INFORMATION FOR BODC SERIES REF. NO.    41588                  
                         Sea Floor Pressure Gauge Inventory Number :   7045     
 Start Time : 02 Jan 1979 0607 GMT                  Latitude  :  17deg 04.2min S
 End Time   : 25 Mar 1979 0752 GMT                  Longitude : 013deg 39.6min W
 Nominal Cycle Interval   :  900.0 secs         Sensor Depth    :   2700.00m    
                                                Sea Floor Depth :   2700.00m    
 Positional Uncertainty   : 0.1 to 0.5 n.miles                                  
 Depth Datum              : Instantaneous                                       
 Data Category            : Offshore sea floor pressure series                  
 Instrument Type          : Tide gauge (unspecified)                            
 Instrument Mounting      : Sea floor - fixed                                   
 Originator Laboratory    : Proudman Oceanographic Laboratory, Bidston, UK      
 Originator's Identifier  : T7AP0/PDFH4                                         
 Additional information stored with the data:                                   
    Clock gained 5 seconds over 82 days 1 hour 44 minutes 55 seconds; the cycle 
    interval and time values have been corrected.                               
    Instrument Characteristics                                                  
    Station T7                                                                  
    Aanderaa TG-4A                             (BODC Series Ref. 41588)         
    Nominal sampling interval       900 seconds                                 
    Integration period               30 seconds                                 
    This instrument was deployed on the same frame as a Mark IV tide gauge.     
    I.O.S. Data Processing of Off-Shore Pressure Recorder Data 3                
    Data processing comprises 2 stages:-                                        
    1. Instrumental drift and depth are removed, thus the drift free series  is 
       produced with an artificial mean of zero.                                
    2. Generally the pressure values have  been  obtained  by  integration  and 
       averaging  over  the  sampling  interval, followed by logging; hence the 
       time value assigned to a data cycle has been  chosen  as  the  mid-point 
       between  the  start and end time of each interval. Some pressure records 
       have been sample rate reduced from the basic time step of  the  recorder 
       to  produce  either hourly or 15 minute values, incorporating any timing 
       corrections due to clock error.                                          
 The following additional documents apply to this series:                       
  27823; Aanderaa Pressure Recorder Type TG-4A