Bio

I am the director of the wide-area differential Global Navigation Satellite System(GNSS) laboratory at Stanford University. My work focuses on implementing high-integrity air navigation systems. I am also active in the international standards bodies coordinating the use of GNSS to implement these systems.

Academic Appointments

Honors & Awards

  • Leadership Award in Signal Design, GPS World Magazine (September, 2015)
  • Distinguished Service Award, Institute of Navigation (January, 2012)
  • Kepler Award, Institute of Navigation (September, 2010)
  • Thurlow Award, Institute of Navigation (January, 2008)
  • Fellow of the ION, Institute of Navigation (June, 2006)
  • Early Achievement Award, Institute of Navigation (June, 2000)

Boards, Advisory Committees, Professional Organizations

  • Member, National Space-Based Positioning, Navigation, and Timing Advisory Board (2019 - Present)
  • Member, IEEE (2014 - Present)
  • President, Institute of Navigation (2010 - 2012)
  • Member, Institute of Navigation (1994 - Present)

Professional Education

  • Ph.D., Stanford University, Applied Physics (1994)
  • M.S., Stanford University, Applied Physics (1990)
  • B.S., Rensselaer Polytechnic Institute, Physics (1987)

Contact

  • Academic
    twalter@stanford.edu
    University - Faculty Department: Aeronautics and Astronautics Position: Professor-Research
    • 496 Lomita Mall / Room 459
    • Stanford,  California  94305-4035 
    (650) 725-5517 (fax)

Additional Info

Links

Current Research and Scholarly Interests

High integrity satellite navigation for guiding aircraft, including satellite based augmentation systems (SBAS) and advanced receiver autonomous integrity monitoring (ARAIM).

2024-25 Courses

Stanford Advisees

All Publications

  • Determination of Fault Probabilities for ARAIM IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Walter, T., Blanch, J., Gunning, K., Joerger, M., Pervan, B. 2019; 55 (6): 3505–16

    View details for DOI 10.1109/TAES.2019.2909727

    View details for Web of Science ID 000507917800066

  • An Overview of Advanced Receiver Autonomous Integrity Monitoring (ARAIM) Walter, T., Inst Navigat INST NAVIGATION. 2019: 896–914

    View details for DOI 10.33012/2019.16848

    View details for Web of Science ID 000475697600075

  • Quantum-resistant authentication algorithms for satellite-based augmentation systems NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Neish, A., Walter, T., Enge, P. 2019; 66 (1): 199–209

    View details for DOI 10.1002/navi.287

    View details for Web of Science ID 000462203300016

  • Broadband LEO Constellations for Navigation NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Reid, T. R., Neish, A. M., Walter, T., Enge, P. K. 2018; 65 (2): 205–20

    View details for DOI 10.1002/navi.234

    View details for Web of Science ID 000439832100005

  • Worldwide Vertical Guidance of Aircraft Based on Modernized GPS and New Integrity Augmentations PROCEEDINGS OF THE IEEE Walter, T., Enge, P., Blanch, J., Pervan, B. 2008; 96 (12): 1918-1935

    View details for DOI 10.1109/JPROC.2008.2006099

    View details for Web of Science ID 000262934800004

  • Robust Detection of Ionospheric Irregularities NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Walter, T., et al 2001; 48 (2): 89–100

    View details for DOI 10.1002/j.2161-4296.2001.tb00231.x

  • Wide area augmentation of the global positioning system PROCEEDINGS OF THE IEEE Enge, P., Walter, T., Pullen, S., Kee, C., Chao, Y. C., Tsai, Y. J. 1996; 84 (8): 1063-1088

    View details for Web of Science ID A1996UY25000002

  • Weighted RAIM for precision approach 8th International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GPS-95) Walter, T., Enge, P. INST NAVIGATION. 1995: 1995–2004

    View details for Web of Science ID A1995BE72A00215

  • Authentication Security of Combinatorial Watermarking for GNSS Signal Authentication NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Anderson, J., Lo, S., Walter, T. 2024; 71 (3)

    View details for DOI 10.33012/navi.655

    View details for Web of Science ID 001265046100002

  • Software Defined Radio for GNSS Radio Frequency Interference Localization. Sensors (Basel, Switzerland) Taylor, F., Gattis, E., Trapani, L., Akos, D., Lo, S., Walter, T., Chen, Y. 2023; 24 (1)

    Abstract

    The use of radio direction finding techniques in order to identify and reject harmful interference has been a topic of discussion both past and present for signals in the GNSS bands. Advances in commercial off-the-shelf radio hardware have led to the development of new low-cost, compact, phase coherent receiver platforms such as the KrakenSDR from KrakenRF whose testing and characterization will be the primary focus of this paper. Although not specifically designed for GNSSs, the capabilities of this platform are well aligned with the needs of GNSSs. Testing results from both benchtop and in the field will be displayed which verify the KrakenSDR's phase coherence and angle of arrival estimates to array dependent resolution bounds. Additionally, other outputs from the KrakenSDR such as received signal strength indicators and the angle of arrival confidence values show strong connections to angle of arrival estimate quality. Within this work the testing that will be primarily presented is at 900 MHz, with results presented from a government-sponsored event where the Kraken was tested at 1575.42 MHz. Finally, a discussion of calibration of active antenna arrays for angle of arrival is included as the introduction of active antenna elements used in GNSS signal collection can influence angle of arrival estimation.

    View details for DOI 10.3390/s24010072

    View details for PubMedID 38202934

  • Calibration of RFI Detection Levels in a Low-Cost GNSS Monitor Miguel, N., Chen, Y., Lo, S., Walter, T., Akos, D., IEEE IEEE. 2023: 520-535

    View details for DOI 10.1109/PLANS53410.2023.10140085

    View details for Web of Science ID 001022344800061

  • An Evaluation of the Advanced RAIM Threat Model Blanch, J., Walter, T., IEEE IEEE. 2023: 408-413

    View details for DOI 10.1109/PLANS53410.2023.10139928

    View details for Web of Science ID 001022344800049

  • WAAS and the Ionosphere - A Historical Perspective: Monitoring Storms NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Sparks, L., Altshuler, E., Pandya, N., Blanch, J., Walter, T. 2022; 69 (1)

    View details for DOI 10.33012/navi.503

    View details for Web of Science ID 000790870400004

  • Authentication of Satellite-Based Augmentation Systems with Over-the-Air Rekeying Schemes NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Anderson, J., Lo, S., Neish, A., Walter, T. 2022; 70 (3)

    View details for DOI 10.33012/navi.595

    View details for Web of Science ID 001046442800006

  • A Framework for GNSS Spoofing Detection Through Combinations of Metrics IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Rothmaier, F., Chen, Y., Lo, S., Walter, T. 2021; 57 (6): 3633-3647

    View details for DOI 10.1109/TAES.2021.3082673

    View details for Web of Science ID 000725819700010

  • GNSS spoofing detection through spatial processing NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Rothmaier, F., Chen, Y., Lo, S., Walter, T. 2021

    View details for DOI 10.1002/navi.420

    View details for Web of Science ID 000647529400001

  • Performance of 6 Different Global Navigation Satellite System Receivers at Low Latitude Under Moderate and Strong Scintillation EARTH AND SPACE SCIENCE de Paula, E. R., Martinon, A. F., Moraes, A. O., Carrano, C., Neto, A. C., Doherty, P., Groves, K., Valladares, C. E., Crowley, G., Azeem, Reynolds, A., Akos, D. M., Walter, T., Beach, T. L., Slewaegen, J. 2021; 8 (2)

    View details for DOI 10.1029/2020EA001314

    View details for Web of Science ID 000624393800005

  • Fast Protection Levels for Fault Detection With an Application to Advanced RAIM IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Blanch, J., Walter, T. 2021; 57 (1): 55–65

    View details for DOI 10.1109/TAES.2020.3011997

    View details for Web of Science ID 000617426500005

  • GNSS Spoofing Mitigation in the Position Domain Rothmaier, F., Chen, Y., Lo, S., Walter, T., Inst Navigat INST NAVIGATION. 2021: 42-55

    View details for DOI 10.33012/2021.17824

    View details for Web of Science ID 000671019900005

  • Ionospheric Scintillation Effects on Satellite Navigation IONOSPHERE DYNAMICS AND APPLICATIONS Datta-Barua, S., Altshuler, E., Walter, T., Pullen, S., Huang, C., Lu, G., Zhang, Y., Paxton, L. J. 2021; 260: 493-510

