The Daya Bay Reactor Neutrino Experiment The Alignment Measurement for The Daya Bay Reactor Neutrino Detector Accelerator center of IHEP Luo tao 2010.9.12.

The Daya Bay Reactor Neutrino Experiment

The Alignment Measurement for The Alignment Measurement for The Daya Bay Reactor Neutrino The Daya Bay Reactor Neutrino DetectorDetector

Accelerator center of IHEPAccelerator center of IHEPLuo tao Luo tao

2010.9.122010.9.12



• ContentContent

1.Introduction1.Introduction

2.Simulation2.Simulation

3.The alignment measurement with 3.The alignment measurement with GPSGPS

4.The data processing4.The data processing

5.Analysis5.Analysis

6.Conclusion6.Conclusion


Introduction of the Alignment Introduction of the Alignment MeasurementMeasurement

• The distance between The distance between neutrino detector and neutrino detector and Daya bay reactor is Daya bay reactor is measured in this measured in this survey.survey.

In this picture, the line In this picture, the line is the outside control is the outside control network for GPS network for GPS surveysurvey


• Simulation (1)Simulation (1)• The simulation is based on The simulation is based on

Monte Carlo method. Monte Carlo method.

• There are two control points There are two control points for tunnel entrance, six control for tunnel entrance, six control points for the Daya bay points for the Daya bay reactor and one used for reactor and one used for transferring in this GPS control transferring in this GPS control network shown in fig.1.network shown in fig.1.

• The red ellipses represent the The red ellipses represent the error circles after simulation error circles after simulation such as shown in fig.2.such as shown in fig.2.

1

2


• Simulation (2)Simulation (2)• The detail results for correcting The detail results for correcting

value and error ellipse (unit: mm)value and error ellipse (unit: mm)

• Name MX MY MP E FName MX MY MP E F

• M5 3.76 3.96 5.46 4.01 3.7M5 3.76 3.96 5.46 4.01 3.7

• M9 4.59 4.70 6.57 4.78 4.5M9 4.59 4.70 6.57 4.78 4.5

• P1 3.63 3.79 5.25 3.94 3.46P1 3.63 3.79 5.25 3.94 3.46

• P2 4.27 3.84 5.74 4.37 3.73P2 4.27 3.84 5.74 4.37 3.73

• P3 4.68 4.71 6.64 4.87 4.52P3 4.68 4.71 6.64 4.87 4.52

• P4 4.9 4.87 6.91 4.91 4.87P4 4.9 4.87 6.91 4.91 4.87

• P5 5.07 5.23 7.29 5.24 5.07P5 5.07 5.23 7.29 5.24 5.07

• P6 5.17 5.31 7.41 5.36 5.12P6 5.17 5.31 7.41 5.36 5.12


• The GPS receiver is used in this simulation. Rang The GPS receiver is used in this simulation. Rang precision is 5mm+2ppm, angle precision is 1.6 precision is 5mm+2ppm, angle precision is 1.6 secsec

• Conclusion: high precision can be achieved Conclusion: high precision can be achieved through this scheme, superior to 10 mmthrough this scheme, superior to 10 mm

• Simulation (3)Simulation (3)


• The GPS survey experiment under the high voltage The GPS survey experiment under the high voltage wire (220 KV) has shown that it could be feasible. etcwire (220 KV) has shown that it could be feasible. etc

• The Alignment Measurement with GPS (1)The Alignment Measurement with GPS (1)


• There are some compared baselines measured by botThere are some compared baselines measured by both GPS receivers and total-stations under the high volth GPS receivers and total-stations under the high voltage wire as well as others (launch tower, near buildinage wire as well as others (launch tower, near building) g)

• Small difference has been discovered after comparisoSmall difference has been discovered after comparison between both method, measurements with GPS recn between both method, measurements with GPS receivers are not effected.eivers are not effected.

• The distance between GPS receivers and building depThe distance between GPS receivers and building depends on the heights of building (e.g. ends on the heights of building (e.g. 5 meters away 5 meters away from 20-meter-high building, almost from 20-meter-high building, almost 15 degree’s 15 degree’s altitude angle)altitude angle)

• The alignment measurement with GPS (2)The alignment measurement with GPS (2)


• 4 GPS receivers are applied in this alignment, 4 GPS receivers are applied in this alignment, Topcon and SokkiaTopcon and Sokkia

• Every tunnel entrance and two reactor core has 4 Every tunnel entrance and two reactor core has 4 GPS control points, and 4 extra control points are GPS control points, and 4 extra control points are only used to transfer.only used to transfer.

• The 2-hour observations have been done at The 2-hour observations have been done at tunnel entrance, as well as reactor core. Then the tunnel entrance, as well as reactor core. Then the others is totally 4-hours.others is totally 4-hours.

