Revision of GPR data
The Greenwich data books are available in pdf format at site of the UK Solar System Data Centre (UKSSDC).
They have two types of sections of sunspot group data between 1874 and 1955: the "ledgers" of sunspot groups and the daily "measures" of sunspots and faculae.
This revised version of GPR is created from the electronic version of GPR published at NOAA National Geophysical Data Center (NGDC) based on the ledgers.
That database was compiled by Fred Ward, USAF AFCRL, in the 1960s and later updated by Doug Hoyt in the 1990s.
The basic dataset (1874-1976) consists of files with extension "gpr" which is available at the site of Sunspot region data and
its ftp area .
The additional dataset of Solar White Light Faculae contains detailed daily lists of sunspots (1874-1915) or daily lists of sunspot groups (1916-1955) based on the tables of "measures". The summaries of total daily data are available for 1956-1976. These data were keyed into digital form as part of a data rescue of NOAA starting in 1999.
Concerning "The Greenwich Photo-heliographic Results (1874-1976)" and their digitized datasets see and refer to the following papers:
Erwin E. H., Coffey H. E., Denig W. F., Willis D. M., Henwood R., Wild M. N., 2013, "": Initial Corrections to the Printed Publications, Solar Phys.,
Willis D. M., Coffey H. E., Henwood R., Erwin E. H., Hoyt D. V., Wild M. N., Denig W. F, 2013, "": Summary of the Observations, Applications, Datasets,
Deﬁnitions and Errors, Solar Phys.,
Willis D. M., Henwood R., Wild M. N., Coffey H. E., Denig W. F., Erwin E. H., Hoyt D. V., 2013, "": Procedures for Checking and Correcting the Sunspot
Digital Datasets, Solar Phys.,
We highly appreciate the efforts of the colleagues involved in the projects mentioned above.
List of tests and corrections applied during this revision (Debrecen, 2014)
The main tests were based on the basic files of "gpr" and the additional files called "saf" (spots and faculae) here. These datasets were compared here to eliminate or decrease the discrepancies because of the various typographic errors of the printed or digitized versions.
The list of the checked assertions and the methods applied to resolve the problem after checking errors against the books.
If the any discrepancy cannot be resolved by checking the books, the most probable error was corrected to achieve a consistency within the given threshold.
Revised and converted versions of "gpr" files - ftp access
List of tests
List of modifications
Improved version of "saf" files
Reformatted versions of "saf" files