LOGAN SCOTT
CONSULTING
Logan Scott: Principal
Fort Collins, Colorado
Contact me at
http://logan.scott.home.comcast.net/
EXPERTISE
GPS
Indoor GPS / Assisted GPS
Radar
Cellular Telephony (GSM, CDMA, 3G)
Spread Spectrum
Satellite Communications
Emitter Location
RF Signal Processing
CAPABILITIES
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 31 U.S.
patents with several pending.
EXPERIENCE
Independent
consultant since 1991, currently active in
adaptive array signal processing, alternative navigation system
technologies, Assisted-GPS,
location based encryption, and, teaching continuing education short
courses at
Navtech Seminars, George Washington University & University of
Colorado.
Since graduating from Columbia University in 1978 was with Texas
Instruments until 1991 except for one year with E-Systems. During this
time 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.
2003-Present:
Working with
Lonestar Aerospace, Veroscan & Incucomm developing a variety of
RFID
projects for medical & military applications.
2001-Present:
Partner in
GeoCodex LLC developing location based encryption for digital cinema
distribution, secure VPN, and SCADA systems. Primary role is providing
indoor
GPS expertise and evaluation.
2001-Present:
Providing rapid
turn around technical due diligence for venture capital firms Apax
Partners,
Incucomm, and, Carrilon.
1991
‑ Present:
Teaching
continuing education short courses with 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 has been 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.
2003-Present: Developed GPS/Adaptive Array simulation for use
in
evaluating JPALS RTK performance in jamming & multipath. Particular
emphasis
was on modeling the effects of beamforming adaptive systems on
code
and carrier phase observables
2001-Present: Partner in GeoCodex LLC developing location
based encryption for digital cinema distribution and secure VPN.
Primary role
is providing indoor GPS expertise and evaluation.
2001-Present: Providing rapid turn around technical due
diligence for venture capital firms Apax Partners, Incucomm, and,
Carrilon..
1999-2003: Assisting CRS Inc. in developing software based GPS
receivers. Specific responsibilities include developing and evaluating
algorithms, providing technical assistance, product marketing, and
writing proposals.
1991-Present: Teaching continuing education short courses with
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.
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 pioneers
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 1990 - 1994: Consulting Engineer on proprietary program
developing high performance multirate algorithmic/processing
architectures for array sensor system.
July 1989 - August 1991: Consulting Engineer to several radar
and communications programs providing waveform design/signal processing
approaches. Among completed trade studies:
- Completed study to identify Wavelet transform applications in
RF and Image processing. Led to multiband RF channelizer approach based
on
multirate Quadrature Mirror lattice filter formulation of the Wavelet
transform.
- Analyzed performance and hardware implications of alternative
radar waveforms for tracking applications. Using a combination of PRF
modulation and pulse compression, was able to place most target returns
in the clear thereby significantly extending maximum range. Compression
approaches examined included biphase, polyphase, quadraphase (MSK),
LFM, NLFM, and Costas/Extended Linear Congruence compression techniques
with both matched and mismatched filters for temporal sidelobe
reduction.
- Developed sidelobe canceller approach using Modified
Gram-Schmidt algorithms to rapidly cancel interference in a clutter
contaminated environment while maintaining required low sidelobe
performance. Solved overdefinition problem using directive subarray
structure combined with residuals monitoring.
- Developed LPI/AJ Com/Nav architecture for Intraflight
Positioning System that considered channel effects, intercept receiver
design factors, FEC/ARQ EDAC alternatives, power and antenna
management, network protocols, and alternative M-ary orthogonal
waveform design approaches.
- Designed set of alternative IFF Mode 4 waveforms to provide
cryptographic capability of new Mark 15 waveforms while retaining
compatibility with
older Mark 12 transponders. Made tradeoffs between 28 approaches
ranging
from minimal DPSK approaches on up to approaches using 4-d 8-PSK with
rotational
invariant 256 state Wei Trellis codes.
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, nonuniform 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: 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.
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 F111 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, bitsynchronization
algorithms, spread spectrum
signal acquisition approaches, signal to noise ratio estimators, and
adaptive
array ECCM.
EDUCATION
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.
PATENTS (31 Total)
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
PUBLICATIONS (Available On Request)
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 to be presented at 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-Encyption;
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
PROFESSIONAL ASSOCIATIONS
Member, IEEE
Member, ION
Navtech Technical Advisory Board