GPS Spoofer Localization for PMUs using Multi-Receiver Direct Time Estimation

Bhamidipati, S. and Gao, G.
Citation:

Proceedings of the 30th International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2017), Portland, Oregon, September 2017, pp. 2780-2784.

Visit Publisher Online Entry:
Abstract:

The modern power grid depends on synchronized phasor values obtained from distributed Phasor Measurement Units (PMUs). When the current power system is transferred to an automated smart grid in the future, these PMU measurements are crucial for high-resolution grid state estimation and early-stage detection of destabilizing conditions. Per the IEEE C37.118 standard PMU specifications, the maximum tolerable clock synchronization error between different PMUs should not exceed 26.5 microseconds (for a 60Hz system). The operation of PMU relies on accurate time keeping sources, such as GPS to obtain precise timestamps.

GPS has advantages of providing beyond microsecond level timing accuracy and is freely available to all users. In addition, the GPS constellation has global coverage, which enables network-wide stability monitoring of power grid. However, given the unencrypted nature and low signal power, GPS signals are vulnerable to external timing attacks. The susceptibility of GPS signals to jamming and spoofing leads to potential threats in the power system. Compared to jamming, spoofing is more sophisticated and can be used to manipulate the PMU with wrong time.

The objective of our research is GPS spoofer detection and localization using Multi-Receiver Direct Time Estimation (MRDTE) for PMUs. In this paper, we propose a multi-receiver architecture that simultaneously estimates the spoofer location (if present) and GPS timing (given as input to the PMUs). The underlying algorithm of our approach is based on a novel signal processing technique known as Direct Time Estimation (DTE) that has been proposed and validated in our earlier work using both single and multiple receivers [1]. DTE performs correlations of the incoming signal with the cumulative satellite signal replica for pre-generated set of clock candidates, and then evaluates the maximum likely clock bias and clock drift for the given instant based on the maximal correlation. It works directly in the navigation solution domain without calculating intermediate pseudorange measurements.

Received Best Presentation of the Session Award. 

Publication Status:
Published
Publication Type:
Proceedings
Publication Date:
09/25/2017
Copyright Notice:

This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.

  1. The following copyright notice applies to all of the above items that appear in IEEE publications: "Personal use of this material is permitted. However, permission to reprint/publish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from IEEE."

  2. The following copyright notice applies to all of the above items that appear in ACM publications: "© ACM, effective the year of publication shown in the bibliographic information. This file is the author’s version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in the journal or proceedings indicated in the bibliographic data for each item."

  3. The following copyright notice applies to all of the above items that appear in IFAC publications: "Document is being reproduced under permission of the Copyright Holder. Use or reproduction of the Document is for informational or personal use only."