Characteristics of latitude distribution of sunspots and their links to   solar activity in pre-Greenwich data
  We study and compare characteristics of sunspot group latitude distribution in two catalogs: the extended Greenwich (1874--2014) and Schwabe ones (1825--1867). We demonstrate that both datasets reveal similar links between latitude and amplitude characteristics of the 11-year cycle: the latitude dispersion correlates with the current activity and the mean latitude of sunspots in the cycle's maximum is proportional to its amplitude, It agrees with conclusions that we made in previous papers for the Greenwich catalog.   We show that the latitude properties of sunspot distribution are much more stable against loss of observational data than traditional amplitude indices of activity. Therefore, the found links can be used for estimates of quality of observations and independent normalizing of activity levels in a gappy pre-Greenwich data. We demonstrate it using the Schwabe catalog as an example.   In addition, we show that the first part of the Schwabe data probably contains errors in determination of sunspot latitudes that lead to overestimation of the sunspot latitude dispersions. 
V. G. Ivanov and E. V. Miletsky
astro-ph.SR