To retrieve a preview image for an observation from Helios, simply use the ID of the observation with the Preview method in the Observations API:

https://api.helios.earth/v1/observations/:id/preview

For camera-based observations, the Search and Show methods also return a reference to the previous observation ID. We can therefore quickly obtain its preview image in the same manner:

https://api.helios.earth/v1/observations/:prev_id/preview

When coupled with the previous sensor data values included in each response (see example), these preview images help provide a full understanding of the weather transitions for a location.

Note that while this API call will return an image response for most observations, some observations in the Helios system may be data only records with no preview image available.