1. OTT “KALESTO” RADAR TIDE GAUGE
By Ms R. FARRE BSC SEA EGS
SUPERINTENDENT TIDAL INFORMATION
SOUTH AFRICAN NAVY HYDROGRAPHIC OFFICE

2. AIM

3. SCOPE: RSA Tide Gauge Network Leveling the Transducer
Surveying and Calibration
Benchmarks
How to survey in a Tide Gauge
Davit
LOGOSENS reference level
Long and short stay
HYDRAS3
WBSLAO – LOGOSENS operating program

4. RSA TIDE GAUGE NETWORK

5. LEVELING THE TRANSDUCER
THE TRANSDUCER NEEDS TO BE LEVELLED ON THE DAVIT
Spirit level

6. SCOPE: RSA Tide Gauge Network Leveling the Transducer
Surveying and Calibration
Benchmarks
How to survey in a Tide Gauge
Davit
LOGOSENS reference level
Long and short stay
HYDRAS3
WBSLAO – LOGOSENS operating program

7. SURVEYING AND CALIBRATION
AFTER INSTALLATION:
Gauge must be levelled into local benchmark network and a reference level programmed into the logosens.
Must know
Exact height of benchmarks above LLD
what LLD is.
IN RSA LLD = MSL = 0
Anything above MSL is height or elevation
Anything below MSL is a depth.
THUS BENCHMARKS ARE HEIGHTS ABOVE MSL
CD IS LAT  CD IS VALUE BELOW MSL
Durban CD is MSL – 0.913

8. SURVEYING AND CALIBRATION
SO A BENCHMARKS HEIGHT CAN BE CONVERTED TO A HEIGHT ABOVE CD
Height of benchmark above MSL + CD for the port
A + C = B

9. SURVEYING AND CALIBRATION
IDENTIFY BENCHMARKS AND CHECK THEIR LOCATION WITH A SITE MAP (left)
BENCHMARK HEIGHTS CAN BE OBTAINED FROM
LAND SURVEYOR
TOWN PLANNERS OFFICE
WF9 = MSL m
WF10 = MSL m
NEW GPS = MSL m

10. SURVEYING AND CALIBRATION
THE TRIPOD, WITH DUMPY, MUST BE POSITIONED ½ WAY BETWEEN EACH BENCHMARK.
THE TACH STAFF WILL BE PLACED ON THE BENCHMARK STUD
STUD

11. SURVEYING AND CALIBRATION
SURVEYOR STANDS AT POSITIONS 1, 2 & 3
PERSON HOLDING THE TACH STAFF PLACES IT ON THE BENCHMARKS MARKED 1, 2, 3 & ON THE TIDE GAUGE TRANSDUCER AT 4

12. SURVEYING AND CALIBRATION
YOU STAND AT 1
ASSISTANT AT 1
Take readings
YOU TURN, WITHOUT MOVING THE TRIPOD, TO 2
ASSISTANT MOVES TO 2
YOU MOVE TO 2
ASSIATANT STAYS AT 2, TURNING TO FACE YOU WITHOUT LIFTING THE TACH STAFF OFF THE BENCHMARK STUD
Take readings.

13. SURVEYING AND CALIBRATION
YOU TURN, WITHOUT MOVING THE TRIPOD, TO 3
ASSISTANT MOVES TO 3
Take readings
YOU MOVE TO 3
ASSISTANT STAYS AT 3, TURNING TO FACE YOU WITHOUT LIFTING THE TACH STAFF OFF THE BENCHMARK STUD
Take readings.

14. SURVEYING AND CALIBRATION
YOU TURN, WITHOUT MOVING THE TRIPOD, TO 4
ASSISTANT MOVES TO 4
Take readings
Repeat this process “LEAP-FROGGING” back to where you will be taking reading with the tach staff on position 1
IF CORECTLY DONE:
Forward = Backward
 Forward Readings –
 Backward Readings = 0

15. SURVEYING AND CALIBRATION
WHEN PLACING THE TACH STAFF ON THE TRANSDUCER
Always place it on the “black box”
Never on the bracket.
YOU CAN GET THE STD TACH STAFF (1)
Graduations that can be read off manually
AND THE ELECTRONIC TACH STAFF (2)
Barcoded
(2)
(1)

