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A Construction of An Advanced Measuring System

for Astro-Geodetic Determinations

Vukan OgrizovicFaculty of Civil Engineering

Chair for Geodesy and Geoinformatics

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Astro-geodetic geoid

• Vertical deflection

cos

• Geoid undulation difference

B

AdsdN sincos

Astronomical levelling

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Observation ofzenith stars

• For a zenith star:

LASTGAST

tLAST 0

GASTz

z

• Co-ordinates of the zenith:

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Connecting scheme

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Components of the measuring system

• Optical instrument• Snapshot acquisition• Time keeping

software integration

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Optical instrument

• Zeiss Zenitlot PZL-100• Direction of vertical - 2”• Magnification 30x• Compensator

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Snapshot acqusition

• Kodak KAI-2020M• TI TC-237H• 1600 px x 1200 px• 7,4 m x 7,4 m• 11,8 mm x 8.9 mm• CCDOPS

SBIG ST-2000XMC

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Time keeping

• SiRF LX/I• 12 L1 channels• 1PPS• 2 serial ports

notebook

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Results - Face I Iteration 1 2 3 4 5

xi0 -0,39193 -0,09498 -0,00094 0,00481 0,00054

eta0 0,30169 -0,07087 -0,00532 0,00315 0,00062

Phi 0,7874369 0,7874318 0,7874314 0,7874316 0,7874317

Lambda 0,3716323 0,3716225 0,3716224 0,3716229 0,3716230

DPhi["] 4,525 -1,063 -0,080 0,047 0,009

DLambda["] -8,331 -2,019 -0,020 0,102 0,011

A -0,41076 -0,27311 -0,27300 -0,27300 -0,27300

B 0,08253 0,05657 0,05616 0,05609 0,05612

C 119,31582 78,13306 78,45706 78,56605 78,56783

D 0,06542 0,04319 0,04308 0,04310 0,04311

E 0,39273 0,26261 0,26190 0,26195 0,26198

F -77,33344 -52,03102 -52,27364 -52,21987 -52,21525

K -0,00004 0,00001 0,00000 0,00000 -0,00001

L 0,00062 0,00011 0,00038 0,00039 0,00039

s0 1,10100 0,90136 0,98135 0,95443 0,95383

F 1,21 1,23 1,04 1,10 1,10

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Results - Face 2 Iteration 1 2 3 4 5

xi0 -0,43461 0,08852 -0,06188 0,02116 -0,01040

eta0 0,26652 -0,05651 0,03846 -0,01341 0,00658

Phi 0,7874344 0,7874303 0,7874331 0,7874321 0,7874326

Lambda 0,3716279 0,3716370 0,3716307 0,3716328 0,3716318

DPhi["] 3,998 -0,848 0,577 -0,201 0,099

DLambda["] -9,238 1,882 -1,315 0,450 -0,221

A 0,23148 0,23162 0,23156 0,23157 0,23157

B -0,04566 -0,04545 -0,04577 -0,04563 -0,04570

C -73,05891 -72,66272 -72,73164 -72,68102 -72,69794

D -0,04266 -0,04270 -0,04267 -0,04268 -0,04267

E -0,21906 -0,21932 -0,21912 -0,21919 -0,21916

F 46,75433 46,51308 46,55888 46,52518 46,53720

K -0,00007 -0,00007 -0,00007 -0,00007 -0,00007

L -0,00046 -0,00046 -0,00046 -0,00046 -0,00046

s0 1,10100 1,10448 1,10355 1,10380 1,10378

F 1,21 1,22 1,22 1,22 1,22

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Conclusion

• Portability

• Field session: 30 - 60 min

• GPS: Good reliability of time-keeping

• CCD + GPS => elimination of observer’s error

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Thanks!