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This study is aimed at evaluating Global Positioning System (GPS) performance during simplistic GPS spoofing attacks, whereby spoofing is conducted using a standalone GPS simulator, which at present poses the greatest near-term threat. The study is conducted on two handheld GPS receivers; Garmin GPSmap 60CSx (evaluated GPS receiver) and Garmin GPSmap 60CS (reference GPS receiver). Both receivers employ the GPS L1 coarse acquisition (C/A) signal. Varying minimum spoofing signal power levels, times between position fix lost and spoofing, and probable error patterns are observed for different dates and times. This is due to the GPS satellite constellation being dynamic, causing varying GPS satellite geometry over time, resulting in GPS performance being time dependent. Variation in other GPS error parameters, including ionospheric and tropospheric delays, satellite clock, ephemeris and multipath errors, and unintentional signal interferences and obstructions, could have also resulted in the variation of GPS performance. As the spoofing signal power level is increased, probable error values increase due to decreasing carrier-to-noise density (C/N0) levels for GPS satellites tracked by the receiver. For all the readings, the highest probable errors occur at the minimum spoofing power levels. After spoofing takes place, the probable errors reduce to levels that are lower as compared to prior to transmission of the spoofing signal, as at this point, the spoofing signal power levels are relatively large, resulting in high C/N0 levels and hence, improved accuracy. [ABSTRACT FROM AUTHOR]

In this study, Global Positioning System (GPS) simulation is used to evaluate the effect of varying GPS signal power levels on the accuracy of two handheld GPS receivers; Garmin GPSmap 60CSx (evaluated GPS receiver) and Garmin GPSmap 60CS (reference GPS receiver). Both receivers employ the GPS L1 coarse acquisition (C/A) signal. With decreasing GPS signal power level, probable error values increase due to decreasing carrier-to-noise density (C/N0 levels for GPS satellites tracked by the receiver. Varying probable error patterns are observed for readings taken at different locations and times. This is due to the GPS satellite constellation being dynamic, causing varying GPS satellite geometry over location and time, resulting in GPS accuracy being location / time dependent. For all the readings taken, the evaluated GPS receiver recorded lower probable error values as compared to the reference GPS receiver. This occurred as the evaluated GPS receiver has higher receiver sensitivity, and hence, is able to obtain lower position dilution of precision (PDOP) values. In addition, it has lower receiver noise, reducing the value of its user equivalent ranging error (UERE). [ABSTRACT FROM AUTHOR]

In a previous study, the determination of suitable RF detectors for detection of wireless spy devices was conducted via the measurement of two key parameters; operating bandwidth and power level threshold. However, this study was limited to RF detectors with maximum operating frequency of up to 3 GHz (based on provided specifications). This paper is aimed at extending this study to RF detectors with specified maximum operating frequency of at least 6 GHz, which is considered as sufficient to cover standard wireless communications frequencies. Four RF detectors were considered for the study; Lanmda (model LM-DC 2), Skynet (model XB-68), Mini Gadgets (model CD-RFLD) and Comenzi (model RFS-DT1). Each of the evaluated RF detectors has a variable power level threshold. It was found that the Lanmda RF detector has the largest operating bandwidth (14 MHz - 4.85 GHz), followed by the Comenzi (9 MHz - 3.82 GHz) and Mini Gadgets (156 MHz - 3.44 GHz) RF detectors, while the Skynet RF detector has the smallest operating bandwidth (0.3 MHz - 2.91 GHz). It was observed that the evaluated RF detectors have varying power level threshold performances over frequency. The Comenzi RF detector generally has the lowest power level threshold performance over the tested frequencies. However, the Comenzi RF detector's significantly low power level thresholds could render it susceptible to false alarms, and make it difficult to hone in on possible targets. The Lanmda RF detector's power level thresholds make it suitable for the user to sweep the suspected area using its lowest power level threshold, and then, hone in on the target using higher power level thresholds. Furthermore, its larger operating bandwidth allows it to detect a wider range of signal frequencies. It should be noted that while this operating bandwidth is sufficient to cover most commonly used wireless communications frequencies, it is unsuitable for detection of the increasingly popular 5 and 5. 8 GHz communications frequencies. [ABSTRACT FROM AUTHOR]

In December 2010 to February 2011, the Instrumentation & Electronics Technology Division (BTIE) conducted a series of tests to measure the operating bandwidth and power level threshold of two RF detectors; HomeSafe (model 790) and Ghost (model CT-AS0039). It was determined that the Ghost RF detector's Channel A has the largest operating bandwidth (0.3 MHz to 4.84 GHz), followed by its Channel B (0.4 MHz to 4.35 GHz), while the HomeSafe RF detector has the smallest operating bandwidth (91 MHz to 3.88 GHz). The HomeSafe RF detector has the lowest power level thresholds for the frequency range of approximately 0.7 to 2.9 GHz, while the Ghost RF detector's Channel A has the lowest power thresholds for the remaining tested frequencies. The Ghost RF detector's Channel A also generally has the most stable power level thresholds over the frequencies. Based on the results obtained, the Ghost RF detector is more suitable for detection of wireless spy devices as it can allow for the detection of a wider range of signal frequencies. In addition, its two power level threshold channels, Channel A with lower power level threshold for detection of low power level signals, and Channel B with higher power level threshold to avoid false alarms, allows the user to sweep the suspected area using Channel A, and then, hone in on the target using Channel B. [ABSTRACT FROM AUTHOR]

In order to study the effect of radio frequency interference (RFI) on the global positioning system (GPS) L1 coarse acquisition (C/A) signal, the Instrumentation & Electronics Technology Division (BTIE), Science & Technology Research Institute for Defence (STRIDE), conducted a series of tests specifically aimed at evaluating the minimum interference signal power levels required to jam various GPS receivers. However, interference signals with power levels below the minimum jamming threshold could still severely distort GPS accuracy, rendering it useless for applications requiring high precision. BTIE conducted a test on 8th April 2010 to evaluate the effect of RFI on the accuracy of a Garmin GPS map 60CSx handheld receiver, which employs the GPS L1 C/A signal. As expected, the probable error values of the location fixes increased as the transmuted interference signal power level was increased, until the GPS receiver was completely jammed. The amount of increase of probable error values and the minimum jamming power levels varied significantly based on GPS coverage and various error parameters, including ionospheric and tropospheric delays, and satellite clock, ephemeris and multipath errors. On the whole, this test has demonstrated the disadvantages of field global navigation satellite system (GNSS) evaluations; without the ability to control the various GNSS error parameters, it is difficult to effectively study the effect of any particular error parameter, in the case of this test, interference, on GNSS accuracy. This highlights the importance of using a GNSS simulator for such tests, whereby the tests could be done under repeatable user-controlled conditions. [ABSTRACT FROM AUTHOR]