---
title: Core-S2L2A-249k
canonical_url: "https://www.modelscope.cn/datasets/Major-TOM/Core-S2L2A-249k"
md_url: "https://www.modelscope.cn/datasets/Major-TOM/Core-S2L2A-249k.md"
repository: Major-TOM/Core-S2L2A-249k
last_updated: 2026-05-21
license: cc-by-sa-4.0
storage_size: "328 GB"
downloads: 14109
stars: 1
---

# Core-S2L2A-249k

> Core-S2L2A-249k - Major-TOM 在 ModelScope 开源的数据集。Core-S2L2A-249k is a curated subset of the Major-TOM Core-S2L2A dataset, containing 248,719 Sentinel-2 L2A image patches uniformly sampled across the globe. It serves as the source imagery for pre-computed…

Major-TOM/Core-S2L2A-249k 是 ModelScope 魔搭社区上的数据集，存储大小 328 GB，采用 cc-by-sa-4.0 许可。

- **Repository**: Major-TOM/Core-S2L2A-249k
- **License**: cc-by-sa-4.0
- **Storage size**: 328 GB
- **Downloads**: 14109
- **Stars**: 1
- **Last updated**: 2026-05-21

Source: https://www.modelscope.cn/datasets/Major-TOM/Core-S2L2A-249k

---

# Core-S2L2A-249k

**Core-S2L2A-249k** is a curated subset of the [Major-TOM](https://github.com/ESA-PhiLab/MajorTOM) Core-S2L2A dataset, containing 248,719 Sentinel-2 L2A image patches uniformly sampled across the globe. It serves as the **source imagery** for pre-computed embedding datasets used by the [EarthEmbeddingExplorer](https://modelscope.ai/studios/Major-TOM/EarthEmbeddingExplorer) cross-modal retrieval web application.

## Overview

| Property | Value |
|----------|-------|
| Source | Major-TOM Core-S2L2A |
| Sensor | Sentinel-2 MSI (Level-2A) |
| Number of patches | 248,719 |
| Patch size | 384 × 384 pixels |
| Spectral bands | 12 (B01, B02, B03, B04, B05, B06, B07, B08, B8A, B09, B11, B12) |
| Spatial resolution | 10 m / 20 m / 60 m (depending on band) |
| Output format | GeoParquet |
| License | CC-BY-SA-4.0 |

## Sampling Strategy

This dataset was created by **uniform grid sampling** from the full Major-TOM Core-S2L2A archive:

1. A global grid is overlaid on the Major-TOM tile index.
2. For every **1/9 sampled grid cell**, the central bounding box is selected as the crop region.
3. Each crop is extracted at a fixed size of **384 × 384 pixels** to ensure consistency across all downstream embedding models.

This strategy guarantees spatial diversity while keeping the dataset size manageable for large-scale embedding generation and interactive web retrieval.

## File Layout

```
.
├── metadata_249k.parquet          # Metadata and geospatial index (248,719 rows)
└── images_249k/
    ├── part_00001.parquet         # Image patches shard 1
    ├── part_00002.parquet         # Image patches shard 2
    └── ...
```

### Metadata Schema (`metadata_249k.parquet`)

| Column | Type | Description |
|--------|------|-------------|
| `product_id` | string | Original Sentinel-2 product identifier |
| `timestamp` | datetime | Acquisition timestamp |
| `grid_cell` | string | Major-TOM grid cell identifier |
| `grid_row_u` | int16 | Grid row index |
| `grid_col_r` | int16 | Grid column index |
| `geometry` | geometry | WGS-84 polygon (footprint) |
| `centre_lat` | float32 | Latitude of patch centre |
| `centre_lon` | float32 | Longitude of patch centre |
| `utm_footprint` | string | Original UTM footprint as WKT |
| `utm_crs` | string | UTM CRS (e.g. EPSG:32633) |
| `pixel_bbox` | list<int> | Pixel bounding box [x_min, y_min, x_max, y_max] |
| `parquet_url` | string | Path to the image shard containing this patch |
| `parquet_row` | int64 | Row index within the image shard |

### Image Patch Schema (`images_249k/part_*.parquet`)

Each row contains a single 384 × 384 Sentinel-2 L2A patch stored as a 3-D array with shape `(384, 384, 12)` in uint16 format. The 12 bands follow the order:

`[B01, B02, B03, B04, B05, B06, B07, B08, B8A, B09, B11, B12]`

## Pre-computed Embedding Datasets

The following embedding datasets were computed from **Core-S2L2A-249k** using various foundation models. All embeddings share the same 248,719 samples and geospatial metadata, enabling fair cross-model comparison.

| Filename | Embedding Model | Crop Size | Model Input Size | Embedding Dim | Source |
|----------|-----------------|-----------|------------------|---------------|--------|
| `SigLIP_crop_384x384.parquet` | [SigLIP (ViT-SO400M-14-SigLIP-384)](https://huggingface.co/timm/ViT-SO400M-14-SigLIP-384) | 384×384 | 384×384 | 1152 | [Major-TOM/Core-S2RGB-249k-SigLIP](https://modelscope.cn/datasets/Major-TOM/Core-S2RGB-249k-SigLIP) |
| `FarSLIP_crop_384x384.parquet` | [FarSLIP (ViT-B-16)](https://huggingface.co/ZhenShiL/FarSLIP) | 384×384 | 224×224 | 512 | [Major-TOM/Core-S2RGB-249k-FarSLIP](https://modelscope.cn/datasets/Major-TOM/Core-S2RGB-249k-FarSLIP) |
| `DINOv2_crop_384x384.parquet` | [DINOv2-large](https://huggingface.co/facebook/dinov2-large) | 384×384 | 224×224 | 1024 | [Major-TOM/Core-S2RGB-249k-DINOv2](https://modelscope.cn/datasets/Major-TOM/Core-S2RGB-249k-DINOv2) |
| `SatCLIP_crop_384x384.parquet` | [SatCLIP (ViT16-L40)](https://github.com/microsoft/satclip) | 384×384 | 224×224 | 256 | [Major-TOM/Core-S2L2A-249k-SatCLIP](https://modelscope.cn/datasets/Major-TOM/Core-S2L2A-249k-SatCLIP) |
| `Clay_crop_384x384.parquet` | [Clay v1.5](https://github.com/Clay-foundation/model) | 384×384 | 384×384 | 1024 | [Major-TOM/Core-S2L2A-249k-Clay-v1_5](https://modelscope.cn/datasets/Major-TOM/Core-S2L2A-249k-Clay-v1_5) |
| `OLMoEarth_Base_crop_384x384.parquet` | [OLMoEarth-Base](https://huggingface.co/allenai/OLMoEarth-Base-WS) | 384×384 | 128×128 | 768 | [Major-TOM/Core-S2L2A-249k-OlmoEarth](https://modelscope.cn/datasets/Major-TOM/Core-S2L2A-249k-OlmoEarth) |

> **Note**: SigLIP, FarSLIP, and DINOv2 use RGB-only inputs (B04, B03, B02). SatCLIP, Clay, and OLMoEarth use multi-spectral inputs.

## Usage

```python
import pandas as pd

# Load metadata
meta = pd.read_parquet("metadata_249k.parquet")
print(len(meta), "patches")

# Load image patches from a shard
images = pd.read_parquet("images_249k/part_00001.parquet")
print(images.iloc[0]["B04"].shape)  # (384, 384)
```

## Web Application

Explore these embeddings interactively with the [EarthEmbeddingExplorer](https://modelscope.ai/studios/Major-TOM/EarthEmbeddingExplorer) web application, supporting text, image, and geolocation queries.

## Citation

If you use this dataset, please cite both the EarthEmbeddingExplorer tutorial paper and the original Major-TOM paper:

```bibtex
@article{zheng2026earthembeddingexplorer,
  title={EarthEmbeddingExplorer: A Web Application for Cross-Modal Retrieval of Global Satellite Images},
  author={Zheng, Yijie and Wu, Weijie and Wu, Bingyue and Zhao, Long and Li, Guoqing and Czerkawski, Mikolaj and Klemmer, Konstantin},
  journal={arXiv preprint arXiv:2603.29441},
  year={2026},
  note={ICLR 2026 Workshop ML4RS Tutorial Track (oral)}
}
```

```bibtex
@inproceedings{francis2024majortom,
  title={Major TOM: Expandable Datasets for Earth Observation},
  author={Francis, Alistair and Czerkawski, Mikolaj and others},
  year={2024},
  booktitle={IGARSS 2024},
  eprint={2402.12095},
  archivePrefix={arXiv}
}
```

## License

This dataset is released under the [CC-BY-SA-4.0](https://creativecommons.org/licenses/by-sa/4.0/) license.