• The Alignment Measurement with GPS (3)The Alignment Measurement with GPS (3)


• The GPS observation shown in fig.1.2, and the The GPS observation shown in fig.1.2, and the measurement scheme shown in fig.3measurement scheme shown in fig.3

• The alignment measurement with GPS (4)The alignment measurement with GPS (4)

31

2


• The data preprocessingThe data preprocessing

• The GPS measurement is The GPS measurement is based on its antenna based on its antenna phase center, and could be phase center, and could be transferred to the marked transferred to the marked points or the forced points or the forced centering observation centering observation stand by slant height or stand by slant height or vertical height which is vertical height which is measured like fig.1.2.measured like fig.1.2.

rabbetGPS antenna

Marked poi nts

Sl ant hei ght

• The Data Processing (1)The Data Processing (1)

Vert i cal hei ght

rabbetGPS antenna

Forced centeri ng observati on stand

1 2


• The GPS baseline calculationThe GPS baseline calculation

• The GPS baseline is a 3-D The GPS baseline is a 3-D coordinate difference every two coordinate difference every two GPS receivers by difference GPS receivers by difference measuring such as fig.1measuring such as fig.1

• There are several kinds of There are several kinds of difference measuring like fig.2difference measuring like fig.2


1

2


• The statistical results for GPS baseline calculationThe statistical results for GPS baseline calculation• The RMS (root mean square) is a entire precision The RMS (root mean square) is a entire precision

index like formula.2,“f” is a number for redundant index like formula.2,“f” is a number for redundant observations.observations.

• The RATIO is a ratio with the minimum RMS and The RATIO is a ratio with the minimum RMS and weak minimal RMS, and should be more than 1.weak minimal RMS, and should be more than 1.

• The reference variable should be 1 when the The reference variable should be 1 when the adjusted data is consistent with site observations.adjusted data is consistent with site observations.

ratioratio Reference Reference variablevariable

RMSRMS

The bestThe best 1.71.7 0.5340.534 0.0020.002

The poorestThe poorest 116.116.44

7.5367.536 0.0090.009

averageaverage 18.118.1 5.85.8 0.0040.004

Standard Standard deviationdeviation

26.026.0 2.42.4 0.00450.0045


f

PVVRMS

T

1

2

SEC

MIN

RMSRATIO

RMS

f

PVVRMS

T


• The error of closureThe error of closure

• The GPS loop includes the simultaneous loop and The GPS loop includes the simultaneous loop and the asynchronous loop.the asynchronous loop.

• The simultaneous loop composes of GPS baseline The simultaneous loop composes of GPS baseline measured at the same time, and asynchronous measured at the same time, and asynchronous loop is not all measured . loop is not all measured .

• It is important for asynchronous loop closure to It is important for asynchronous loop closure to check the GPS observation error, setting point check the GPS observation error, setting point error and etc.error and etc.



• The statistical results for GPS closure errorThe statistical results for GPS closure error


Unit: mmUnit: mm horizontahorizontall

verticalvertical

The bestThe best 0. 10. 1 -1.11-1.11

The poorestThe poorest 4.684.68 99

averageaverage 1.831.83 -1.49-1.49


1.261.26 5.385.38


• The unrestrained adjustment The unrestrained adjustment

• This adjustment can just decide the geometry of This adjustment can just decide the geometry of GPS control network, and should not change its GPS control network, and should not change its scale and azimuth.scale and azimuth.

• It only depends on the GPS baseline for that GPS It only depends on the GPS baseline for that GPS control network precisioncontrol network precision



• The constraint adjustmentThe constraint adjustment

• The known data should be introduced into this The known data should be introduced into this constraint adjustment after unrestrained constraint adjustment after unrestrained adjustment. So the data could change the GPS adjustment. So the data could change the GPS control network’s scale and azimuth as it is control network’s scale and azimuth as it is enough enough

• Firstly the fundamental known data could Firstly the fundamental known data could determine the network in WGS84 (World determine the network in WGS84 (World Geodesic System). Then the control network Geodesic System). Then the control network should be transferred to on the Geoid by precise should be transferred to on the Geoid by precise triangle levelling results.triangle levelling results.



• The statistical results for adjustment in the The statistical results for adjustment in the WGS 84WGS 84


Unit: mmUnit: mm BB LL HH

The bestThe best 0.680.68 0.660.66 0.3430.343

The poorestThe poorest 2.032.03 2.32.3 18.2318.23

averageaverage 0.990.99 0.990.99 6.936.93


1.051.05 1.061.06 7.757.75


• The precise triangle levelling measurementThe precise triangle levelling measurement• It’s feasible and valuable to replace the first order levellIt’s feasible and valuable to replace the first order levell

ing by precise triangle levelling surveying shown as fig.1.ing by precise triangle levelling surveying shown as fig.1.

• It’s measured like formula.1, It’s measured like formula.1, • ““R” - the average earth radius,R” - the average earth radius,• ““k” - the atmospheric dioptre, k” - the atmospheric dioptre, • ““p” - the spherical aberration correction, p” - the spherical aberration correction, • ““r” - the atmospheric dioptre correction.r” - the atmospheric dioptre correction.


