Manual Title:
LD7 Operations Manual
Ref.:
AB-V-MA-00555
Rev No:
A9
Page 43
“It is essential to assess the precision and reliability of each position in order to ensure the
quality of the DGPS measurements. Thus is recommends that the following processing steps
be implemented: -
w-test for outliers carried out for each position fix
F-test for unit variance carried out for each position fix
When no more outliers are identified in any fix, precision and reliability measures will
be calculated:
o
Precision:
a-posteriori error ellipse
o
Reliability:
external reliability (positional MDE using a power of test of
80%)”
Where accuracy and precision statistical parameters are generated these all represent a 95% (2
σ)
confidence region.
Appendix A of the UKOOA guidelines emphasises this
by listing ‘Suggested parameters to be
specified by a system user for typical marine survey operations’ and states that ‘In order to carry out
rigorous QC, the covariance matrix generated by the least squares computation should be used to
generate test statistics and quality measures’.
It recommends the following Test Statistics:
1. w-test
used to detect outliers
2. F-test
used to verify the model which is being used to account for ‘errors’ in
the DGPS observations
It recommends also the following Quality Measures:
1. Error Ellipse
an approximate graphical representation of the positional standard
deviation in two dimensions
2. External Reliability
the effect of the maximum MDE (Marginally Detectable Error) on the
computed position
These recommendations are particularly aimed at survey applications but could be applied equally to
DP applications.
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Страница 1: ...Date 26 01 2017 LD7 Operations Manual Veripos ...
Страница 32: ...Manual Title LD7 Operations Manual Ref AB V MA 00555 Rev No A9 Page 32 APPENDIX I CONTACT INFORMATION ...
Страница 34: ...Manual Title LD7 Operations Manual Ref AB V MA 00555 Rev No A9 Page 34 APPENDIX II ABBREVIATIONS ...
Страница 36: ...Manual Title LD7 Operations Manual Ref AB V MA 00555 Rev No A9 Page 36 APPENDIX III VERIPOS REFERENCE STATIONS ...
Страница 41: ...Manual Title LD7 Operations Manual Ref AB V MA 00555 Rev No A9 Page 41 APPENDIX IV QUALITY STANDARDS ...
Страница 45: ...Manual Title LD7 Operations Manual Ref AB V MA 00555 Rev No A9 Page 45 APPENDIX V NMEA SENTENCES ...
Страница 55: ...Manual Title LD7 Operations Manual Ref AB V MA 00555 Rev No A9 Page 55 APPENDIX VI GLOBAL COVERAGE CHART ...
Страница 57: ...Manual Title LD7 Operations Manual Ref AB V MA 00555 Rev No A9 Page 57 APPENDIX VII HEADING ANTENNA GUIDE ...
