Auto-correlation analysis was performed using digitized synoptic charts of
photospheric magnetic fields for the past three solar activity cycles (1965
-1994). The obtained correlograms were used to study the rotation and the z
onal-sector structure of large-scale solar magnetic fields all over the obs
ervable region of heliolatitudes in various phases of solar activity. It is
shown that the large-scale system of solar magnetic fields is rather compl
ex and comprises at least three different systems. One is a global rigidly
rotating system. It determines the cyclic variation of magnetic fields and
is probably responsible for the behavior of magnetic fields in the polar zo
nes. Another is a rigidly rotating 4-sector structure in the central (equat
orial and mid-latitude) zone. The third is a differentially rotating system
that determines the behavior of the LSSMF structure elements with a size o
f similar to 30-60 degrees and less. This one is the most noticeable in the
central zone and absent in the polar zones. Various cyclic and rotation pa
rameters of the three field structures are discussed.