On ‘ground’ truth and why we should abandon the term

I make a case to abandon the use of the term “ground truth.” After a brief history
of the term that indicates its military origins, two main arguments are presented against the use
of the term. The first is from measurement theory. The second is by way of presenting three
examples: the first is in crop mapping, in which “ground truth” may have some validity. This
is presented as the exception to prove the rule. The second example looks at albedo, in which
the measurand is the same for the local and remote measurements, and evidence is provided to
support this paper’s argument. The third example looks at the scattering phase center in radar.
In this case, the measurand is different for the local and remote measurements, and an argument
is given for why this does not warrant the use of the term. Finally, a heuristic checklist that
seeks to guide readers to reflect on whether or not their particular field measurements should
be referred to as “ground truth” is provided.