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# Surface Reflectance Mosaics

![Header Thumbnail](/data/imagery/mosaics/cir.webp)

Mosaics are generated by querying scenes that overlap a specific area of interest within a designated time frame. These scenes are then ranked based on quality metrics metadata, such as the presence of clouds and haze, with the highest quality scenes placed at the top. Using a best-on-top algorithm, the highest quality scenes are efficiently composited to create the final mosaic.

**Normalized Surface Reflectance Mosaics** (Zoom Level 15 – 4.77 meter cell size at the equator) are created using the Ortho Analytic Surface Reflectance imagery asset type ([ortho\_analytic\_4b\_sr/ortho\_analytic\_8b\_sr](https://docs.planet.com/data/imagery/planetscope/psscene.md) ). These mosaics are optimized to reduce the variability due to atmospheric effects, enabling users to perform spectral, quantitative, and time series analyses.

For more details, see the [Mosaics Webpage](https://docs.planet.com/data/imagery/mosaics.md) and the [Mosaic Product Technical Specification](https://assets.planet.com/products/basemap/planet-basemaps-product-specifications.pdf) document.

### Normalized Surface Reflectance Mosaics Product Details

| Source imagery                                     | Download bands | Streaming bands | Monitoring frequency               | Zoom level | Color target                          |
| -------------------------------------------------- | -------------- | --------------- | ---------------------------------- | ---------- | ------------------------------------- |
| PlanetScope Surface Reflectance<br />`analytic_sr` | BGRN           | RBG, CIR        | Weekly<br />Monthly<br />Quarterly | 15         | Sentinel-2<br />None (non-normalized) |