Generally speaking, when we need to select an appropriate data source for a given application, e.g. If you have not yet heard for some of these terms, the post might be challenging to read, but worthwhile if you plan to work in the field. These represent different quantities, and the fact that you might get three different answers to the same question should already cause you some head-scratching. In this post, we will focus on optical satellite imagery (radar imagery is way more complex) and try to shed some light over the most common answers to “What is the spatial resolution?”, which, in order of popularity, are probably pixel size, Ground Sample Distance and Ground Resolved Distance. However, we have noticed some inconsistencies and potentially misleading usages of the term “spatial resolution” which could cause confusion to someone new to the field, and sometimes to experts too. In fact, spatial resolution is the bread and butter of any user of remotely sensed imagery, whether they know it or not, and is often a deciding factor for using one satellite imagery over another for a given application. “What is the spatial resolution of this image?” must be high on the list of most frequently asked questions in Earth Observation (EO) and should definitely make it to the EO bingo card, along with “Can you count cars with it?”, “Can’t you just zoom-in more?” and “Is this a real-time video?”. Special thanks to Miha Kadunc, Maxim Lamare and Grega Milcinski for the invaluable feedback. Written by Devis Peressutti and Matej Batič.

We think we know what it means, but do we really? We wrote the following rant to clarify some confusion and make life easier for our future selves.

The most misunderstood words in Earth Observation

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