Organizations: School of Remote Sensing and Information Engineering, Wuhan University, Wuhan, 430079, China · First Surveying and Mapping Institute of Hunan Province, Changsha, 421001, China
Cross-modal Geo-localization (CMGL) matches ground-level text descriptions with geo-tagged aerial imagery, which is crucial for pedestrian navigation and emergency response. However, existing studies are constrained by narrow geographic coverage and simplistic scene diversity, failing to reflect the immense spatial heterogeneity of global architectural styles and topographic features. To bridge this gap and facilitate universal positioning, we introduce CORE, the first million-scale dataset dedicated to global CMGL. CORE comprises 1,034,786 cross-view images sampled from 225 distinct geographic regions across six continents, offering an unprecedented variety of perspectives in varying environmental conditions and urban layouts. We leverage the zero-shot reasoning of Large Vision-Language Models (LVLMs) to synthesize high-quality scene descriptions rich in discriminative cues. Furthermore, we propose a physical-law-aware network (PLANET) for cross-modal geo-localization. PLANET introduces a novel contrastive learning paradigm to guide textual representations in capturing the intrinsic physical signatures of satellite imagery. Extensive experiments across varied geographic regions demonstrate that PLANET significantly outperforms state-of-the-art methods, establishing a new benchmark for robust, global-scale geo-localization. The dataset and source code will be released at https://github.com/YtH0823/CORE.
Figures & tables
Figure 1: Illustration of cross-modal geo-localization. This task retrieves satellite imagery based on text queries of the ground environment for position localization. The physical attribute information presented in the text description can yield valuable clues regarding the location.
Dataset
Image Type
Query Image
Reference Image
Total Image
Text Annotation
Distribution
Environment
CVGL
CVUSA ( Workman et al., 2015 )
Street-view
44,416
44,416
88,832
×
USA
Suburban
CVACT ( Liu and Li, 2019 )
Street-view
128,334
128,334
256,668
×
Canberra
Urban
VIGOR ( Zhu et al., 2021 )
Street-view
90,618
105,214
195,832
×
USA
Urban
University-1652 ( Zheng et al., 2020 )
Drone and Street-view
50,218
55,227
105,445
×
Campus
Urban
CVGlobal ( Ye et al., 2024 )
Street-view
134,233
134,233
268,466
×
Global (7 regions)
Urban
Table 1: Comparison of the CORE dataset with other geo-localization datasets. The comparison includes the number of reference and query images, text annotations, distribution range, and sampling environment.
Figure 2: We evaluate representative methods on the CORE dataset and the existing CVG-Text dataset, with PLANET achieving state-of-the-art performance in 8 settings, demonstrating strong localization capabilities. All results are reported as R@1, and the radial axis is linearly scaled from 20 to 70.
Figure 3: Geographical distribution map of sampled images and corresponding text annotations from the CORE dataset. CORE exhibits unprecedented global scale and spatial heterogeneity. This extensive diversity ensures a comprehensive representation of varying urban and suburban environments worldwide.
Figure 4: Annotation pipeline of the CORE dataset. Manual templates guide Qwen3-VL-Plus generation, and every generated description is manually reviewed and corrected.
Figure 5: Word cloud analysis of text descriptions from the CORE dataset.
Figure 6: Overview of text feature statistics in the CORE dataset. (a) Token length distribution histogram; (b) Text statistics comparison between the CORE dataset and existing CMGL datasets; (c) Text similarity matrix.
Figure 7: Pipeline of the proposed PLANET. (a) During training, image statistics are computed directly from the input satellite images and aligned with the projected text descriptors. (b) During inference, global query and gallery features are matched by similarity without the auxiliary statistical branches.
