Logan Scott: Principal
Fort Collins, Colorado
Contact me at
Indoor GPS / Assisted GPS
Radar & RFID Signal Processing
Cellular Telephony (GSM, CDMA, 3G)
RF Signal Processing
Systems/Signal Processing consultant providing innovative approaches and solutions to building advanced RF systems including Communications, Navigation, RFID, Radar, and Emitter Location Systems. Equipped with an extensive knowledge of signal processing techniques, and, a firm grounding in hardware/software design options; will perform architectural tradeoffs and definitions as well as a provide leadership role in performance analysis and simulation efforts. Extensive experience in proposal and technical writing as well as public speaking and expert witness experience. Named one of "50+ Leaders to Watch" by GPS World magazine in 2006. Uses MATLAB & Excel as primary analysis tools.
Holder of 33 U.S. patents with several pending.
Independent consultant since 1991, currently active in adaptive array signal processing, alternative navigation system technologies, Assisted-GPS, location based encryption, RFID, and, teaching continuing education short courses at Navtech Seminars, George Washington University & University of Colorado.
2008-Present: Assisting small companies developing X band and Ku band FMCW and short range radar systems for collision avoidance systems and for machine vibration monitoring. Developing Matlab based signal processing algorithms for target detection and characterization. Advising on hardware selection and systems architectures.
2003-Present: Providing GPS, communications and radar expertise to the legal community seeking to assert and defend intellectual property rights. Active in patent claims analysis, claims constructions, prior art searches, infringement determinations, and writing tutorials explaining patent teachings.
2003-Present: Working with Lonestar Aerospace, Veroscan & Incucomm developing a variety of RFID projects for medical & military applications. Originated use of correlation based techniques for detecting RFID tags lost inside patients using higher power interrogations.
2001-Present: Partner in GeoCodex LLC developing location signature based encryption/decryption methods for digital cinema distribution, location secure databases, and SCADA systems.
2001-Present: Providing rapid turnaround technical due diligence for venture capital firms Apax Partners, Incucomm, and, Carrilon.
1991-Present: Teaching continuing education short courses I developed for Navtech Seminars, George Washington University & University of Colorado in the United States and Europe. Subjects taught include Introduction to GPS, RF Interference Mitigation, New GPS Signal Structures, and, Frequency Hopping systems. Navtech’s Technical Advisor for New Signals & Processing.
2004-2006: Developed high accuracy phased array / GPS receiver simulation for ARINC in support of JPALS technology development effort. Particular emphasis placed on modeling adaptive array effects on GPS signal tracking and upon modeling the effects of multipath. Both BPSK and BOC signal formats have been included so the simulation is suitable for modeling C/A code, Y-code, and M-code signal reception as well as any of the new civil signal formats (L2C and L5) and, any of the formats contemplated for the Galileo system.
1999-2002: Assisted CRS Inc. in developing software based GPS receivers. Specific responsibilities included developing and evaluating algorithms, providing technical assistance, product marketing, and writing proposals.
1999-2001: Assisted Interdigital in developing interference threat models for 3G cellular systems (TDD-WCDMA).
August 1991-2000: Helped Omnipoint/XIRCOM in developing PCS system architectures. Responsible for signaling protocol designs, performance/business analysis of competitor systems (EIA/TIA-95 CDMA, GSM, GPRS, EGPRS, IS-136, IMT-2000, PACS, DECT, and proposed 3rd Generation Air Interfaces and System Architectures), interference analysis, waveform design, deployment strategy, and, standards committee support. Wrote technical portions of winning pioneer’s preference license application for New York 30 MHz MTA; estimated value: $500 million US.
2000-2001: Evaluated alternative systems (802.11b, Breezecom, Adaptive Broadband) for unlicensed wireless Internet Service Provider in terms of coverage, performance, and cost. Wrote MATLAB propagation analysis package accounting for antenna patterns, tilt, tower height & RF propagation factors.
November 1999: Developed MATLAB based WAAS/GPS signal cross correlation analysis package to evaluate WAAS interference potential as a function of Doppler offset, predetection integration time, Gold codes used, relative signal strength, and specific symbol patterns.
March 1999: Examined possible use of block Turbo-code for GPS L5 signal structure and found 2.2 dB tracking threshold advantage compared with current baseline signal structure.
