2019-06-19 Corrected end date for system 7823
	   Added file changes.log

2019-09-03 Correction: 1874 end date from 2015-01-01 to 2050-01-01
           Correction: 7237 entries from 2009 updated/edited with newest 
           system log info, and let latest epoch be 2050-01-01
           
           These two changes also fix a problem whereby the software provided 
           with these tables did not find valid CoM values for these two 
           stations after 2015 (1874) and 2017 (7237).

2019-11-22 Addition: 8834 IR system (1064 nm)
	   
2019-11-22 com6() subroutine can now return default CoM values even under 
	   error conditions, if variable RETURN_DEFAULT is set to TRUE. Useful 
           to obtain default values for the few stations missing.

2019-12-17 Added Stafford 7865

2020-04-09 Corrected starting epoch for latest 7840 configuration, off by one year
	   Corrected end epoch for previous 8834 (532 nm) system, to include 
	   June 2019, where the station used both systems while the new IR laser 
	   and associated equipment was installed.
	   Updated detector jitter info for PMT H6533, used in the Russian network,
	   using manufacturer's data. NB. CoM values not recomputed at this stage

2020-06-08 Added JiuFeng 7396

2021-03-25 4-month gap in CoM values for 7810@846 nm noted by J.Ries was caused by 
           inconsistencies in the site log dates for timer changes. Gap closed from 
           inspection of NP calibration RMS at 846 and 423 nm. Error incurred: 1 mm 
           difference between default and table values for that period for 846 nm.
	
	   7840 operated with the 12 Hz laser during 2020/07/29 - 2020/09/25.
	   Tables updated using already computed values (same systems)

2021-05-11 Added most important pre-ILRS stations missing from the tables (LAGEOS):
	   7086 McDonald MLRS
           7097 Easter Island TLRS-2 
	   7109 Quincy MOB-8, TLRS-4
           7121 Huahine MOB-1
	   7122 Mazatlan MOB-6, TLRS-4
           7123 Huahine TLRS-2
           7834 Wettzell
	   7907 Arequipa SAO-2

	   Values for the MOBLAS and TLRS systems were assigned as the mean of the 
           entries from similar systems for the pre-1993 period:

	   MOBLAS from 7090 (MOB-5), 7105 (MOB-7), and 7110 (MOB-4)
           TLRS from 7403 (TLRS-3) and 7110 (TLRS-4)
           SAO-2 from Matera SAO system

           Wettzell and McDonald had values already, but they were wrongly assigned to 
           the station IDs used in their modern reincarnations (8834 and 7080). The 
           dates of applicability have been changed accordingly.

           NB. only CoM values for LAGEOS have been added.

2022-09-15 Updates to some stations on the basis of changes in their site logs and a 
        revision of the information available for some others. New station Izaña-1. 
        Affected sites:
        7110, 7124, 7249, 7396, 7701, 7821, 7824, 7838, 7941, 8834

        These updates are minor, although there are a few significant changes for 
        Etalon and Ajisai mostly.

2023-11-28 Added LARES-2.
           Added station 7306 TKBL
           systems.dat: some inactive stations had 2050-01-01 as end date (i.e active)
           systems.dat: fixed end date for 7840 kHz entry from 2014 (of no consequence)
           
           N.B. the files containing the CoM tables have been moved to the directory com.
           If you do not want this you must change the 'com_path' variable in the code.