By Ms R. FARRE BSC SEA EGS SUPERINTENDENT TIDAL INFORMATION SOUTH AFRICAN NAVY HYDROGRAPHIC OFFICE...

By Ms R. FARRE BSC SEA EGSSUPERINTENDENT TIDAL INFORMATION

SOUTH AFRICAN NAVY HYDROGRAPHIC OFFICE

OTT “KALESTO” RADAR TIDE GAUGE

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AIM

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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

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RSA TIDE GAUGE NETWORK

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LEVELING THE TRANSDUCER

THE TRANSDUCER NEEDS TO BE LEVELLED ON THE DAVIT Spirit level

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Surveying and Calibration Benchmarks How to survey in a Tide Gauge Davit LOGOSENS reference level Long and short stay


SCOPE: RSA Tide Gauge Network Leveling the Transducer

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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 = 0Anything above MSL is height or elevationAnything 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

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SO A BENCHMARKS HEIGHT CAN BE CONVERTED TO A HEIGHT ABOVE CD Height of benchmark above

MSL + CD for the port A + C = B

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IDENTIFY BENCHMARKS AND CHECK THEIR LOCATION WITH A SITE MAP (left)

BENCHMARK HEIGHTS CAN BE OBTAINED FROM LAND SURVEYOR TOWN PLANNERS

OFFICE

WF9 = MSL + 2.331mWF10 = MSL + 2.343mNEW GPS = MSL + 2.329m

Light

W F 8

NO

RT

H S

PU

R

New GP S

W F 9

W F 10

'A ' BERTH

N

TideGauge

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THE TRIPOD, WITH DUMPY, MUST BE POSITIONED ½ WAY BETWEEN EACH BENCHMARK.

THE TACH STAFF WILL BE PLACED ON THE BENCHMARK STUD

STUD

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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

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YOU STAND AT 1 ASSISTANT AT 1

Take readings YOU TURN, WITHOUT

MOVING THE TRIPOD, TO 2

ASSISTANT MOVES TO 2 Take readings

YOU MOVE TO 2 ASSIATANT STAYS AT 2,

TURNING TO FACE YOU WITHOUT LIFTING THE TACH STAFF OFF THE BENCHMARK STUD

Take readings.

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YOU TURN, WITHOUT MOVING THE TRIPOD, TO 3


YOU MOVE TO 3 ASSISTANT STAYS AT 3,

TURNING TO FACE YOU WITHOUT LIFTING THE TACH STAFF OFF THE BENCHMARK STUD

Take readings.

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YOU TURN, WITHOUT MOVING THE TRIPOD, TO 4


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

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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)

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EXAMPLE OF SURVEY RESULTS FOR RICHARDS BAY, Northern Kwazulu Natal

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MEASUREMENTS OF THE “KALESTO” RADAR GAUGE

FROM TOP OF “BLACK BOX” TO THE TRANSDUCER FACE (Tx) IS 0.400m

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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 -0.400

Ref face above MSL 4.0861 4.0852

Add CD 1.015 1.015

Ref face above CD = 5.1011 5.1002

Av ht of ref face above CD = 5.101

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“KALESTO” RADAR GAUGE IN SITU (Richards Bay)

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“KALESTO” RADAR GAUGEPLATFORM FOR EASY ACCESS TO GAUGE DURING LEVELING AND

CALIBRATION. (Richards Bay)

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CALIBRATION OF “KALESTO”

Knysna

Simon’s Town

Richard’s Bay

East London

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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 + 3.422

(D-B) = + 1.063

less E to Tx = - 0.400

Ref Face =MSL + 4.085

CD =MSL - 1.015

+5.100

Ht of Tx = 5.100m above CD

readings @ short stay:

5.100 - (2.750 - 0.400) = 2.750m readings @ long stay:

5.100 - (3.750 - 0.400) = 1.750m

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Program the reference level into the LOGOSENSWith RS232 cableCreate station in the

office before departure to the installation site.

Show how this is done with WBSLAO program

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AT SHORT STAY:From 1300B to 1900BNo values: 125Mean: 1.715m above CDThis is 0.035m LOW

ADD 0.035m to ref in LOGOSENS

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AT LONG STAY:From 1925B to 0900B

next dayNo values: 272Mean: 2.718m above CDThis is 0.032m LOW

ADD 0.032m to ref in LOGOSENS

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After resetting the reference level in the LOGOSENS

AT LONG STAY:From 0935B to 0955B No values: 7Mean: 2.753m above CDThis is 0.003m HIGH

This 3mm is perfectly acceptable to be out by.

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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.

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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 programCheck accuracy of your predictions

Overlay actual and predictionsCan pick up time/ clock errors timeously

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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


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EXAMPLES OF HYDRAS3 GRAPHICS

NO POWER, BATTERY HAS NOT “KICKED” INData lost.

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NO POWER, BATTERY HAS NOT “KICKED” INData lost. Clock stopped data out

of phase

RESET CLOCK IMMEDIATELY!

DATA WILL HAVE TO BE MOVED BACK INTO PHASE

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TO REST THE CLOCKSelect refreshSelect set date/time

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PREDICTIONS vs ACTUALS FOR DURBAN

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MULTIPLE GRAPHICS

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MULTIPLE GRAPHICS

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QUESTIONS?

By Ms R. FARRE BSC SEA EGS SUPERINTENDENT TIDAL INFORMATION SOUTH AFRICAN NAVY HYDROGRAPHIC OFFICE...

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Transcript of By Ms R. FARRE BSC SEA EGS SUPERINTENDENT TIDAL INFORMATION SOUTH AFRICAN NAVY HYDROGRAPHIC OFFICE...