Evaluating Multimodal Large Language Models for Geospatial Object Identification and Enumeration in Overhead Imagery
摘要
This work explores the use of multimodal large language models (MLLMs) for geospatial object detection and enumeration in satellite imagery. Using the publicly available RarePlanes [1] dataset with pre-chipped satellite imagery, we evaluate nine frontier MLLMs on their ability to detect and classify aircraft in overhead imagery. Each model is provided with ontology class definitions and structured output requirements to identify and count aircraft across seven categories. We assess model performance on 300 representative image samples, measuring both object enumeration and classification accuracy. Our methodology examines model sensitivity to object scale, density, and visual context, and probes the extent to which MLLMs can support dynamic, zero-shot search without external embeddings or traditional computer vision models. By isolating the MLLM as a reasoning engine over visual data, this study informs the design of agentic pipelines for automated broad-area search, where adaptability, task generalization, and structured spatial reasoning are essential for defense and intelligence applications.