1 1 DATA GROUPS MISSING DUE TO RADIO FADING
2 2 DATA GROUPS MISSING DUE TO OUTAGE OF CENTRE
3 3 DATA GROUPS MISSING DUE TO OUTAGE OF CIRCUIT
4 4 NON-IMPLEMENTATION OR MAINTENANCE OF REQUIRED RBSN DENSITY
5 5 SHORTAGE OF QUALIFIED STAFF TO MAN STATIONS
6 6 LACK OF CONSUMABLES
7 7 INSTRUMENT FAILURE
8 8 NON-ADHERENCE TO TELECOMMUNICATION PROCEDURES
9 9 SOME OBSERVING PROGRAMMES CEASED
15 15 MISSING VALUE
