this simulation at the finer resolution, while being able to keep the reflector?  

reinerh

Hi Alvin,
thanks for your further inputs.
In the current WinProp version the RCS backscattering is only considered for a single pixel as this RCS feature is made for the point mode analysis. Therefore it can be hardly used for the area mode.
We will enhance this for the 2023.1 release, so that more than one pixel will get a ray from the RCS object. But even then still the angular condition for monostatic RCS needs to be met, so only the pixels which are in the right direction from the RCS object will be computed.

Alternatively you might try to emulate the RCS object by placing another transmitter (i.e. repeater of the given Tx antenna) in your network project at the location of the RCS object and then assign to the repeater the corresponding antenna pattern as computed in Feko (for the given angle of incidence).

Best regards,

Reiner

Alvin Yang

reinerh said:

Hi Alvin,
thanks for your further inputs.
In the current WinProp version the RCS backscattering is only considered for a single pixel as this RCS feature is made for the point mode analysis. Therefore it can be hardly used for the area mode.
We will enhance this for the 2023.1 release, so that more than one pixel will get a ray from the RCS object. But even then still the angular condition for monostatic RCS needs to be met, so only the pixels which are in the right direction from the RCS object will be computed.

Alternatively you might try to emulate the RCS object by placing another transmitter (i.e. repeater of the given Tx antenna) in your network project at the location of the RCS object and then assign to the repeater the corresponding antenna pattern as computed in Feko (for the given angle of incidence).

Best regards,

Reiner

Hi Reiner,

Thanks for the suggestion, I think this closes my exploration with using RCS. I appreciate all the help. I've attempted setting an antenna as a repeater mode, but have run into issues getting it to work. I plan to create a new question for this problem. 

 

Thanks again!

Alvin