AeroVerifier: A Typed Spatial Verifier for Frozen Vision-Language Models in Aerial Visual Question Answering

Jinfeng Chen, Mengfan Yang, Jianyu Zhu, Zhicheng Zhou, Jing Liang


Abstract
Drone-based applications such as navigation, inspection, and search depend on vision-language models (VLMs) that can answer spatial visual questions. The VLM faces three challenging tasks: grounding each referenced phrase to a scene object, choosing a viewpoint for spatial relations, and verifying the relation against accurate 3D geometry. In current frozen VLMs, all three tasks happen inside a single forward pass, and only the final answer is visible from outside. As a result, when that answer is wrong, we cannot tell which task failed. To address this, we introduce AeroVerifier, which exposes each of these three tasks as an explicit and checkable interface. Given a question, AeroVerifier compiles it into an executable typed program, runs the program over object-level 3D evidence, and returns the program answer together with stage-wise diagnostic signals to the base VLM as single-step revision feedback. On a 1000-row Open3D-VQA subset, both AeroVerifier’s program answer and its revision feedback yield higher answer accuracy than the Qwen2.5-VL-7B and GPT-5.4 API baselines.
Anthology ID:
2026.findings-emnlp.1125
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
23826–23839
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1125/
DOI:
10.18653/2026.findings-emnlp.1125
Bibkey:
Cite (ACL):
Jinfeng Chen, Mengfan Yang, Jianyu Zhu, Zhicheng Zhou, and Jing Liang. 2026. AeroVerifier: A Typed Spatial Verifier for Frozen Vision-Language Models in Aerial Visual Question Answering. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 23826–23839, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
AeroVerifier: A Typed Spatial Verifier for Frozen Vision-Language Models in Aerial Visual Question Answering (Chen et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1125.pdf