1

2

2

2

tan

1 / 2

/ 2

/ 2

ABh D i v f

f p r k D R

p D R

r k D R

1


• The value’s effect of ‘p’ and ‘r’ could almost be offset by The value’s effect of ‘p’ and ‘r’ could almost be offset by reciprocal observation at the same time. reciprocal observation at the same time.

• The following is some experimental contrasting results The following is some experimental contrasting results between precise triangle levelling and geometric levelling between precise triangle levelling and geometric levelling shown as table in addition.shown as table in addition.

• The value with ‘*’ means the average length of closing graphic.The value with ‘*’ means the average length of closing graphic.


Section (unit: Section (unit: m)m)

Baseline’s Baseline’s lengthlength

The height for precise The height for precise triangle levellingtriangle levelling

The height for The height for geometric geometric levelling levelling

differendifferencece

SG004-SG004-SG002SG002

131131 -6.119418-6.119418 -6.118565-6.118565 -0.000853-0.000853

SG002-SG002-DG001DG001

190190 5.2616035.261603 5.262465.26246 0.0008570.000857

SG002-SG002-TM021TM021

489489 21.657421.6574 21.6597721.65977 -0.002368-0.002368

TM021-TM021-CZ002CZ002

*848*848 14.502114.5021 14.5031114.50311 0.001010.00101


• The black line is constraint condition with precise triangle levelling height, the The black line is constraint condition with precise triangle levelling height, the red line will be used to check the results that have been transferred on to the red line will be used to check the results that have been transferred on to the Geoid.Geoid.



• The GPS network is transferred by the black lines. The The GPS network is transferred by the black lines. The red line will check it and the results is shown as below.red line will check it and the results is shown as below.

• The distal GPS network’s precision is better than 10mmThe distal GPS network’s precision is better than 10mm


Section (unit: Section (unit: m)m)

Baseline’s Baseline’s lengthlength

The GPS The GPS height on the height on the

GeoidGeoid

The height for The height for geometric geometric levellinglevelling

differendifferencece

SG004-SG002SG004-SG002 131131 -6.10868-6.10868 --6.1185656.118565

0.0098850.009885

DG001-DG001-TM021TM021

300300 16.407116.4071 16.3990216.3990222

0.0080780.008078

TM021-CZ002TM021-CZ002 *848*848 14.502114.5021 14.5031114.50311 -0.00101-0.00101


• 1. The GPS data processing has a good precision. 1. The GPS data processing has a good precision.

• 3-D precision: mm3-D precision: mm

• 2. The results of precise triangle levelling is close to the 2. The results of precise triangle levelling is close to the geometric levelling, so it may replace the first order geometric levelling, so it may replace the first order levelling as the conditions are enough.levelling as the conditions are enough.

• 3. The GPS coordinate in WGS84 could be transferred on to 3. The GPS coordinate in WGS84 could be transferred on to the Geoid by the precise triangle levelling, and this the Geoid by the precise triangle levelling, and this transferred results is better than 10mm.transferred results is better than 10mm.

• The AnalysisThe Analysis

2 2 21.05 1.06 7.75 7.89


• 1. The precision of GPS control network in the Daya 1. The precision of GPS control network in the Daya Bay reactor neutrino’s alignment is better than Bay reactor neutrino’s alignment is better than 10mm in 3-D coordinate system (almost plane: 10mm in 3-D coordinate system (almost plane: 1mm height: 7mm).1mm height: 7mm).

• 2. The precise triangle levelling is good enough to 2. The precise triangle levelling is good enough to substitute for the first order levelling as that substitute for the first order levelling as that conditions are enoughconditions are enough

• 3. The data in WGS84 could be transferred on to 3. The data in WGS84 could be transferred on to the Geoid by height from precise triangle levelling.the Geoid by height from precise triangle levelling.

• The Conclusion (1)The Conclusion (1)


• Proposals on the alignmentProposals on the alignment

• 1. The 3-D distance could be calculated by both the 1. The 3-D distance could be calculated by both the same coordinate system and analysis method.same coordinate system and analysis method.

• 2. The precise triangle levelling experiment are 2. The precise triangle levelling experiment are enough to get a comprehensive results comparing enough to get a comprehensive results comparing with the geometric levelling.with the geometric levelling.

• 3. This conditions which should transfer it on to the 3. This conditions which should transfer it on to the Geoid could expand to large area.Geoid could expand to large area.

• The Conclusion (2)The Conclusion (2)


• Thanks Thanks

The Daya Bay Reactor Neutrino Experiment The Alignment Measurement for The Daya Bay Reactor Neutrino Detector Accelerator center of IHEP Luo tao 2010.9.12.

Documents

gps survey experiment

gps survey slide

gps control network

gps receivers

high precision

conclusion slide

control points

alignment measurement