    View details for DOI 10.1002/9781119815617.ch20

    View details for Web of Science ID 000852623000021

  • Message Authentication Candidates for the SBAS Dual Frequency Multi-Constellation Standard Fernandez-Hernandez, I., Walter, T., Mabilleau, M., Tosato, L., Chiara, A., Pozza, D., Pozzobon, O., Calabrese, A., Anderson, J., Chatre, E., INST NAVIGAT INST NAVIGATION. 2021: 443-452

    View details for DOI 10.33012/2021.17892

    View details for Web of Science ID 000874785700023

  • Developing a Practical GNSS Spoofing Detection Thresholds for Receiver Power Monitoring Lo, S., Rothmaier, F., Miralles, D., Akos, D., Walter, T., INST NAVIGAT INST NAVIGATION. 2021: 803-815

    View details for DOI 10.33012/2021.17931

    View details for Web of Science ID 000874785700044

  • A FAULT DETECTION AND EXCLUSION ESTIMATOR DESIGNED FOR INTEGRITY Blanch, J., Walter, T., INST NAVIGAT INST NAVIGATION. 2021: 1672-1686

    View details for DOI 10.33012/2021.17954

    View details for Web of Science ID 000874785701044

  • GNSS Interference Detection Using Machine Learning Algorithms on ADS-B Data Liu, Z., Lo, S., Walter, T., INST NAVIGAT INST NAVIGATION. 2021: 4305-4315

    View details for DOI 10.33012/2021.18111

    View details for Web of Science ID 000874785704028

  • Analysis of GNSS Constellation Performance for Advanced RAIM Blanch, J., Liu, X., Gunning, K., Walter, T., INST NAVIGAT INST NAVIGATION. 2021: 1410-1434

    View details for DOI 10.33012/2021.18148

    View details for Web of Science ID 000874785701029

  • SBAS Message Schemes to Support Inline Message Authentication Walter, T., Anderson, J., Lo, S., INST NAVIGAT INST NAVIGATION. 2021: 474-484

    View details for DOI 10.33012/2021.17908

    View details for Web of Science ID 000874785700025

  • Ground Monitoring to Support ARAIM for Military Users: Alternatives for Rapid and Rare Update Rates Pullen, S., Lo, S., Katz, A., Blanch, J., Walter, T., Katronick, A., Crews, M., Johnson, R., INST NAVIGAT INST NAVIGATION. 2021: 1481-1507

    View details for DOI 10.33012/2021.18159

    View details for Web of Science ID 000874785701033

  • GNSS Spoofing Detection through Metric Combinations: Calibration and Application of a general Framework Rothmaier, F., Taleghani, L., Chen, Y., Lo, S., Phelts, E., Walter, T., INST NAVIGAT INST NAVIGATION. 2021: 4249-4263

    View details for DOI 10.33012/2021.18126

    View details for Web of Science ID 000874785704024

  • Providing Continuity and Integrity in the Presence of GNSS Spoofing Rothmaier, F., Chen, Y., Lo, S., Blanch, J., Walter, T., INST NAVIGAT INST NAVIGATION. 2021: 1828-1842

    View details for DOI 10.33012/2021.17984

    View details for Web of Science ID 000874785701053

  • Adopting Neural Networks in GNSS-IMU integration: A Preliminary study Shin, Y., Lee, C., Kim, E., Walter, T., IEEE IEEE. 2021

    View details for DOI 10.1109/DASC52595.2021.9594430

    View details for Web of Science ID 000739652600131

  • Reevaluating the Message Loss Rate of the Wide Area Augmentation System (WAAS) in Flight Hirschberger, M. J., Lo, S., Walter, T., Inst Navigat INST NAVIGATION. 2021: 218-228

    View details for DOI 10.33012/2021.17819

    View details for Web of Science ID 000671019900018

  • SBAS message authentication: a review of protocols, figures of merit and standardization plans Fernandez-Hernandez, I., Walter, T., Neish, A. M., Anderson, J., Mabilleau, M., Vecchione, G., Chatre, E., Inst Navigat INST NAVIGATION. 2021: 111-124

    View details for DOI 10.33012/2021.17829

    View details for Web of Science ID 000671019900010

  • Investigation into September 2020 GPS SVN 74 Performance Anomaly Walter, T., Liu, Z., Blanch, J., Pham, K., Mick, J., Wanner, W., Inst Navigat INST NAVIGATION. 2021: 189-200

    View details for DOI 10.33012/2021.17818

    View details for Web of Science ID 000671019900015

  • Assessment of Ionospheric Correction Behavior for Use with Precise Point Positioning (PPP) Walter, T., Blanch, J., de Groot, L., Norman, L., Inst Navigat INST NAVIGATION. 2021: 616-624

    View details for DOI 10.33012/2021.17853

    View details for Web of Science ID 000671019900048

  • ARAIM for Military Users: ISM Parameters, Constellation-Check Procedure and Performance Estimates Katz, A., Pullen, S., Lo, S., Blanch, J., Walter, T., Katronick, A., Crews, M., Jackson, R., Inst Navigat INST NAVIGATION. 2021: 173-188

    View details for DOI 10.33012/2021.17812

    View details for Web of Science ID 000671019900014

  • GAUSSIAN BOUNDING IMPROVEMENTS AND AN ANALYSIS OF THE BIAS-SIGMA TRADEOFF FOR GNSS INTEGRITY Blanch, J., Liu, X., Walter, T., Inst Navigat INST NAVIGATION. 2021: 703-713

    View details for DOI 10.33012/2021.17861

    View details for Web of Science ID 000671019900056

  • An Assessment of GPS Spoofing Detection Via Radio Power and Signal Quality Monitoring for Aviation Safety Operations IEEE INTELLIGENT TRANSPORTATION SYSTEMS MAGAZINE Miralles, D., Levigne, N., Bornot, A., Rouquette, P., Akos, D. M., Chen, Y., La, S., Walter, T. 2020; 12 (3): 136–46

    View details for DOI 10.1109/MITS.2020.2994117

    View details for Web of Science ID 000552261600009

  • Receiver States for SBAS Data Authentication Neish, A., Walter, T., Fernandez-Hernandez, I., Inst Navigat INST NAVIGATION. 2020: 1059–69

    View details for DOI 10.33012/2020.17197

    View details for Web of Science ID 000544820300074

  • BOUNDING TEMPORALLY CORRELATED MEASUREMENT NOISE WITH AN APPLICATION TO GNSS INTEGRITY Blanch, J., Phelts, E., Gunning, K., Walter, T., de Groot, L., Norman, L., Inst Navigat INST NAVIGATION. 2020: 27-38

    View details for DOI 10.33012/2020.17549

    View details for Web of Science ID 000632603500002

  • Characterization of ADS-B Performance under GNSS Interference Liu, Z., Lo, S., Walter, T., Inst Navigat INST NAVIGATION. 2020: 3581-3591

    View details for DOI 10.33012/2020.17675

    View details for Web of Science ID 000632603503044

  • Independent Time Synchronization for Resilient GNSS Receivers Fernandez-Hernandez, I., Walter, T., Neish, A., O'Driscoll, C., Inst Navigat INST NAVIGATION. 2020: 964–78

    View details for DOI 10.33012/2020.17190

    View details for Web of Science ID 000544820300067

  • Stress Testing Advanced RAIM Airborne Algorithms Blanch, J., Walter, T., Inst Navigat INST NAVIGATION. 2020: 421–39

    View details for DOI 10.33012/2020.17153

    View details for Web of Science ID 000544820300026

  • Evaluating the Application of PPP Techniques to ARAIM Using Flight Data Phelts, R., Gunning, K., Blanch, J., Walter, T., Inst Navigat INST NAVIGATION. 2020: 379–85

    View details for DOI 10.33012/2020.17151

    View details for Web of Science ID 000544820300023

  • Design and analysis of a public key infrastructure for SBAS data authentication NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Neish, A., Walter, T., Powell, J. D. 2019; 66 (4): 831–44

    View details for DOI 10.1002/navi.338

    View details for Web of Science ID 000507100800010

  • Gaussian Bounds of Sample Distributions for Integrity Analysis IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Blanch, J., Walter, T., Enge, P. 2019; 55 (4): 1806–15

    View details for DOI 10.1109/TAES.2018.2876583

    View details for Web of Science ID 000480348800017

  • Signal Deformation Monitoring for Anomalous Multipath Threats Phelts, R., Walter, T., Inst Navigat INST NAVIGATION. 2019: 1023–30