August 1998: Wrote MATLAB based GPS/GLONASS/INMARSAT-3 satellite orbit simulator for evaluation of dilution of precision parameters affecting navigation accuracy performance as a function of user position and receiver tracking capabilities. Later, used this program as the basis for evaluating foreign navigation systems performance.
August 1991-1994: Consulting Engineer on proprietary Texas Instruments program developing high performance multi-rate algorithmic/processing architectures for array sensor system.
Worked as a signal processing specialist and RF systems architect, eventually becoming youngest Senior Member of Technical Staff at Texas Instruments at age 30. Primary association was with Global Positioning System programs, but supported several other programs in a consulting role.
July 1989-August 1991: Advisor to several radar and communications programs providing waveform design/signal processing approaches.
June 1984-July 1989: Lead GPS Systems Engineer for team developing advanced Global Positioning System (GPS) based navigation systems. Responsible for hardware architecture and digital signal processing; my efforts concentrated on developing approaches for building high performance, jamming resistant digital GPS receivers using large scale ASIC and GaAs technologies. Developed gain and frequency plans, non-uniform A/D conversion techniques, channel on a chip architectures, baseband signal processing algorithms and assessed adaptive array tradeoffs. As chief theoretician on the team, guided efforts of signal processing analysts performing supporting trade studies.
These efforts formed basis for $20,000,000 win from DARPA and positioned TI for win on $500,000,000 proprietary program. Eight patent disclosures resulted from this work and in 1988 was elected Senior Member of Technical Staff, a position restricted to less than 12% of Texas Instrument's technical population.
June 1984-May 1985: Lead GPS Receiver Systems Engineer for Range Applications program proposal effort. Responsible for all phases of receiver performance analysis/simulation as well as customer presentations showing various options.
August 1983-June 1984: Was at E-Systems (see below)
Sept 1981-August 1983: G/AIT Receiver Analyst for the Ground/Airborne IONDS Terminal proposal effort. Responsible for developing and simulating communications signal processing approaches applicable to a fading, nuclear disturbed channel environment. As part of this effort, I developed the concept of fade resistant GPS receivers, a major factor in Texas Instrument's winning this $100,000,000 program.
April 1982-Sept. 1982: Analyst, IFF Mark 15 Program Wrote a package of FORTRAN programs to analyze the performance of candidate IFF signal structures during jamming. Analysis included queuing effects, coding gains, preamble recognition algorithms, ISLI processing, and effects of several types of jammer.
May 1979-Nov. 1979: Terrain Following Radar Analyst As part of an F‑111 ECM upgrade effort, evaluated the effectiveness of adaptive sidelobe cancellation schemes against jammers. Developed an auxiliary antenna approach that eliminates adaptation induced boresight shift errors in difference channels of monopulse radar systems.
June 1978-Sept 1981: Member, GPS Signal Processing Group Responsible for development and analysis of a variety of algorithms including, phaselock loops, delaylock loops, bit-synchronization algorithms, spread spectrum signal acquisition approaches, signal to noise ratio estimators, and adaptive array ECCM.
Signal processing algorithm development for Electronic Warfare programs
August 1983-June 1984: Senior Engineering Analyst While at E-Systems, was part of the INEWS proposal team responsible for developing the proposed system's overall architecture. In the course of this work, gained experience with Angle Of Arrival based RF detection and recognition systems, camouflage jamming, retrodirective phased array antennas, and stepped etalon laser detectors.
BSEE 1978, Columbia University, New York, New York. 3.5 GPA
Eta Kappa Nu engineering honor society.
Made Deans List in 5 of 8 semesters.