Method
Global-level
Intercontinental-level
All
Subset1
Subset2
Subset3
Subset4
R@1
L@150
R@1
L@150
R@1
L@150
R@1
L@150
R@1
L@150
ViLT ( Kim et al., 2021 )
23.05
26.23
24.43
26.18
22.08
25.34
25.58
30.79
19.65
25.07
X-VLM ( Zeng et al., 2022 )
26.97
30.81
28.90
30.65
25.72
28.74
28.67
33.86
24.31
29.62
X2-VLM ( Zeng et al., 2023 )
34.35
38.33
35.79
38.50
33.73
36.56
36.12
41.25
31.43
36.61
SigLIP-B/16 ( Zhai et al., 2023 )
30.10
34.08
29.13
31.87
30.87
33.92
31.23
36.18
28.98
34.20
Table 2: Quantitative results of PLANET and existing methods on the CORE dataset. We report the retrieval recall ( R@1 ) and localization accuracy ( L@150 ) across the World-level and four intercontinental subsets. All methods are fine-tuned on the CORE training split under a unified training protocol. Bold indicates the best result, and underline indicates the second best result.
Figure 8: The retrieval results of PLANET on the CORE dataset. The left side displays the original street view image along with its corresponding textual description. The right side illustrates the top four retrieval results, where green highlights indicate correct matches and red highlights signify incorrect results.
Figure 9: Failure cases of PLANET on the CORE dataset. For each query, the right side shows the top four retrieval results in row-major order from Rank-1 to Rank-4. Green boxes denote the ground-truth satellite images, while red boxes denote incorrect retrieved candidates.
Figure 10: Top-3 retrieval results and satellite heatmaps for PLANET and the baseline, together with PLANET’s token-level attention visualization of the query text. Green and red boxes denote correct and incorrect retrievals, respectively, and tokens with stronger PLANET attention responses correspond to discriminative physical attributes in the scene. The introduction of physical consistency constraints enables PLANET to more accurately anchor its attention on crucial geographical regions.
Figure 11: UMAP visualization of the feature distribution of the CORE dataset. Compared to the baseline (left), PLANET (right) significantly enhances the discriminative power of features by introducing physical property constraints. Samples from different subsets (distinguished by color) exhibit higher intra-class cohesion and clearer inter-class boundaries in space, while achieving tighter cross-modal alignment between images (circles) and text (stars).
Method
Subset 1
Subset 2
Subset 3
Subset 4
R@1
L@150
R@1
L@150
R@1
L@150
R@1
L@150
Baseline (w/o Physical)
53.12
55.88
59.36
62.37
46.97
51.27
48.71
54.61
+ Color ( fcolor )
55.81
58.23
62.58
65.10
47.93
52.20
49.83
55.07
+ Structure ( fstruc )
55.78
58.16
62.32
64.98
48.03
52.24
49.52
55.12
+ Texture ( ftex )
55.43
58.10
62.46
65.08
48.21
52.53
49.95
55.48
+ Color + Structure ( fcolor+fstruc )
56.64
59.43
63.98
66.77
48.86
53.21
50.50
56.03
Table 3: Ablation study on the physical consistency mechanism. We investigate the impact of explicit physical constraints by comparing our PLANET variants against the baseline.
Variant
Weights
∑
R@1 (%) on CORE Subsets
λc
λs
λt
Sub 1
Sub 2
Sub 3
Sub 4
(a) Ablation on Overall Weight (Fixed 1:1:1 Ratio)
Under-regularized
0.1
0.1
0.1
0.3
54.12 ± 0.07
60.83 ± 0.08
47.58 ± 0.12
49.97 ± 0.04
Under-regularized
0.2
0.2
0.2
0.6
56.43 ± 0.06
63.15 ± 0.13
48.76 ± 0.08
50.66 ± 0.07
Over-regularized
0.5
0.5
0.5
1.5
57.07 ± 0.13
63.88 ± 0.11
49.26 ± 0.10
50.92 ± 0.12
Over-regularized
1.0
1.0
1.0
3.0
54.82 ± 0.15
60.75 ± 0.17
48.04 ± 0.15
50.23 ± 0.14
Table 4: Ablation study on the weighting coefficients of the physical consistency constraints across four subsets of the CORE dataset. We report the R@1 (%) metric.