    View details for DOI 10.33012/2019.16853

    View details for Web of Science ID 000475697600084

  • Development of Advanced RAIM Minimum Operational Performance Standards Blanch, J., Walter, T., Berz, G., Burns, J., Clark, B., Joerger, M., Mabilleau, M., Martini, I., Milner, C., Pervan, B., Lee, Y., Inst Navigat INST NAVIGATION. 2019: 1381–91

    View details for DOI 10.33012/2019.16904

    View details for Web of Science ID 000568618901029

  • SBAS Data Authentication: A Concept of Operations Neish, A., Walter, T., Powell, J., Inst Navigat INST NAVIGATION. 2019: 1812–23

    View details for DOI 10.33012/2019.17086

    View details for Web of Science ID 000568618901056

  • Integrity for Tightly Coupled PPP and IMU Gunning, K., Blanch, J., Walter, T., de Groot, L., Norman, L., Inst Navigat INST NAVIGATION. 2019: 3066–78

    View details for DOI 10.33012/2019.17011

    View details for Web of Science ID 000568618903010

  • Going Back for the Future: Large/Mega LEO Constellations for Navigation Reid, T., Gunning, K., Perkins, A., Lo, S., Walter, T., Inst Navigat INST NAVIGATION. 2019: 2452–68

    View details for DOI 10.33012/2019.17123

    View details for Web of Science ID 000568618902065

  • Increasing International Civil Aviation Resilience: A Proposal for Nomenclature, Categorization and Treatment of New Interference Threats Fernandez-Hernandez, I., Walter, T., Alexander, K., Clark, B., Chatre, E., Hegarty, C., Appel, M., Meurer, M., Inst Navigat INST NAVIGATION. 2019: 389–407

    View details for DOI 10.33012/2019.16699

    View details for Web of Science ID 000542920400028

  • SBAS Corrections for PPP Integrity with Solution Separation Gunning, K., Blanch, J., Walter, T., Inst Navigat INST NAVIGATION. 2019: 707–19

    View details for DOI 10.33012/2019.16739

    View details for Web of Science ID 000542920400055

  • Development and Evaluation of Airborne Multipath Error Bounds for L1-L5 Blanch, J., Walter, T., Phelts, R., Inst Navigat INST NAVIGATION. 2019: 53–61

    View details for DOI 10.33012/2019.16735

    View details for Web of Science ID 000542920400003

  • Reducing Computational Load in Solution Separation for Kalman Filters and an Application to PPP Integrity Blanch, J., Gunning, K., Walter, T., De Groot, L., Norman, L., Inst Navigat INST NAVIGATION. 2019: 720–29

    View details for DOI 10.33012/2019.16721

    View details for Web of Science ID 000542920400056

  • Safety Analysis of Ranging Biases on the WAAS GEOs Walter, T., Blanch, J., Altshuler, E., Inst Navigat INST NAVIGATION. 2019: 113–30

    View details for DOI 10.33012/2019.16679

    View details for Web of Science ID 000542920400008

  • Paper Trends in ION Conferences from 2007-2018 Perkins, A., Walter, T., Inst Navigat INST NAVIGATION. 2019: 340–48

    View details for DOI 10.33012/2019.16790

    View details for Web of Science ID 000475697600025

  • Design and Analysis of a Public Key Infrastructure for SBAS Data Authentication Neish, A., Walter, T., Powell, J., Inst Navigat INST NAVIGATION. 2019: 964–88

    View details for DOI 10.33012/2019.16852

    View details for Web of Science ID 000475697600080

  • Lower Bounds in Optimal Integrity Monitoring Blanch, J., Walter, T., Inst Navigat INST NAVIGATION. 2019: 915–24

    View details for DOI 10.33012/2019.16788

    View details for Web of Science ID 000475697600076

  • SIS Monitoring for ARAIM in the Absence of Precise Clock Estimates Gunning, K., Walter, T., Powell, D., Inst Navigat INST NAVIGATION. 2019: 785–801

    View details for DOI 10.33012/2019.16838

    View details for Web of Science ID 000475697600065

  • Standards for ARAIM ISM Data Analysis Walter, T., Blanch, J., Gunning, K., Inst Navigat INST NAVIGATION. 2019: 777–84

    View details for DOI 10.33012/2019.16837

    View details for Web of Science ID 000475697600064

  • WAAS at 15 NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Walter, T., Shallberg, K., Altshuler, E., Wanner, W., Harris, C., Stimmler, R. 2018; 65 (4): 581–600

    View details for DOI 10.1002/navi.252

    View details for Web of Science ID 000454313700007

  • Validation of the Unfaulted Error Bounds for ARAIM NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Walter, T., Gunning, K., Phelts, R., Blanch, J. 2018; 65 (1): 117–33

    View details for Web of Science ID 000428524500010

  • A Formula for Solution Separation without Subset Solutions for Advanced RAIM Blanch, J., Walter, T., Enge, P., IEEE IEEE. 2018: 316–26

    View details for Web of Science ID 000435257800042

  • Spoofing Detection for Airborne GNSS Equipment Hegarty, C., Odeh, A., Shallberg, K., Wesson, K., Walter, T., Alexander, K., Inst Navigat INST NAVIGATION. 2018: 1350–68

    View details for DOI 10.33012/2018.16008

    View details for Web of Science ID 000545000101024

  • Design and evaluation of integrity algorithms for PPP in kinematic applications Gunning, K., Blanch, J., Walter, T., de Groot, L., Norman, L., Inst Navigat INST NAVIGATION. 2018: 1910–39

    View details for DOI 10.33012/2018.15972

    View details for Web of Science ID 000545000101065

  • A Proposed Concept of Operations for Advanced Receiver Autonomous Integrity Monitoring Blanch, J., Walter, T., Enge, P., Burns, J., Mabilleau, M., Martini, I., Boyero, J., Berz, G., Inst Navigat INST NAVIGATION. 2018: 1084–90

    View details for DOI 10.33012/2018.15934

    View details for Web of Science ID 000545000101007

  • Parameter Selection for the TESLA Keychain Neish, A., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2018: 2155–71

    View details for DOI 10.33012/2018.15852

    View details for Web of Science ID 000545000102014

  • Effect of Aircraft Banking on ARAIM Performance Phelts, R., Blanch, J., Gunning, K., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2018: 2632–41

    View details for DOI 10.33012/2018.16027

    View details for Web of Science ID 000545000102046

  • GNSS Multipath Error Modeling for Automotive Applications Khanafseh, S., Kujur, B., Joerger, M., Walter, T., Pullen, S., Blanch, J., Doherty, K., Norman, L., de Groot, L., Pervan, B., Inst Navigat INST NAVIGATION. 2018: 1573–89

    View details for DOI 10.33012/2018.16107

    View details for Web of Science ID 000545000101039

  • Ionospheric Rates of Change Walter, T., Blanch, J., de Groot, L., Norman, L., Joerger, M., Inst Navigat INST NAVIGATION. 2018: 4158–70

    View details for DOI 10.33012/2018.16112

    View details for Web of Science ID 000545000104021

  • Fixed Subset Selection to Reduce Advanced RAIM Complexity Blanch, J., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2018: 88–98

    View details for Web of Science ID 000436563900008

  • GNSS Multipath Detection in Urban Environment Using 3D Building Model Zhang, S., Lo, S., Chen, Y., Walter, T., Enge, P., IEEE IEEE. 2018: 1053–58

    View details for Web of Science ID 000435257800131

  • WASS at 15 Walter, T., Shallberg, K., Altshuler, E., Wanner, W., Harris, C., Stimmler, R., Inst Navigat INST NAVIGATION. 2018: 301–21

    View details for Web of Science ID 000436563900026

  • Quantum Resistant Authentication Algorithms for Satellite-Based Augmentation Systems Neish, A., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2018: 365–79

    View details for Web of Science ID 000436563900030

  • Effective GPS Spoofing Detection Utilizing Metrics from Commercial Receivers Manfredini, E., Akos, D. M., Chen, Y., Lo, S., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2018: 672–89

    View details for Web of Science ID 000436563900052

  • Protection Levels after Fault Exclusion for Advanced RAIM NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Blanch, J., Walter, T., Enge, P. 2017; 64 (4): 505–13

    View details for DOI 10.1002/navi.210

    View details for Web of Science ID 000418762800007

  • Improved User Position Monitor for WAAS NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Walter, T., Blanch, J. 2017; 64 (1): 165–75

