1. GLOSS Training Workshop Course Japan Meteorological Agency May 15-26, 2006 Sea Level Data Processing with SLPR2 1. Calibration

2. Calibration Sources * Geodetic surveys *Tide staff readings * Other independent measurement for comparison

3. SLPR2 Calibration Procedure Manual 5.2 Notes: 1. Typically performed one month at a time 2.Utilizes quasi-daily tide staff readings 3. Requires building data files

4. SLPR2 Calibration Procedure Manual 5.2 Step 1. Create a PAIR file (pair = tide staff reading and corresponding tide gauge data value) Appendix D.4 Filename= XSSSYYMM.DAT X: fixed, always “X” SSS: 3-digit station number YY: Year MM: Month Place in directory \slpr2\cal

5. SLPR2 Calibration Procedure Appendix D.4 Sample Pair File: STATION 30 SANTA CRUZ 01 JUL - 01 AUG 1988 250 250 1281 330 330 1373. 570 570 1602 360 360 1400 9999999999999

6. SLPR2 Calibration Procedure Step 2. Plot PAIR file \slpr2\plot\SCAT.EXE Output file R17.OUT (Appendix D.5) Throw out bad pairs then rerun SCAT Delete R*.OUT prior to next run of SCAT.EXE Manual 5.2

7. Example of Corrupted Tide Gauge Data

8. SLPR2 Calibration Procedure Manual 5.2 Step 3. Determine Preliminary Calibration Constant Run \slpr2\QC\REFLEV.EXE Appendix D.6 STATION 30 SANTA CRUZ 01 JUL - 01 AUG 1988 MEAN OF HIGH VALUES : 489 MEAN OF LOW VALUES : 489 MEAN OF HIGH AND LOW MEANS : 489 MEAN OF GAUGE VALUES : 1525 CALIBRATION LEVEL : 1036 NUMBER OF OBSERVATIONS : 32 GAUGE - STAFF(AVE) STANDARD DEVIATION : 8 MEAN ZERO REFERENCE LEVEL VALUE: 1036

9. SLPR2 Calibration Procedure Appendix D.7 Step 4. Build Log File (within \slpr2\cal) MEAN ZERO DATES REFERENCE LEVEL NUMBER OF VALUE (units=feet*) OBSERVATIONS 01 JAN - 01 FEB 1988 1036 32 01 FEB - 01 MAR 1988 1037 28 01 MAR - 01 APR 1988 1035 26 01 APR - 01 MAY 1988 1036 30 01 MAY - 01 JUN 1988 1037 32 Choose a single calibration constant to represent an extended period of time without obvious changes to gauge, tide staff, or tide station foundation Assume month to month variations in the Mean Zero Reference Level Value are associated with uncertainty in the tide staff readings.

10. SLPR2 Calibration Procedure Reference level shift causes: 1.Reprogram or physically readjust the tide gauge zero (change float, new cable, etc) *most common 2. Change tide staff 3. Station foundation change (pier hit by barge)

11. SLPR2 Calibration Procedure Manual 5.2, page 23-24 How to handle a reference level shift Step 1. Identify the time/date of shift (technician reports, data) Step 2. Create pair files for month with the shift separated for periods before and after the shift Step 3. Run SCAT.EXE, weed out bad pairs, run SCAT again Step 4. Run REFLEV.EXE for before and after periods Step 5. The difference between the before and after is the reference level correction constant. Step 6. Apply to data by using COREF.EXE, requires text editing of data files