Information
- Publication Type: Bachelor Thesis
- Workgroup(s)/Project(s):
- Date: June 2026
- Date (Start): 1. January 2026
- Date (End): 25. June 2026
- Matrikelnummer: 12122563
- First Supervisor: Eduard Gröller
Abstract
This thesis presents an interactive visualization approach for integrating subsurface radar data acquired by the Radar Imager for Mars’ Subsurface Experiment (RIMFAX) into a three-dimensional terrain context. RIMFAX radargrams represent subsurface reflections recorded along the Perseverance rover traverse and are therefore two-dimensional data embedded in three-dimensional space. To improve their spatial interpretability, this work investigates cross-sections that open the terrain along a selected path and display the corresponding radargram on a curtain-shaped surface.The developed prototype supports both interactively drawn paths and imported rover traverses. A central challenge is the consistent classification of the terrain for paths containing sharp turns, concave regions, loops, or selfintersections. Several local approaches were investigated, including tiled clipping planes and a nearest-point heuristic based on a frozen viewing direction. These methods produced inconsistent or visually unclear classifications for geometrically complex paths.
The final method reformulates the clipping problem as a two-dimensional point-in-polygon classification. The path is combined with an additional reference point to form a closed polygon, and terrain vertices are projected into a common two-dimensional coordinate system and classified as inside or outside this polygon. The classification is computed on the CPU and transferred to the GPU as a per-vertex attribute, where interpolation and fragment discarding produce the visible terrain cut. For fixed inputs, this approach provides stable and reproducible results and handles concave paths more consistently than the explored local methods.
A continuous curtain is generated along the complete cross-section path by expanding its line segments into vertical quads. Normalized arc-length texture coordinates provide a continuous horizontal parameterization and allow the radargram to be mapped according to distance along the path.
The implementation is written in F# using the Aardvark Platform and processes the terrain through its Out-of-Core Point Cloud (OPC) patch hierarchy. It therefore uses technologies, data structures, and rendering mechanisms compatible with later integration into PRo3D. Performance was evaluated on a system equipped with an 11th Gen Intel Core i7-1165G7 processor, Intel Iris Xe Graphics, and 16 GB of RAM. For the evaluated terrain view, the classification of approximately 1.91 million vertices required approximately 1.21 seconds on average. After classification, navigation with clipping and curtain rendering enabled remained interactive at approximately 54 frames per second during continuous camera movement.
The results demonstrate that the method provides a practical foundation for embedding RIMFAX radargrams into their corresponding terrain context. Remaining limitations include spikes along the clipped terrain boundary, gaps or overlaps between the terrain and curtain, preprocessing requirements for the radargram imagery, and semantically ambiguous results for some self-intersecting paths.
Additional Files and Images
Weblinks
No further information available.BibTeX
@bachelorsthesis{kloos-2026-icv,
title = "Interactive Cross-Section Visualization of RIMFAX Subsurface
Data for PRo3D",
author = "Lucia Kloos",
year = "2026",
abstract = "This thesis presents an interactive visualization approach
for integrating subsurface radar data acquired by the Radar
Imager for Mars’ Subsurface Experiment (RIMFAX) into a
three-dimensional terrain context. RIMFAX radargrams
represent subsurface reflections recorded along the
Perseverance rover traverse and are therefore
two-dimensional data embedded in three-dimensional space. To
improve their spatial interpretability, this work
investigates cross-sections that open the terrain along a
selected path and display the corresponding radargram on a
curtain-shaped surface. The developed prototype supports
both interactively drawn paths and imported rover traverses.
A central challenge is the consistent classification of the
terrain for paths containing sharp turns, concave regions,
loops, or selfintersections. Several local approaches were
investigated, including tiled clipping planes and a
nearest-point heuristic based on a frozen viewing direction.
These methods produced inconsistent or visually unclear
classifications for geometrically complex paths. The final
method reformulates the clipping problem as a
two-dimensional point-in-polygon classification. The path is
combined with an additional reference point to form a closed
polygon, and terrain vertices are projected into a common
two-dimensional coordinate system and classified as inside
or outside this polygon. The classification is computed on
the CPU and transferred to the GPU as a per-vertex
attribute, where interpolation and fragment discarding
produce the visible terrain cut. For fixed inputs, this
approach provides stable and reproducible results and
handles concave paths more consistently than the explored
local methods. A continuous curtain is generated along the
complete cross-section path by expanding its line segments
into vertical quads. Normalized arc-length texture
coordinates provide a continuous horizontal parameterization
and allow the radargram to be mapped according to distance
along the path. The implementation is written in F# using
the Aardvark Platform and processes the terrain through its
Out-of-Core Point Cloud (OPC) patch hierarchy. It therefore
uses technologies, data structures, and rendering mechanisms
compatible with later integration into PRo3D. Performance
was evaluated on a system equipped with an 11th Gen Intel
Core i7-1165G7 processor, Intel Iris Xe Graphics, and 16 GB
of RAM. For the evaluated terrain view, the classification
of approximately 1.91 million vertices required
approximately 1.21 seconds on average. After classification,
navigation with clipping and curtain rendering enabled
remained interactive at approximately 54 frames per second
during continuous camera movement. The results demonstrate
that the method provides a practical foundation for
embedding RIMFAX radargrams into their corresponding terrain
context. Remaining limitations include spikes along the
clipped terrain boundary, gaps or overlaps between the
terrain and curtain, preprocessing requirements for the
radargram imagery, and semantically ambiguous results for
some self-intersecting paths.",
month = jun,
address = "Favoritenstrasse 9-11/E193-02, A-1040 Vienna, Austria",
school = "Research Unit of Computer Graphics, Institute of Visual
Computing and Human-Centered Technology, Faculty of
Informatics, TU Wien ",
URL = "https://www.cg.tuwien.ac.at/research/publications/2026/kloos-2026-icv/",
}