    View details for DOI 10.1002/navi.180

    View details for Web of Science ID 000403758600012

  • Theoretical Results on the Optimal Detection Statistics for Autonomous Integrity Monitoring NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Blanch, J., Walter, T., Enge, P. 2017; 64 (1): 123–37

    View details for DOI 10.1002/navi.175

    View details for Web of Science ID 000403758600009

  • Multi-GNSS Constellation Anomaly Detection and Performance Monitoring Gunning, K., Walter, T., Enge, P., INST NAVIGAT INST NAVIGATION. 2017: 1051–62

    View details for Web of Science ID 000419292301006

  • Characterization of GLONASS Broadcast Clock and Ephemeris: Nominal Performance and Fault Trends for ARAIM Gunning, K., Walter, T., Enge, P., INST NAVIGAT INST NAVIGATION. 2017: 170–83

    View details for Web of Science ID 000405076700013

  • Catalog and Description of GPS and WAAS L1 C/A Signal Deformation Events Shallberg, K. W., Ericson, S. D., Phelts, E., Walter, T., Kovach, K., Altshuler, E., INST NAVIGAT INST NAVIGATION. 2017: 508–20

    View details for Web of Science ID 000405076700036

  • Validation of the Unfaulted Error Bounds for ARAIM Walter, T., Gunning, K., Phelts, R., Blanch, J., Inst Navigat INST NAVIGATION. 2017: 1–19

    View details for DOI 10.33012/2017.15047

    View details for Web of Science ID 000542915000001

  • The Benefit of Low Cost Accelerometers for GNSS Anti-Spoofing Lo, S., Chen, Y., Reid, T., Perkins, A., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2017: 775–96

    View details for DOI 10.33012/2017.15109

    View details for Web of Science ID 000542915000058

  • WAAS Signal Deformation Monitor Performance: Beyond the ICAO Threat Model Phelts, R., Shallberg, K., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2017: 713–24

    View details for DOI 10.33012/2017.15103

    View details for Web of Science ID 000542915000053

  • A MATLAB Toolset to Determine Strict Gaussian Bounding Distributions of a Sample Distribution Blanch, J., Walter, T., Enge, P., INST NAVIGAT INST NAVIGATION. 2017: 4236–47

    View details for Web of Science ID 000419292304023

  • Feasibility of fault exclusion related to advanced RAIM for GNSS spoofing detection Kuusniemi, H., Blanch, J., Chen, Y., Lo, S., Innac, A., Ferrara, G., Honkala, S., Bhuiyan, M. H., Thombre, S., Soderholm, S., Walter, T., Phelts, R., Enge, P., INST NAVIGAT INST NAVIGATION. 2017: 2359–70

    View details for Web of Science ID 000419292302029

  • Orbital representations for the next generation of satellite-based augmentation systems GPS SOLUTIONS Reid, T. G., Walter, T., Enge, P. K., Sakai, T. 2016; 20 (4): 737-750

    View details for DOI 10.1007/s10291-015-0485-x

    View details for Web of Science ID 000384421600013

  • Preliminary availability assessment to support single-frequency SBAS development in the Korean region GPS SOLUTIONS Bang, E., Lee, J., Walter, T., Lee, J. 2016; 20 (3): 299-312

    View details for DOI 10.1007/s10291-016-0522-4

    View details for Web of Science ID 000378539400001

  • Leveraging Commercial Broadband LEO Constellations for Navigation Reid, T. R., Neish, A. M., Walter, T. F., Enge, P. K., Inst Navigat INST NAVIGATION. 2016: 2300–2314

    View details for Web of Science ID 000391479502030

  • Improved Ephemeris Monitoring for GNSS Walter, T., Gunning, K., Blanch, J., Inst Navigat INST NAVIGATION. 2016: 600–608

    View details for Web of Science ID 000379864100059

  • Determination of Fault Probabilities for ARAIM Walter, T., Blanch, J., Joerger, M., Pervan, B., IEEE IEEE. 2016: 451–61

    View details for Web of Science ID 000389021800060

  • Improved User Position Monitor for WAAS Walter, T., Blanch, J., Inst Navigat INST NAVIGATION. 2016: 343–52

    View details for Web of Science ID 000379864100030

  • Mitigation of short duration satellite outages for Advanced RAIM and other integrity systems based on GNSS Blanch, J., Chen, Y., Phelts, R., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2016: 1688–95

    View details for Web of Science ID 000391479501067

  • A Simple Satellite Exclusion Algorithm for Advanced RAIM Blanch, J., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2016: 239–44

    View details for Web of Science ID 000379864100020

  • Demonstrating ARAIM on UAS using Software Defined Radio and Civilian Signal GPS L1/L2C and GLONASS G1/G2 Chen, Y., Perkins, A., Lo, S., Akos, D. M., Blanch, J., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2016: 231–38

    View details for Web of Science ID 000379864100019

  • Satellite Selection for Multi-Constellation SBAS Walter, T., Blanch, J., Kropp, V., Inst Navigat INST NAVIGATION. 2016: 1350–59

    View details for Web of Science ID 000391479501038

  • GNSS Integrity in The Arctic NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Reid, T., Walter, T., Blanch, J., Enge, P. 2016; 63 (4): 469-492

    View details for Web of Science ID 000397681800008

  • A Simple Position Estimator That Improves Advanced RAIM Performance IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Blanch, J., Walter, T., Enge, P., Kropp, V. 2015; 51 (3): 2485-U960

    View details for DOI 10.1109/TAES.2015.140674

    View details for Web of Science ID 000362015800070

  • GNSS Multipath and Jamming Mitigation Using High-Mask-Angle Antennas and Multiple Constellations IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS Heng, L., Walter, T., Enge, P., Gao, G. X. 2015; 16 (2): 741-750

    View details for DOI 10.1109/TITS.2014.2342200

    View details for Web of Science ID 000352282500018

  • Aviation Benefits from Satellite Navigation NEW SPACE Enge, P., Enge, N., Walter, T., Eldredge, L. 2015; 3 (1): 19–35

    View details for DOI 10.1089/space.2014.0011

    View details for Web of Science ID 000355562700004

  • Baseline Advanced RAIM User Algorithm and Possible Improvements IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Blanch, J., Walker, T., Enge, P., Lee, Y., Pervan, B., Rippl, M., Spletter, A., Kropp, V. 2015; 51 (1): 713-732

    View details for DOI 10.1109/TAES.2014.130739

    View details for Web of Science ID 000352700900055

  • GNSS Integrity in The Arctic Reid, T. R., Walter, T., Blanch, J., Enge, P. K., Inst Navigat INST NAVIGATION. 2015: 1726–40

    View details for Web of Science ID 000375211601050

  • Progress on Working Group-C Activities on Advanced RAIM Blanch, J., Walter, T., Enge, P., Burns, J., Alexander, K., Boyero, J., Lee, Y., Pervan, B., Joerger, M., Khanafseh, S., Rippl, M., Martini, I., Perea, S., Kropp, V., Macabiau, C., Suard, N., Berz, G., Inst Navigat INST NAVIGATION. 2015: 629–38

    View details for Web of Science ID 000375211600044

  • Validating Nominal Bias Error Limits Using 4 years of WAAS Signal Quality Monitoring Data Phelts, R., Altshuler, E., Walter, T., Inst Navigat INST NAVIGATION. 2015: 956–63

    View details for Web of Science ID 000365398300083

  • GPS Multi-Frequency Carrier Phase Characterization During Strong Equatorial Ionospheric Scintillation Xu, D., Morton, Y., Akos, D., Walter, T., Inst Navigat INST NAVIGATION. 2015: 3787–96

    View details for Web of Science ID 000375211603086

  • A Comparative Study of Triple Frequency GPS Scintillation Signal Amplitude Fading Characteristics at Low Latitudes Jiao, Y., Morton, Y., Akos, D., Walter, T., Inst Navigat INST NAVIGATION. 2015: 3819–25

    View details for Web of Science ID 000375211603089

  • Fast Multiple Fault Exclusion with a Large Number of Measurements Blanch, J., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2015: 696–701

    View details for Web of Science ID 000365040300074

  • Characterization of GPS Clock and Ephemeris Errors to Support ARAIM Walter, T., Blanch, J., Inst Navigat INST NAVIGATION. 2015: 920–31

    View details for Web of Science ID 000365398300080

  • Airborne Mitigation Of Constellation Wide Faults Walter, T., Blanch, J., Inst Navigat INST NAVIGATION. 2015: 676–86