Bins
Subset 1
Subset 2
Subset 3
Subset 4
R@1
L@150
R@1
L@150
R@1
L@150
R@1
L@150
8
57.08
59.76
63.88
66.57
48.95
53.37
50.39
55.88
16
57.43
60.27
64.32
67.13
49.28
53.64
50.95
56.13
32
57.90
60.72
64.74
67.58
49.81
54.13
51.35
56.65
64
57.52
60.33
64.38
67.09
49.21
53.58
51.02
56.27
128
57.17
59.91
64.03
66.75
48.88
53.26
50.62
55.95
Table 5: Ablation study on the histogram bin number of physical descriptors. We report R@1 (%) and L@150 (%) across four subsets of the CORE dataset.
Method
Backbone
Params (M)
FLOPs (G)
Memory (GB)
Retrieval Time (ms)
R@1
L@150
Baseline
CLIP-ViT-L/14@336px
428.12
401.03
30.45
49.97
53.12
55.88
PLANET
CLIP-ViT-B/32
155.06
32.58
6.43
31.28
41.03
44.22
CLIP-ViT-B/16
153.40
57.57
8.40
31.93
44.49
47.22
CLIP-ViT-L/14@336px
431.79
403.16
30.46
50.08
57.90
60.72
Table 6: Efficiency and accuracy comparison on CORE Subset 1. The baseline uses the original CLIP-ViT-L/14@336px backbone, while PLANET is evaluated with different CLIP backbones. Retrieval time denotes the average retrieval time for a single query.
Setting
R@1
L@150
R@1 Drop
L@150 Drop
Full text
57.90
60.72
–
–
Entity only
10.93
12.52
46.97
48.20
w/o Entity
36.20
38.86
21.70
21.86
w/o Attribute
34.66
36.98
23.24
23.74
w/o Color
49.30
52.05
8.60
8.67
w/o Structure
45.24
47.74
12.66
12.98
Table 7: Text cue ablation study on CORE Subset 1. We remove one cue group from the query during testing, while the Entity only setting retains only entity words. The trained model and retrieval gallery remain unchanged.
Method
Subset1 → 4
Subset2 → 4
Subset3 → 4
R@1
L@150
R@1
L@150
R@1
L@150
TAG-CLIP
12.22
14.13
11.83
13.79
14.79
17.06
BLIP
15.24
17.93
14.17
16.58
16.84
19.35
CLIP-L/14
15.58
18.25
14.34
16.62
17.22
19.83
Long-CLIP
21.68
25.07
19.75
22.86
22.96
26.10
CrossText2Loc
23.13
26.97
21.06
24.64
24.75
28.12
Table 8: Quantitative comparison of out-of-distribution generalization on CORE dataset.
Method
New York
Brisbane
Tokyo
R@1
L@50
R@1
L@50
R@1
L@50
ViLT ( Kim et al., 2021 )
11.58
15.58
11.10
14.50
10.83
15.50
X-VLM ( Zeng et al., 2022 )
15.74
16.86
15.67
17.60
12.46
14.34
X2-VLM ( Zeng et al., 2023 )
23.33
25.17
21.58
23.67
17.83
20.75
SigLIP-B/16 ( Zhai et al., 2023 )
19.67
21.08
19.58
22.00
15.58
17.92
SigLIP-SO400M ( Zhai et al., 2023 )
33.50
34.83
34.25
36.83
28.42
31.50
Table 9: Quantitative comparison of different methods on the CVG-Text dataset.
Training Set
Test Set
R@1
L@50
L@150
CORE
CVG-Text New York
23.17
25.25
29.42
CVG-Text Brisbane
26.33
29.83
30.50
CVG-Text Tokyo
19.92
22.75
23.58
CVG-Text
CORE Subset1
8.03
8.85
10.36
CORE Subset2
9.14
9.98
12.57
CORE Subset3
7.75
8.52
9.85
Table 10: Cross-dataset generalization of PLANET between CORE and CVG-Text. The model is trained on the source dataset and directly evaluated on the target dataset without additional fine-tuning.
College of Computer Science and Technology and Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education, Jilin University, Changchun 130012, China · Zhongguancun Academy, Beijing 100094, China · School of Computer Science, Wuhan University, Wuhan, China +1