# Ozone Cues Mitigate Reflected Downwelling Radiance in LWIR Absorption-Based Ranging

arXiv: https://arxiv.org/abs/2603.00273 · HTML: https://mlsanity.com/paper/2603.00273/

## Key facts

- Cited by 3 papers in the map (data through 14 Oct 2026).
- Builds on 5 of its 55 references that are in the map.
- First posted on arXiv 27 Feb 2026.

## Builds on (most cited first, 5 of 5)

- [Non-line-of-sight Imaging](https://mlsanity.com/paper/2005.08026/) (2020)
- [Why are thermal images blurry](https://mlsanity.com/paper/2307.15800/) (2023)
- [Absorption-Based, Passive Range Imaging from Hyperspectral Thermal Measurements](https://mlsanity.com/paper/2308.05818/) (2023)
- [Mapping with Reflection -- Detection and Utilization of Reflection in 3D Lidar Scans](https://mlsanity.com/paper/1909.12483/) (2019)
- [Photometric Stereo in Participating Media Considering Shape-Dependent Forward Scatter](https://mlsanity.com/paper/1804.02836/) (2018)

## Built on by (most cited first, 3 of 3)

- [Absorption-Feature-Guided Distance-Decoupled Estimation and Band Selection for LWIR Hyperspectral Passive Ranging](https://mlsanity.com/paper/2606.31824/) (2026)
- [T2exture: Sparsely Perturbed Thermal-to-Texture Imaging](https://mlsanity.com/paper/2608.02192/) (2026)
- [Passive LWIR Hyperspectral Ranging via Transmittance Extraction and Distance Alignment](https://mlsanity.com/paper/2609.28967/) (2026)

## Abstract (arXiv)

Passive long-wave infrared (LWIR) absorption-based ranging relies on atmospheric absorption to estimate distances to objects from their emitted thermal radiation. First demonstrated decades ago for objects much hotter than the air and recently extended to scenes with low temperature variations, this ranging has depended on reflected radiance being negligible. Downwelling radiance is especially problematic, sometimes causing large inaccuracies. In two new ranging methods, we use characteristic features from ozone absorption to estimate the contribution of reflected downwelling radiance. The quadspectral method gives a simple closed-form range estimate from four narrowband measurements, two at a water vapor absorption line and two at an ozone absorption line. The hyperspectral method uses a broader spectral range to improve accuracy while also providing estimates of temperature, emissivity profiles, and contributions of downwelling from a collection of zenith angles. Experimental results demonstrate improved ranging accuracy, in one case reducing error from over 100 m when reflected light is not modeled to 6.8 m with the quadspectral method and 1.2 m with the hyperspectral method.