    View details for Web of Science ID 000365040300072

  • Future Dual-Frequency GPS Navigation System for Intelligent Air Transportation Under Strong Ionospheric Scintillation IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS Seo, J., Walter, T. 2014; 15 (5): 2224-2236

    View details for DOI 10.1109/TITS.2014.2311590

    View details for Web of Science ID 000343002400032

  • The Effect of Nominal Signal Deformations on ARAIM Users International Technical Meeting of the Institute-of-Navigation Phelts, R. E., Blanch, J., Walter, T., Enge, P. INST NAVIGATION. 2014: 56–67

    View details for Web of Science ID 000339630900003

  • Architectures for Advanced RAIM: Offline and Online Blanch, J., Walter, T., Enge, P., Pervan, B., Joerger, M., Khanafseh, S., Burns, J., Alexander, K., Boyero, J., Lee, Y., Kropp, V., Milner, C., Macabiau, C., Suard, N., Berz, G., Rippl, M., Inst Navigat INST NAVIGATION. 2014: 787–804

    View details for Web of Science ID 000356331201004

  • Scintillation Characterization for WAAS in the Auroral Region Altshuler, E., Shallberg, K., Potter, B. J., Walter, T., Inst Navigat INST NAVIGATION. 2014: 1126–37

    View details for Web of Science ID 000356331201036

  • Single Antenna GPS Spoof Detection that is Simple, Static, Instantaneous and Backwards Compatible for Aerial Applications McMilin, E., De Lorenzo, D. S., Walter, T., Lee, T. H., Enge, P., Inst Navigat INST NAVIGATION. 2014: 2233–42

    View details for Web of Science ID 000356331203017

  • Mitigation of Nominal Signal Deformations on Dual-Frequency WAAS Position Errors Wong, G., Chen, Y., Phelts, R., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2014: 3129–47

    View details for Web of Science ID 000356331204023

  • VPL Parameter Determination for Improved Performance of Advanced RAIM Lee, J., Kim, D., Lee, J., Walter, T., Inst Navigat INST NAVIGATION. 2014: 3566–74

    View details for Web of Science ID 000356331205013

  • Experimentally Recorded Amplitude and Phase Scintillation through a Spirent Simulator Jayawardena, T., Ali, A. M., Forte, B., Kinrade, J., Mitchell, C., Smith, S., Walter, T., Inst Navigat INST NAVIGATION. 2014: 1108–14

    View details for Web of Science ID 000356331201034

  • Evaluation of a covariance-based clock and ephemeris error bounding algorithm for SBAS Blanch, J., Walter, T., Enge, P., Stern, A., Altshuler, E., Inst Navigat INST NAVIGATION. 2014: 3270–76

    View details for Web of Science ID 000356331204038

  • Exclusion for Advanced RAIM: Requirements and a Baseline Algorithm International Technical Meeting of the Institute-of-Navigation Blanch, J., Walter, T., Enge, P. INST NAVIGATION. 2014: 99–107

    View details for Web of Science ID 000339630900007

  • Effects of solar cycle 24 activity onWAAS navigation SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS Datta-Barua, S., Walter, T., Bust, G. S., Wanner, W. 2014; 12 (1): 46-63

    View details for DOI 10.1002/2013SW000982

    View details for Web of Science ID 000331551300006

  • Crowdsourcing Arctic Navigation Using Multispectral Ice Classification & GNSS PROCEEDINGS OF THE 27TH INTERNATIONAL TECHNICAL MEETING OF THE SATELLITE DIVISION OF THE INSTITUTE OF NAVIGATION (ION GNSS 2014) Reid, T., Walter, T., Enge, P., Fowler, A. 2014: 707-721

    View details for Web of Science ID 000356331201001

  • Reduced Subset Analysis for Multi-Constellation ARAIM International Technical Meeting of the Institute-of-Navigation Walter, T., Blanch, J., Enge, P. INST NAVIGATION. 2014: 89–98

    View details for Web of Science ID 000339630900006

  • Development of a Real-time GNSS Software Receiver for Evaluating RAIM in Multi-constellation International Technical Meeting of the Institute-of-Navigation Chen, Y., Lo, S., Akos, D. M., Choi, M., Blanch, J., Walter, T., Enge, P. INST NAVIGATION. 2014: 525–533

    View details for Web of Science ID 000339630900053

  • DME/TACAN interference mitigation for GNSS: algorithms and flight test results GPS SOLUTIONS Gao, G. X., Heng, L., Hornbostel, A., Denks, H., Meurer, M., Walter, T., Enge, P. 2013; 17 (4): 561-573

    View details for DOI 10.1007/s10291-012-0301-9

    View details for Web of Science ID 000324246700011

  • Critical Elements for a Multi-Constellation Advanced RAIM NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Blanch, J., Walter, T., Enge, P., Wallner, S., Fernandez, F. A., Dellago, R., Ioannides, R., Hernandez, I. F. 2013; 60 (1): 53-69

    View details for DOI 10.1002/navi.29

    View details for Web of Science ID 000339565800005

  • Incorporating GLONASS into Aviation RAIM Receivers International Technical Meeting of the Institute-of-Navigation Walter, T., Blanch, J., Choi, M. J., Reid, T., Enge, P. INST NAVIGATION. 2013: 239–249

    View details for Web of Science ID 000327063800022

  • Advanced RAIM System Architecture with a Long Latency Integrity Support Message Blanch, J., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2013: 2605–13

    View details for Web of Science ID 000375213002056

  • Constructing Ionospheric Irregularity Threat Model for Korean SBAS Bang, E., Lee, J., Lee, J., Seo, J., Walter, T., ION INST NAVIGATION. 2013: 296–306

    View details for Web of Science ID 000327064500027

  • Evolution of SBAS: Two Frequencies & Multiple Constellations Walter, T., Inst Navigat INST NAVIGATION. 2013: 2394–2439

    View details for Web of Science ID 000375213002038

  • Qualifying an L5 SBAS MOPS Ephemeris Message to Support Multiple Orbit Classes Reid, T., Walter, T., Enge, P., Inst Navigat INST NAVIGATION. 2013: 825–43

    View details for Web of Science ID 000375213000078

  • Dual Frequency SBAS Trial and Preliminary Results for East-Asia Region Sakai, T., Hoshinoo, K., Walter, T., Inst Navigat INST NAVIGATION. 2013: 912–20

    View details for Web of Science ID 000375213000085

  • The Influence of the Ionosphere on SBAS Walter, T., Inst Navigat INST NAVIGATION. 2013: 2373–93

    View details for Web of Science ID 000375213002037

  • Implementation of the L5 SBAS MOPS Walter, T., Blanch, J., Enge, P., Inst Navigat INST NAVIGATION. 2013: 814–24

    View details for Web of Science ID 000375213000077

  • Optimal Positioning for Advanced Raim NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Blanch, J., Walter, T., Enge, P. 2013; 60 (4): 279-289

    View details for DOI 10.1002/navi.49

    View details for Web of Science ID 000339567500003

  • Near Term Improvements to WAAS Availability International Technical Meeting of the Institute-of-Navigation Blanch, J., Walter, T., Phelts, R. E., Enge, P. INST NAVIGATION. 2013: 71–77

    View details for Web of Science ID 000327063800003

  • L1/L5 SBAS MOPS Ephemeris Message to Support Multiple Orbit Classes International Technical Meeting of the Institute-of-Navigation Reid, T., Walter, T., Enge, P. INST NAVIGATION. 2013: 78–92

    View details for Web of Science ID 000327063800004

  • Signal Deformation Monitoring for Dual-Frequency WAAS International Technical Meeting of the Institute-of-Navigation Phelts, R. E., Wong, G., Walter, T., Enge, P. INST NAVIGATION. 2013: 93–106

    View details for Web of Science ID 000327063800005

  • Results on the Optimal Detection Statistic for Integrity Monitoring International Technical Meeting of the Institute-of-Navigation Blanch, J., Walter, T., Enge, P. INST NAVIGATION. 2013: 262–273

    View details for Web of Science ID 000327063800024

  • Overcoming RFI with High Mask Angle Antennas and Multiple GNSS Constellations Heng, L., Walter, T., Enge, P., Gao, G., Inst Navigat INST NAVIGATION. 2013: 3433–42