7,893,840 Interrogator and interrogation system employing the same
7,671,744 Interrogator and interrogation system employing the same
7,512,989 Data loader using location identity to provide secure communication of data to recipient devices
7,501,948 Interrogation system employing prior knowledge about an object to discern an identity thereof
6,839,539 RF signal repeater in mobile communication systems
6,522,642 Antenna diversity techniques
6,501,955 RF signal repeater, mobile unit position determination system using the RF signal repeater, and method of communication therefore
6,388,997 Timing adjustment control for efficient time division duplex communication
6,366,566 Efficient communication system using time division multiplexing and timing adjustment control
6,363,107 Preamble code structure and detection method and apparatus
6,356,607 Preamble code structure and detection method and apparatus
6,154,486 Preamble code structure and detection method and apparatus
6,141,373 Preamble code structure and detection method and apparatus
6,094,421 Timing adjustment control for efficient time division duplex, frequency division duplex or hybrid time division duplex/frequency division duplex communication
6,049,538 Efficient communication system using time division multiplexing and timing adjustment control
6,041,046 Cyclic time hopping in time division multiple access communication system
5,987,079 Preamble code structure and detection method and apparatus
5,959,980 Timing adjustment control for efficient time division duplex communication
5,859,842 Antenna diversity techniques
5,832,022 Method and apparatus for controlling the modulation index of continuous phase modulated (CPM) signals
5,818,371 Coherent synchronization and processing of pulse groups
5,802,046 Efficient time division duplex communication system with interleaved format and timing adjustment control
5,784,403 Spread spectrum correlation using saw device
5,754,584 Non-coherent spread-spectrum continuous-phase modulation communication system
5,745,484 Efficient communication system using time division multiplexing and timing adjustment control
5,742,583 Antenna diversity techniques
5,689,502 Efficient frequency division duplex communication system with interleaved format and timing adjustment control
5,671,219 Communication protocol for spread spectrum communication
5,648,955 Method for power control in a TDMA spread spectrum communication system
5,535,237 Method and system for a multi channel and search global position system signal processor
5,347,284 System and method for a digital navigation satellite receiver
5,245,628 Enhanced L1/L2 code channel for global positioning system receivers
5,185,610 GPS system and method for deriving pointing or attitude from a single GPS receiver
Making the GNSS Environment Hostile to Jammers & Spoofers, invited paper presented at ION-GNSS-2011, September 20-23, 2011
J911: The Case for Fast Jammer Detection and Location Using Crowdsourcing Approaches, paper presented at ION-GNSS-2011, September 20-23, 2011
Expert Advice: Who Won? GPS World Magazine, August 2011. http://www.gpsworld.com/gnss-system/expert-advice-who-won-11920
Civilian GPS Signal in Space Enhancements for AntiSpoofing and Location Authentication, presented at JNC 2011, 28 June, 2011
J911: The Case for Fast Jammer Detection and Location using Crowdsourcing Approaches, presented at JNC 2011, 28 June, 2011
Comments on LightSquared Ancillary Terrestrial Component (ATC) Interference Potential presented April 21, 2011, GPS World Webinar, Filed FCC 10 May,2011
J911: Fast Jammer Detection and Location Using Cell-Phone Crowd-Sourcing in November 2010 issue of GPS World
Directions 2008: Software-Defined Radio Role to Grow in December 2007 issue of GPS World magazine
Expert Advice: Location Assurance in July 2007 issue of GPS World magazine
Why do GNSS Systems Use Circular Polarization Antennas? in April 2007 issue of Inside GNSS magazine
Adaptive Antenna Arrays in April 2006 issue of Inside GNSS magazine
Adaptive Array Processing and Its Effect on Carrier & Code Phase Observables ION-GNSS-2005
Location Based Security McGraw-Hill Yearbook of Science & Technology 2005
Location Based Encryption & Its Role In Digital Cinema Distribution presented at ION-GPS-2003
Anti-Spoofing & Authenticated Signal Architectures for Civil Navigation Systems presented at ION-GPS-2003
Geo-Encryption; Using GPS to Enhance Security in April 2003 issue of GPS World
A Location Based Encryption Technique and Some of Its Applications presented at ION-NTM-2003
Rapid Signal Acquisition Techniques for Civilian & Military User Equipments Using DSP Based FFT Processing presented at ION-GPS-2001
Reconfigurable Dual Frequency Software GPS Receiver and Applications presented at ION-GPS-2001
Open Architecture Dual Frequency Software GPS Receiver and Applications presented at ION-57th Annual Meeting-2001
Mixed urban/suburban propagation measurements for PCS in the OFS band, 44th Vehicular Technology Conference, 1994 IEEE
§ Member, IEEE
§ Member, ION
§ Navtech Technical Advisory Board