QUALITY ASSESSMENT OF SEA LEVEL DATA by the UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER JOINT ARCHIVE FOR SEA LEVEL updated: 16 Sep 2013 Station : Takoradi-C Latitude: 04 53.1N Country : Ghana Longitude: 001 44.7W JASL # : 231C Time Meridian: GMT GLOSS # : 335 Originator #: NODC #: 70004101 Contributor : British Oceanographic Data Centre (BODC) Joseph Proudman Building 6 Brownlow Street Liverpool L3 5DA United Kingdom Originator : Survey of Ghana Original Data: digital Instrmnt Type: OTT Kalesto radar sensor 2 x OTT ODS4-K pressure sensor (backup) Digitzd Intvl: 1 or 3 min Present Data : Hourly, daily, and monthly values obtained by: Hourly : unconfirmed Daily : 119-point convolution filter (Bloomfield, 1976) centered on noon applied to the hourly data with respective periods of the 95, 50, and 5% amplitude points at 124.0, 60.2, and 40.2 hours Monthly: Simple average of all daily values; calculated if 7 or fewer days are missing Span of data : 04 Jan 2007 - 08 Sep 2012 Gaps > 1 mon : 14 Aug 2007 - 08 Oct 2007;19 Oct 2007 - 24 Jan 2008 19 Apr 2009 - 25 May 2009;29 May 2009 - 22 Jan 2010 01 Apr 2010 - 13 Mar 2011 Time Refernce: GMT (00-23 hours) Space-filler Flag :-9999 Units : millimeters Missing Data Flag : 9999 Existing : Yes Operational : Yes Sat. Trans. : No Distribution : 2007-2012 Refernce Levl: All data are referred to local Chart Datum. Benchmark Description TGBM GCS BM H4 Main benchmark. Marker on tide gauge, close to radar mount HB TAK 3 Benchmark roughly 10m to the right of the tide gauge SG1 Benchmark roughly 10m to the left of the tide gauge SG2 Near the TKTG GNSS station SGN1 Between tide gauge and harbour entrance, close to a large bldg TKTG Takoradi Tide Gauge GNSS station – 30m from tide gauge SGN9 At harbour entrance SGN3 On entrance of roundabout from the harbour SGW346 In centre of roundabout GPS4C Auxilliary marker of TKRD, close to church SGWH1 Pillar in front of Survey Department of Ghana office SGN4 On left side of stairs of Survey Department of Ghana office GPS1_Roof Marker in roof near TKRD GPS2_Roof Marker in edge of roof near TKRD TKRD GNSS station on roof of Survey Department of Ghana office Datum Relationships: Chart Datum = 3.086m below TGBM GCS BM H4 Chart Datum = 3.292m below HB TAK 3 Chart Datum = 3.357m below SG1 Chart Datum = 3.415m below SG2 Chart Datum = 3.297m below SGN1 Chart Datum = 6.067m below TKTG Chart Datum = 4.179m below SGN9 Chart Datum = 24.943m below SGN3 Chart Datum = 25.042m below SGW346 Chart Datum = 28.288m below GPS4C Chart Datum = 30.427m below SGWH1 Chart Datum = 30.642m below SGN4 Chart Datum = 34.451m below GPS1_Roof Chart Datum = 34.427m below GPS2_Roof Chart Datum = 36.755m below TKRD Comment : 1) BODC notes: Amplitudes and phases of main tidal constituents have been compared with previously calculated values. Records have been visually inspected for spikes, datum shifts and timing errors. 2) JASL: gaps 24 hour or less were interpolated at the JASL. The tide gauge is located at Takoradi harbour, in a tide gauge hut belonging to the Western Region Survey Department. CI MISSING REPLACED GAPS QUESTIONABLE YEAR (%) DATA OR BAD DATA FLUCTUATIONS ---- --- -------------------- --------------- -------------------- 2007 60 25-29,120-122,198- (02)197-(09)197 none 205,226-281,283-285, (18)205-(15)206 292-365 2008 93 1-24,183-185 (23)307-(06)308 none (19)309-(07)310 (22)316-(07)317 (23)317-(08)318 2009 31 109-145,149-365 (21)024-(05)025 none 2010 20 1-22,91-365 (18)061-(14)062 none (12)089-(04)090 2011 80 1-72,88-89 (13)072-(12)073 none 2012 63 175-197 (17)246-(00)247 none (09)247-(16)247 (13)250-(05)251 (08)252-(16)252