    View details for Web of Science ID 000375213003038

  • GPS Signal-in-Space Integrity Performance Evolution in the Last Decade IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Heng, L., Gao, G. X., Walter, T., Enge, P. 2012; 48 (4): 2932-2946

    View details for Web of Science ID 000309865600010

  • Satellite Navigation for Aviation in 2025 PROCEEDINGS OF THE IEEE Blanch, J., Walter, T., Enge, P. 2012; 100: 1821-1830

    View details for DOI 10.1109/JPROC.2012.2190154

    View details for Web of Science ID 000309838000063

  • OPTIMAL POSITIONING FOR ADVANCED RAIM International Technical Meeting (ITM) of the Institute-of-Navigation (ION) Blanch, J., Walter, T., Enge, P. INST NAVIGATION. 2012: 1624–1631

    View details for Web of Science ID 000317865600081

  • The impact the lonosphere on GNSS Aufmentation Walter, T., ION INST NAVIGATION. 2012: 1070–78

    View details for Web of Science ID 000327163301008

  • GLONASS Signal-in-Space Anomalies Since 2009 25th International Technical Meeting of the Satellite-Division of the Institute-of-Navigation Heng, L., Gao, G. X., Walter, T., Enge, P. INST NAVIGATION. 2012: 833–842

    View details for Web of Science ID 000327163300079

  • L1/L5 SBAS MOPS to Support Multiple Constellations 25th International Technical Meeting of the Satellite-Division of the Institute-of-Navigation Walter, T., Blanch, J., Enge, P. INST NAVIGATION. 2012: 1287–1297

    View details for Web of Science ID 000327163301028

  • Measuring Code-Phase Differences due to Inter-Satellite Hardware Differences 25th International Technical Meeting of the Satellite-Division of the Institute-of-Navigation Wong, G., Chen, Y., Phelts, R. E., Walter, T., Enge, P. INST NAVIGATION. 2012: 2150–2158

    View details for Web of Science ID 000327163302018

  • Evaluation of Multi-Constellation Advanced RAIM for Vertical Guidance using GPS and GLONASS Signals with Multiple Faults 25th International Technical Meeting of the Satellite-Division of the Institute-of-Navigation Choi, M., Blanch, J., Walter, T., Akos, D., Enge, P. INST NAVIGATION. 2012: 884–892

    View details for Web of Science ID 000327163300084

  • A Framework for Analyzing Architectures that Support ARAIM 25th International Technical Meeting of the Satellite-Division of the Institute-of-Navigation Walter, T., Blanch, J., Enge, P. INST NAVIGATION. 2012: 2850–2857

    View details for Web of Science ID 000327163302072

  • Automated Verification of Potential GPS Signal-In-Space Anomalies Using Ground Observation Data IEEE/ION Position Location and Navigation Symposium (PLANS) Heng, L., Gao, G. X., Walter, T., Enge, P. IEEE. 2012: 1111–1118

    View details for Web of Science ID 000309273900138

  • Statistical Characterization of GLONASS Broadcast Clock Errors and Signal-In-Space Errors International Technical Meeting (ITM) of the Institute-of-Navigation (ION) Heng, L., Gao, G. X., Walter, T., Enge, P. INST NAVIGATION. 2012: 1697–1707

    View details for Web of Science ID 000317865600087

  • Evolving WAAS to Serve L1/L5 Users NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION Walter, T., Blanch, J., Phelts, R. E., Enge, P. 2012; 59 (4): 317-327

    View details for DOI 10.1002/navi.21

    View details for Web of Science ID 000209006500006

  • Advanced RAIM User Algorithm Description: Integrity Support Message Processing, Fault Detection, Exclusion, and Protection Level Calculation 25th International Technical Meeting of the Satellite-Division of the Institute-of-Navigation Blanch, J., Walter, T., Enge, P., Lee, Y., Pervan, B., Rippl, M., Spletter, A. INST NAVIGATION. 2012: 2828–2849

    View details for Web of Science ID 000327163302071

  • Impact of Personal Privacy Devices for WAAS Aviation Users 25th International Technical Meeting of the Satellite-Division of the Institute-of-Navigation Gao, G. X., Gunning, K., Walter, T., Enge, P. INST NAVIGATION. 2012: 235–241

    View details for Web of Science ID 000327163300022

  • Availability Impact on GPS Aviation due to Strong Ionospheric Scintillation IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Seo, J., Walter, T., Enge, P. 2011; 47 (3): 1963-1973

    View details for Web of Science ID 000293417100028

  • Correlation of GPS signal fades due to ionospheric scintillation for aviation applications ADVANCES IN SPACE RESEARCH Seo, J., Walter, T., Enge, P. 2011; 47 (10): 1777-1788

    View details for DOI 10.1016/j.asr.2010.07.014

    View details for Web of Science ID 000290136900013

  • Evolving WAAS to Serve L1/L5 Users 24th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS) Walter, T., Blanch, J., Phelts, R. E., Enge, P. INST NAVIGATION. 2011: 2495–2504

    View details for Web of Science ID 000304032002057

  • First Signal in Space Analysis of GLONASS K-1 Thoelert, S., Erker, S., Furthner, J., Meurer, M., Gao, G. X., Heng, L., Walter, T., Enge, P., ION INST NAVIGATION. 2011: 3076–82

    View details for Web of Science ID 000304032003014

  • Optimization of a Vertical Protection Level Equation for Dual Frequency SBAS International Technical Meeting of the Institute of Navigation Blanch, J., Walter, T., Enge, P. INST NAVIGATION. 2011: 459–463

    View details for Web of Science ID 000290749900034

  • Statistical Characterization of GPS Signal-In-Space Errors International Technical Meeting of the Institute of Navigation Heng, L., Gao, G. X., Walter, T., Enge, P. INST NAVIGATION. 2011: 312–319

    View details for Web of Science ID 000290749900017

  • Demonstrations of Multi-Constellation Advanced RAIM for Vertical Guidance using GPS and GLONASS Signals 24th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS) Choi, M., Blanch, J., Akos, D., Heng, L., Gao, G., Walter, T., Enge, P. INST NAVIGATION. 2011: 3227–3234

    View details for Web of Science ID 000304032003029

  • SBAS and GBAS Integrity for Non-Aviation Users: Moving Away from "Specific Risk" International Technical Meeting of the Institute of Navigation Pullen, S., Walter, T., Enge, P. INST NAVIGATION. 2011: 533–545

    View details for Web of Science ID 000290749900040

  • Statistical Characterization of GLONASS Broadcast Ephemeris Errors 24th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS) Heng, L., Gao, G. X., Walter, T., Enge, P. INST NAVIGATION. 2011: 3109–3117

    View details for Web of Science ID 000304032003017

  • Breaking the Ice: Navigation in the Arctic 24th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS) Gao, G. X., Heng, L., Walter, T., Enge, P. INST NAVIGATION. 2011: 3767–3772

    View details for Web of Science ID 000304032003081

  • A Proposal for Multi-Constellation Advanced RAIM for Vertical Guidance 24th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS) Blanch, J., Walter, T., Enge, P., Wallner, S., Fernandez, F. A., Dellago, R., Ioannides, R., Pervan, B., Hernandez, I. F. INST NAVIGATION. 2011: 2665–2680

    View details for Web of Science ID 000304032002074

  • Advanced RAIM Demonstration using Four Months of Ground Data International Technical Meeting of the Institute of Navigation Choi, M., Blanch, J., Walter, T., Enge, P. INST NAVIGATION. 2011: 279–284

    View details for Web of Science ID 000290749900014

  • A Clock and Ephemeris Algorithm for Dual Frequency SBAS 24th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS) Blanch, J., Walter, T., Enge, P. INST NAVIGATION. 2011: 2513–2519

    View details for Web of Science ID 000304032002059

  • Bounding Errors Caused by Nominal GNSS Signal Deformations 24th International Technical Meeting of the Satellite Division of the Institute of Navigation (ION GNSS) Wong, G., Phelts, R. E., Walter, T., Enge, P. INST NAVIGATION. 2011: 2657–2664

    View details for Web of Science ID 000304032002073

  • Alternative Characterization of Analog Signal Deformation for GNSS-GPS Satellites International Technical Meeting of the Institute of Navigation Wong, G., Phelts, R. E., Walter, T., Enge, P. INST NAVIGATION. 2011: 497–507

    View details for Web of Science ID 000290749900038

  • Reversion from L1-L5 Dual to L5 Single Frequency WAAS in the Presence of RF Interference IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Jan, S., Walter, T., Enge, P. 2010; 46 (3): 1110-1126

