The ADOP and PDOP: Two complementary diagnostics for GNSS positioning

The Ambiguity Dilution of Precision (ADOP) and the Position Dilution of Precision (PDOP) are two popular scalar-diagnostics used in Global Navigation Satellite System (GNSS) positioning. Where the ADOP is a predictor for carrier-phase ambiguity resolution performance, the PDOP is meant to predict th...

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Main Authors: Wang, Kan, Teunissen, Peter, El-Mowafy, Ahmed
Format: Journal Article
Published: ASCE 2020
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/76754
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author Wang, Kan
Teunissen, Peter
El-Mowafy, Ahmed
author_facet Wang, Kan
Teunissen, Peter
El-Mowafy, Ahmed
author_sort Wang, Kan
building Curtin Institutional Repository
collection Online Access
description The Ambiguity Dilution of Precision (ADOP) and the Position Dilution of Precision (PDOP) are two popular scalar-diagnostics used in Global Navigation Satellite System (GNSS) positioning. Where the ADOP is a predictor for carrier-phase ambiguity resolution performance, the PDOP is meant to predict the receiver-satellite geometry’s capability for precise positioning. We will show however, although the PDOP works well for code-based positioning, that one has to exercise great care in using the PDOP for real-time kinematic (RTK) positioning. We show that the ADOP and PDOP have distinct behaviors, an important consequence of which is that one can have time periods with small PDOPs, and thus seemingly good geometry for precise positioning, but at the same time large ADOPs, thus showing that successful ambiguity resolution and therefore precise positioning will not be possible. Also the reverse situation may occur, i.e. having large PDOPs with small ADOPs. In such a situation, the large PDOPs should not automatically lead to the conclusion of poor position performance, since the large gain that ambiguity resolution brings will often still make precise positioning possible. We will analyse and explain this complementary behavior of the PDOP and ADOP, and demonstrate this both analytically and empirically. For this analysis we use real Global Positioning System (GPS) single- and multi-frequency signals and GPS/Quasi-Zenith Satellite System (QZSS), GPS/Navigation with Indian Constellation (NAVIC) L5 signals of two baselines located in Perth, Australia.
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institution Curtin University Malaysia
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publishDate 2020
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spelling curtin-20.500.11937-767542020-07-27T05:44:55Z The ADOP and PDOP: Two complementary diagnostics for GNSS positioning Wang, Kan Teunissen, Peter El-Mowafy, Ahmed 0909 - Geomatic Engineering Position Dilution of Precision (PDOP), Ambiguity Dilution of Precision (ADOP), Ambiguity Success-Rate (ASR), Integer Ambiguity Resolution (IAR), Real-Time Kinematic (RTK), Instantaneous Positioning. Yes The Ambiguity Dilution of Precision (ADOP) and the Position Dilution of Precision (PDOP) are two popular scalar-diagnostics used in Global Navigation Satellite System (GNSS) positioning. Where the ADOP is a predictor for carrier-phase ambiguity resolution performance, the PDOP is meant to predict the receiver-satellite geometry’s capability for precise positioning. We will show however, although the PDOP works well for code-based positioning, that one has to exercise great care in using the PDOP for real-time kinematic (RTK) positioning. We show that the ADOP and PDOP have distinct behaviors, an important consequence of which is that one can have time periods with small PDOPs, and thus seemingly good geometry for precise positioning, but at the same time large ADOPs, thus showing that successful ambiguity resolution and therefore precise positioning will not be possible. Also the reverse situation may occur, i.e. having large PDOPs with small ADOPs. In such a situation, the large PDOPs should not automatically lead to the conclusion of poor position performance, since the large gain that ambiguity resolution brings will often still make precise positioning possible. We will analyse and explain this complementary behavior of the PDOP and ADOP, and demonstrate this both analytically and empirically. For this analysis we use real Global Positioning System (GPS) single- and multi-frequency signals and GPS/Quasi-Zenith Satellite System (QZSS), GPS/Navigation with Indian Constellation (NAVIC) L5 signals of two baselines located in Perth, Australia. 2020 Journal Article http://hdl.handle.net/20.500.11937/76754 10.1061/(ASCE)SU.1943-5428.0000313 ASCE fulltext
spellingShingle 0909 - Geomatic Engineering
Position Dilution of Precision (PDOP), Ambiguity Dilution of Precision (ADOP), Ambiguity Success-Rate (ASR), Integer Ambiguity Resolution (IAR), Real-Time Kinematic (RTK), Instantaneous Positioning.
Yes
Wang, Kan
Teunissen, Peter
El-Mowafy, Ahmed
The ADOP and PDOP: Two complementary diagnostics for GNSS positioning
title The ADOP and PDOP: Two complementary diagnostics for GNSS positioning
title_full The ADOP and PDOP: Two complementary diagnostics for GNSS positioning
title_fullStr The ADOP and PDOP: Two complementary diagnostics for GNSS positioning
title_full_unstemmed The ADOP and PDOP: Two complementary diagnostics for GNSS positioning
title_short The ADOP and PDOP: Two complementary diagnostics for GNSS positioning
title_sort adop and pdop: two complementary diagnostics for gnss positioning
topic 0909 - Geomatic Engineering
Position Dilution of Precision (PDOP), Ambiguity Dilution of Precision (ADOP), Ambiguity Success-Rate (ASR), Integer Ambiguity Resolution (IAR), Real-Time Kinematic (RTK), Instantaneous Positioning.
Yes
url http://hdl.handle.net/20.500.11937/76754