  The Lomb-Scargle periodogram is a well-known algorithm for detecting and
characterizing periodic signals in unevenly-sampled data. This paper presents a
conceptual introduction to the Lomb-Scargle periodogram and important practical
considerations for its use. Rather than a rigorous mathematical treatment, the
goal of this paper is to build intuition about what assumptions are implicit in
the use of the Lomb-Scargle periodogram and related estimators of periodicity,
so as to motivate important practical considerations required in its proper
application and interpretation.