16. SURVEYING AND CALIBRATION
EXAMPLE OF SURVEY RESULTS
FOR RICHARDS BAY,
Northern Kwazulu Natal

17. MEASUREMENTS OF THE “KALESTO” RADAR GAUGE
FROM TOP OF “BLACK BOX” TO THE TRANSDUCER FACE (Tx) IS 0.400m

18. SURVEYING AND CALIBRATION

19. SURVEYING AND CALIBRATION RICHARDS BAY
SCH3
SAN84,2
Ht of above MSL
3.429
3.422
+  to TG
1.0571
1.0632
- less; to ref face
-0.400
 Ref face above MSL
4.0861
4.0852
Add CD
1.015
 Ref face above CD =
5.1011
5.1002
 Av ht of ref face above CD = 5.101

20. “KALESTO” RADAR GAUGE IN SITU (Richards Bay)

21. “KALESTO” RADAR GAUGE PLATFORM FOR EASY ACCESS TO GAUGE DURING LEVELING AND CALIBRATION. (Richards Bay)

22. CALIBRATION OF “KALESTO”
East London
Knysna
Richard’s Bay
Simon’s Town

23. CALIBRATING THE “KALESTO” RADAR GAUGE
Example of a calculation for check calibration of radar gauge, if
A= 3.422m (known value for local benchmark)
Av. A above CD = Av B
Av A =MSL
 (D-B) =
less E to Tx =
 Ref Face =MSL
CD =MSL
+5.100
 Ht of Tx = 5.100m above CD
Can be done using info availablve before departure from survey office and that value programmed into logosens
short stay:
( ) = 2.750m
 long stay:
( ) = 1.750m

24. CALIBRATING THE “KALESTO” RADAR GAUGE
Program the reference level into the LOGOSENS
With RS232 cable
Create station in the office before departure to the installation site.
Show how this is done with WBSLAO program

25. CALIBRATING THE “KALESTO” RADAR GAUGE
AT SHORT STAY:
From 1300B to 1900B
No values: 125
Mean: 1.715m above CD
This is 0.035m LOW
ADD 0.035m to ref in LOGOSENS

26. CALIBRATING THE “KALESTO” RADAR GAUGE
AT LONG STAY:
From 1925B to 0900B next day
No values: 272
Mean: 2.718m above CD
This is 0.032m LOW
ADD 0.032m to ref in LOGOSENS

27. CALIBRATING THE “KALESTO” RADAR GAUGE
After resetting the reference level in the LOGOSENS
AT LONG STAY:
From 0935B to 0955B
No values: 7
Mean: 2.753m above CD
This is 0.003m HIGH
This 3mm is perfectly acceptable to be out by.

28. CALIBRATING THE “KALESTO” RADAR GAUGE
This is how the previous information would be displayed once it is downloaded for a longer period of time.
Calibration records are digitally stored in this method.

29. SOME USEFUL TIPS Always print weekly graphics.
Errors can be noted and corrected timeously
Battery not working
No power
Telephone lines down
Assists with analysis of tides
Shows “spikes” very clearly.
Insert your predictions into the HYDRAS3 program
Check accuracy of your predictions
Overlay actual and predictions
Can pick up time/ clock errors timeously

30. OTT “KALESTO” RADAR TIDE GAUGE
SCOPE:
RSA Tide Gauge Network
Leveling the Transducer
Surveying and Calibration
Benchmarks
How to survey in a Tide Gauge
Davit
LOGOSENS reference level
Long and short stay
HYDRAS3
WBSLAO – LOGOSENS operating program

31. EXAMPLES OF HYDRAS3 GRAPHICS
NO POWER, BATTERY HAS NOT “KICKED” IN
Data lost.

32. EXAMPLES OF HYDRAS3 GRAPHICS
NO POWER, BATTERY HAS NOT “KICKED” IN
Data lost.
Clock stopped data out of phase
RESET CLOCK IMMEDIATELY!
DATA WILL HAVE TO BE MOVED BACK INTO PHASE

33. EXAMPLES OF HYDRAS3 GRAPHICS
TO REST THE CLOCK
Select refresh
Select set date/time

34. EXAMPLES OF HYDRAS3 GRAPHICS
PREDICTIONS vs ACTUALS FOR DURBAN

35. MULTIPLE GRAPHICS

36. MULTIPLE GRAPHICS

37. QUESTIONS?