    View details for Web of Science ID 000282954900012

  • RAIM with Optimal Integrity and Continuity Allocations Under Multiple Failures IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Blanch, J., Walter, T., Enge, P. 2010; 46 (3): 1235-1247

    View details for Web of Science ID 000282954900021

  • Unaugmented GPS-Based Flight Inspection System IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Kim, E., Walter, T., Powell, J. D. 2010; 46 (2): 717-724

    View details for DOI 10.1109/TAES.2010.5461646

    View details for Web of Science ID 000277499800016

  • GPS Ephemeris Error Screening and Results for 2006-2009 2010 International Technical Meeting of the Institute-of-Navigation Heng, L., Gao, G. X., Walter, T., Enge, P. INST NAVIGATION. 2010: 1014–1022

    View details for Web of Science ID 000280139100104

  • GPS in Mid-life with an International Team of Doctors Analyzing IIF-1 Satellite Performance and Backward-Compatibility 23rd International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GNSS-2010) Gao, G. X., Heng, L., Wong, G., Phelts, E., Blanch, J., Walter, T., Enge, P., Erker, S., Thoelert, S., Meurer, M. INST NAVIGATION. 2010: 1597–1604

    View details for Web of Science ID 000290734901063

  • Prototyping Advanced RAIM for Vertical Guidance 23rd International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GNSS-2010) Blanch, J., Choi, M. J., Walter, T., Enge, P. INST NAVIGATION. 2010: 285–291

    View details for Web of Science ID 000290734900021

  • GPS Signal-in-Space Anomalies in the Last Decade Data Mining of 400,000,000 GPS Navigation Messages 23rd International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GNSS-2010) Heng, L., Gao, G. X., Walter, T., Enge, P. INST NAVIGATION. 2010: 3115–3122

    View details for Web of Science ID 000290734903013

  • Characterization of Signal Deformations for GPS and WAAS Satellites 23rd International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GNSS-2010) Wong, G., Phelts, R. E., Walter, T., Enge, P. INST NAVIGATION. 2010: 3143–3151

    View details for Web of Science ID 000290734903015

  • Vertical Protection Level Equations for Dual Frequency SBAS 23rd International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GNSS-2010) Walter, T., Blanch, J., Enge, P. INST NAVIGATION. 2010: 2031–2041

    View details for Web of Science ID 000290734902009

  • Coverage Improvement for Dual Frequency SBAS 2010 International Technical Meeting of the Institute-of-Navigation Walter, T., Blanch, J., Enge, P. INST NAVIGATION. 2010: 344–353

    View details for Web of Science ID 000280139100039

  • MATLAB Algorithm Availability Simulation Tool GPS SOLUTIONS Jan, S., Chan, W., Walter, T. 2009; 13 (4): 327-332

    View details for DOI 10.1007/s10291-009-0117-4

    View details for Web of Science ID 000270171300008

  • Compass-M1 Broadcast Codes in E2, E5b, and E6 Frequency Bands IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING Gao, G. X., Chen, A., Lo, S., De Lorenzo, D., Walter, T., Enge, P. 2009; 3 (4): 599-612

    View details for DOI 10.1109/JSTSP.2009.2025635

    View details for Web of Science ID 000268377200006

  • Characteristics of deep GPS signal fading due to ionospheric scintillation for aviation receiver design RADIO SCIENCE Seo, J., Walter, T., Chiou, T., Enge, P. 2009; 44

    View details for DOI 10.1029/2008RS004077

    View details for Web of Science ID 000268095500003

  • Hysteresis in RAIM 22nd International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GNSS-09) Blanch, J., Mayer, C., Lo, S., Walter, T., Enge, P. INST NAVIGATION. 2009: 2818–2823

    View details for Web of Science ID 000284356202085

  • Availability Benefit of Future Dual Frequency GPS Avionics under Strong Ionospheric Scintillation 22nd International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GNSS-09) Seo, J., Walter, T., Enge, P. INST NAVIGATION. 2009: 1216–1224

    View details for Web of Science ID 000284356201026

  • Methodology and Case Studies of Signal-in-Space Error Calculation Top-down Meets Bottom-up 22nd International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GNSS-09) Gao, G. X., Tang, H., Blanch, J., Lee, J., Walter, T., Enge, P. INST NAVIGATION. 2009: 2824–2831

    View details for Web of Science ID 000284356202086

  • Characterizing Nominal Analog Signal Deformation on GNSS Signals 22nd International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GNSS-09) Phelts, R. E., Walter, T., Enge, P. INST NAVIGATION. 2009: 1343–1350

    View details for Web of Science ID 000284356201038

  • Evaluation of Signal in Space Error Bounds to Support Aviation Integrity 22nd International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GNSS-09) Walter, T., Blanch, J., Enge, P. INST NAVIGATION. 2009: 1317–1329

    View details for Web of Science ID 000284356201036

  • Bounding higher-order ionosphere errors for the dual-frequency GPS user RADIO SCIENCE Datta-Barua, S., Walter, T., Blanch, J., Enge, P. 2008; 43 (5)

    View details for DOI 10.1029/2007RS003772

    View details for Web of Science ID 000259992300001

  • Altitudinal variation of midlatitude localized TEC enhancement from ground- and space-based measurements SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS Datta-Barua, S., Mannucci, A. J., Walter, T., Enge, P. 2008; 6 (10)

    View details for DOI 10.1029/2008SW000396

    View details for Web of Science ID 000259992500001

  • Position Error Bound Calculation for GNSS using Measurement Residuals IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Blanch, J., Walter, T., Enge, P. 2008; 44 (3): 977-984

    View details for Web of Science ID 000260332000011

  • Wide area augmentation system-based might inspection system JOURNAL OF AIRCRAFT Kim, E., Walter, T., Powell, J. D. 2008; 45 (2): 614-621

    View details for DOI 10.2514/1.32531

    View details for Web of Science ID 000254761600029

  • Improving GPS-based landing system performance using an empirical barometric altimeter confidence bound IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS Jan, S., Gebre-Egziabher, D., Walter, T., Enge, P. 2008; 44 (1): 127-146

    View details for Web of Science ID 000255466000011

  • Future Architectures to Provide Aviation Integrity 2008 National Technical Meeting of the Institute-of-Navigation Walter, T., Blanch, J., Enge, P., Pervan, B., Gratton, L. INST NAVIGATION. 2008: 394–401

    View details for Web of Science ID 000279793700034

  • Compass-M1 Broadcast Codes and Their Application to Acquisition and Tracking 2008 National Technical Meeting of the Institute-of-Navigation Gao, G. X., Chen, A., Lo, S., De Lorenzo, D., Walter, T., Enge, P. INST NAVIGATION. 2008: 133–141

    View details for Web of Science ID 000279793700007

  • Understanding the GIOVE-B Broadcast Codes of the Galileo System 42nd Asilomar Conference on Signals, Systems and Computers Gao, G. X., Akos, D., Walter, T., Enge, P. IEEE. 2008: 2086–2090

    View details for Web of Science ID 000274551001180

  • Understanding PHMI for Safety of Life Applications in GNSS 2007 National Technical Meeting of the Institute-of-Navigation Blanch, J., Walter, T., Enge, P. INST NAVIGATION. 2007: 305–310

    View details for Web of Science ID 000279780100024

  • Adaptive Carrier Smoothing Using Code and Carrier Divergence 2007 National Technical Meeting of the Institute-of-Navigation Kim, E., Walter, T., Powell, J. D. INST NAVIGATION. 2007: 141–152

    View details for Web of Science ID 000279780100007

  • Model Analysis on the Performance for an Inertial Aided FLL-Assisted-PLL Carrier-Tracking Loop in the Presence of Ionospheric Scintillation 2007 National Technical Meeting of the Institute-of-Navigation Chiou, T., Gebre-Egziabher, D., Walter, T., Enge, P. INST NAVIGATION. 2007: 1276–1295

    View details for Web of Science ID 000279780100132

  • Galileo GIOVE-A Broadcast E5 Codes and their Application to Acquisition and Tracking 2007 National Technical Meeting of the Institute-of-Navigation Gao, G. X., De Lorenzo, D. S., Chen, A., Lo, S. C., Akos, D. M., Walter, T., Enge, P. INST NAVIGATION. 2007: 936–946

    View details for Web of Science ID 000279780100097

  • Bounding Higher Order Ionosphere Errors for the Dual Frequency GPS User 19th International Technical Meeting of the Satellite Division of the Institute-of-Navigation Datta-Barua, S., Walter, T., Blanch, J., Enge, P. INST NAVIGATION. 2006: 1377–1392

