Help with modeling a sloped surface in gprMax

[farhad physic]

Dear gprMax Team,

Hi, I hope you're doing well.

I'm trying to build a simple model where the transmitter and receiver move along a sloped surface, similar to collecting GPR data over a hill with an upward slope. There is also a cavity beneath this surface. I have a .dat file with specific properties I’d like to use.

Is there any tutorial or example that shows how to model a slope like this? Or any similar model I could use as a reference?

I've attached an image from the dataset for clarification.

Best regards,
Farhad 

[Daniele Di Giorgio]

Maybe this can work:

Domain Setup

• Horizontal extent: 0 to 35 m

• Vertical extent: 0 to 20 m

• Discretization (dx dy dz): 0.01 m (1 cm) — suitable for 250 MHz

• Time window: 50 ns

---

Materials #material: 1 0.06 1.0 0.0 0.0 # Dry sand (εr ≈ 6) #material: 2 1.0 1.0 0.0 0.0 # Air (εr ≈ 1)

---

 Geometry

• Slope surface: modeled via #geometry_objects: (will approximate using #box or polygonal mesh).

• Cavity: rectangular #box assigned as air (Material 2)

---

🛰 Antenna Setup

• Waveform: Ricker wavelet, 250 MHz center frequency

• Scan type: B-scan with Tx/Rx pairs stepping downhill along the slope surface

---

• digitize the slope as a series of points and model it as a polygonal surface.

• The cavity will be a box (rectangular air-filled void).

create the actual slope_with_cavity.in GPRmax input file with:

• Material definitions

• Geometry (slope and cavity)

• Ricker waveform source (250 MHz)

• B-scan line going downhill

build the full input file.

Download the attchment.
This file includes:

• A sloped surface approximated with thin air boxes above sand

• A rectangular cavity of air

• A 250 MHz Ricker wavelet

• A B-scan line from the top to the bottom of the slope

You can run it using gprMax slope_with_cavity.in in your simulation environment.

Tell me if it worked!