Planet's imagery is available via Planet Explorer and the Data API. It comes in different 'Item Types' and 'Asset Types'. An item is a single picture taken by a satellite at a certain time. Item's have multiple asset types including the image in different formats, and supporting metadata files. This guide will help you select the right combination for your use case.
How do I filter for the highest quality Planet imagery?
- Filter for satellites in Sun-Synchronous Orbit (SSO). This will give more uniform shadows, and will also indirectly select for our latest 'Planet Scope 2' telescope hardware. To do this set a Ground Sample Distance filter to greater-than 3.6m.
- Download the 'analytic' asset - this is Scaled Top of Atmosphere Radiance calibrated, per-sensor calibrated, and 16-bit.
Are you doing visual-only analysis (e.g. web, or desktop based)?
Select the 'visual' asset. It has an artificial color-curve applied to make it more appealing to the human eye.
Are you performing scientific analysis, or using GIS/RS software?
Select the 'analytic' asset, which is Scaled Top of Atmosphere Radiance calibrated, per-sensor calibrated, and 16-bit. Do not use the 'visual' asset which is only 8-bit, and not Radiance calibrated.
Do you want to use the NIR band, to calculate e.g. NDVI?
Choose Multi-spectral Item Types only (Planet Scope Scene 4-Band, Planet Scope OrthoTile, Rapideye OrthoTile). Then use only the 'analytic', or 'basic_analytic' asset types. Visual assets are not multispectral.
Do you want to do your own orthorectifcation?
Planet uses the term 'basic' to denote unorthorectified. In Planet Explorer select the 'Basic' asset type in the download dialog. The equivalent asset in the Data API is 'basic_analytic'. Apart from orthorectification, 'basic' assets are the same as the 'analytic' asset.
Are you looking for imagery before Mid-2016?
Only the Planet Scope 3 Band and RapidEye OrthoTile Item Types contain imagery before mid-2016.
Can't find 4-band imagery in Scenes Explorer?
Multi-spectral imagery is only available in our new GUI, Planet Explorer, or via the Data API. Note also that the 'analytic' asset served via Scenes Explorer is not Top of Atmosphere Radiance calibrated.
Do you want Top of Atmosphere reflectance for your analysis?
You can find the Reflectance coefficients in the XML metadata asset, named 'radiometricScaleFactor', and 'reflectanceCoefficient'. Multiply pixel values in the GeoTIFF by these coefficients.
What band order does Planet Use?
For any multispectral asset, the order is BGRN. For any 3 band asset, it is RGB.
What about the other asset types I see?
Planet has various non-core asset types only available via the Data API:
- analytic_dn: non-radiometrically calibrated imagery suitable for analytic applications
- udm: image mask file which provides information on areas of unusable data within an image (e.g. cloud and non-imaged areas)
See our Imagery Products Specifications for further information.