    View details for Web of Science ID 000279025901061

  • Optimizing WAAS Accuracy/Stability For a Single Frequency Receiver Kim, E., Walter, T., Powell, J., NAVSTAR INST NAVIGATION. 2006: 962–70

    View details for Web of Science ID 000279025901018

  • Code Generation Scheme and Property Analysis of Broadcast Galileo L1 and E6 Signals 19th International Technical Meeting of the Satellite Division of the Institute-of-Navigation Gao, G. X., Spilker, J., Walter, T., Enge, P., Pratt, A. R. INST NAVIGATION. 2006: 1526–1534

    View details for Web of Science ID 000279025901076

  • Field Data Analysis for a Range-Based Local Airport Monitor for WAAS 2006 National Technical Meeting of the Institute-of-Navigation Seo, J., Rife, J., Pullen, S., Walter, T., Enge, P. INST NAVIGATION. 2006: 748–758

    View details for Web of Science ID 000279767800070

  • A development of WAAS-aided Flight Inspection Truth System 2006 IEEE/ION POSITION, LOCATION AND NAVIGATION SYMPOSIUM, VOLS 1-3 Kim, E., Peled, U., Walter, T., Powell, J. D. 2006: 61-70

    View details for Web of Science ID 000241665600009

  • Galileo-GPS RAIM for Vertical Guidance 2006 National Technical Meeting of the Institute-of-Navigation Ene, A., Blanch, J., Walter, T. INST NAVIGATION. 2006: 432–440

    View details for Web of Science ID 000279767800039

  • WAAS-based threat monitoring for a Local Airport Monitor (LAM) that supports Category I Precision Approach IEEE/ION Position, Location, and Navigation Symposium Rife, J., Pullen, S., Walter, T., Phelts, E., Pervan, B., Enge, P. IEEE. 2006: 468–482

    View details for Web of Science ID 000241665600056

  • A Reference Point-based Precise Relative Positioning Method Using a Single Frequency Receiver 2006 National Technical Meeting of the Institute-of-Navigation Kim, E., Walter, T., Powell, J. D. INST NAVIGATION. 2006: 283–292

    View details for Web of Science ID 000279767800025

  • Ionospheric correction using tomography 10th International Technical Meeting of the Satellite Division of the Institute-of-Navigation Hansen, A. J., Walter, T., Enge, P. INST NAVIGATION. 1997: 249–257

    View details for Web of Science ID 000073331000026

  • High integrity multipath mitigation techniques for ground reference stations 10th International Technical Meeting of the Satellite Division of the Institute-of-Navigation Dai, D. H., Walter, T., Comp, C. J., Tsai, Y. J., Ko, P. Y., Enge, P., Powell, J. D. INST NAVIGATION. 1997: 593–604

    View details for Web of Science ID 000073331000059

  • Improving WAAS integrity and availability: UDRE and GIVE time updates 10th International Technical Meeting of the Satellite Division of the Institute-of-Navigation COMP, C., Gazit, R., Walter, T., Enge, P. INST NAVIGATION. 1997: 1315–1324

    View details for Web of Science ID 000073331000138

  • A proposed integrity equation for WAAS MOPS 10th International Technical Meeting of the Satellite Division of the Institute-of-Navigation Walter, T., Enge, P., Hansen, A. INST NAVIGATION. 1997: 475–484

    View details for Web of Science ID 000073331000048

  • Comparison of master station and user algorithms for wide-area augmentation system JOURNAL OF GUIDANCE CONTROL AND DYNAMICS Kee, C., Walter, T., Chao, Y. C., Tsai, Y. J., Enge, P., Parkinson, B. W. 1997; 20 (1): 170-176

    View details for Web of Science ID A1997WC64500024

  • Ionospheric estimation and integrity threat detection ION National Meeting on Navigation and Positioning in the Information Age Hansen, A. J., Chao, Y. C., Walter, T., Enge, P. INST NAVIGATION. 1997: 883–889

    View details for Web of Science ID 000071004000086

  • Integration of wide area DGPS with local area kinematic DGPS IEEE 1996 Position Location and Navigation Symposium (PLANS 96) LAWRENCE, D., Evans, J., Chao, Y. C., Tsai, Y. J., Cohen, C., Walter, T., Enge, P., Powell, J. D., Parkinson, B. I E E E. 1996: 523–529

    View details for Web of Science ID A1996BF52A00077

  • Quality control algorithms on Wide-area Reference Station for WAAS 52nd Annual Meeting of the Institute-of-Navigation on Navigational Technology for the 3rd Millenium Kee, C., Walter, T., Enge, P., Parkinson, B. INST NAVIGATION. 1996: 487–495

    View details for Web of Science ID A1996BJ47X00054

  • Generation of ionospheric correction and confidence estimates for WAAS 52nd Annual Meeting of the Institute-of-Navigation on Navigational Technology for the 3rd Millenium Chao, Y. C., Tsai, Y. J., Evans, J., Kee, C., Walter, T., ENGE, P. K., Powell, J. D., Parkinson, B. W. INST NAVIGATION. 1996: 139–146

    View details for Web of Science ID A1996BJ47X00017

  • Validation or the RTCA message format for WAAS 8th International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GPS-95) Tsai, Y. J., Enge, P., Chao, Y. C., Walter, T., Kee, C. D., Evans, J. INST NAVIGATION. 1995: 661–670

    View details for Web of Science ID A1995BE72A00072

  • Observed GPS signal continuity interruptions 8th International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GPS-95) COBB, H. S., LAWRENCE, D., Christie, J., Walter, T., Chao, Y. C., Powell, J. D., Parkinson, B. INST NAVIGATION. 1995: 793–795

    View details for Web of Science ID A1995BE72A00085

  • A low temperature gyroscope clock for gravitational redshift experiments XXXth Rencontres de Moriond on Dark Matter in Cosmology, Clocks and Tests of Fundamental Laws Buchman, S., Turneaure, J. P., Walter, T., Everitt, C. W. EDITIONS FRONTIERES. 1995: 429–436

    View details for Web of Science ID A1995BG71M00045

  • An algorithm for inter-frequency bias calibration and application to WAAS ionosphere modeling 8th International Technical Meeting of the Satellite Division of the Institute-of-Navigation (ION GPS-95) Chao, Y. C., Tsai, Y. J., Walter, T., Kee, C. D., Enge, P., Parkinson, B. INST NAVIGATION. 1995: 639–646

    View details for Web of Science ID A1995BE72A00070

  • CHARACTERIZING FREQUENCY STABILITY - A CONTINUOUS POWER-LAW MODEL WITH DISCRETE SAMPLING IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT WALTER, T. 1994; 43 (1): 69–79

    View details for DOI 10.1109/19.286357

    View details for Web of Science ID A1994NQ12800013

  • FLIGHT TRIALS OF THE WIDE AREA AUGMENTATION SYSTEM (WAAS) 7th International Technical Meeting of the Satellite-Division of the Institute-of-Navigation (ION GPS-94) Walter, T., Kee, C., Chao, Y. C., Tsai, Y. J., PELED, U., Ceva, J., Barrows, A., Abbot, E., Powell, J. D., Enge, P., Parkinson, B. INST NAVIGATION. 1994: 1537–1546

    View details for Web of Science ID A1994BC96F00169

  • AUTONOMOUS INTEGRITY MONITORING AND WIDE AREA DGPS 1994 National Technical Meeting on Navigating the Earth and Beyond Walter, T., Pervan, B., Enge, P., HERENDEEN, J., Levin, P. L. INST NAVIGATION. 1994: 155–163

    View details for Web of Science ID A1994BC49J00020

  • DISCRETE SIMULATION OF POWER-LAW NOISE KASDIN, N. J., WALTER, T., IEEE I E E E. 1992: 274–83

    View details for DOI 10.1109/FREQ.1992.270003

    View details for Web of Science ID A1992BY55T00041

  • AN ULTRA HIGH-VACUUM LOW-TEMPERATURE GYROSCOPE CLOCK 19TH INTERNATIONAL CONF ON LOW TEMPERATURE PHYSICS ( LT-19 ) Walter, T., Turneaure, J. P., Buchman, S., Everitt, C. W., Keiser, G. M. ELSEVIER SCIENCE BV. 1990: 155–156

    View details for Web of Science ID A1990ED91500079

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