An Etymological Dictionary of Astronomy and Astrophysics

1. (v.) To sweep a surface with a beam of light or electrons in order to reproduce or transmit a picture.
   In radar, to sweep an airspace or region with a succession of directed beams from a radar aerial system.
   
2. (n.) An act or instance of scanning. The image or display so obtained.

Etymology (EN): M.E. scannen, from L.L. scandere “to read or mark so as to show metrical structure,”
originally, in classical L., “to climb” (the connecting notion is of the rising and falling rhythm of poetry), from PIE *skand- “to spring, leap” (cf. Skt. skandati “he jumps;” Gk. skandalon “a snare, trap, stumbling block;” O.Ir. scendim “I jump”).

Etymology (PE): Rajrub, literally “sweeping along rows,” from raj “row, line”

• rub “to sweep.” The first component raj, variants raž, rak, râk, rezg (Lori), ris, risé, radé, rasté, râsté, related to râst “right, true; just, upright, straight,” → row, → right.

The second component rub stem of rubidan, ruftan “to sweep,” related to robudan “to rub, carry off;” Mid.Pers. rôb- “to rub, sweep, attract;”
Av. urūpaiieinti “to cause racking pain(?);” cf. Skt. rop- “to suffer from abdominal pain,” rurupas “to cause violent pain,” ropaná- “causing racking pain,” rópi- “racking pain;” L. rumpere “to break;” O.E. reofan “to break, tear.”