1. Resume of David Stelpstra
Geodetic engineer (MSc) with over 25 years of experience in positioning for mobile
platforms with an emphasis on GNSS. Analytical and creative thinker and problem
solver with an eye for business values. Experienced in working in a multicultural envi-
ronment. Good at explaining difficult subjects and sharing knowledge.
Personal details
Name David Stelpstra
Address Pastoor Jansenstraat 2
1382 XN Weesp
Telephone +31 (0)294 769 027
+31 (0)6 4431 4285
E-mail david.stelpstra@tomtom.com
Nationality Dutch
Specialties
◦ Geodesy, navigation and high precision (GNSS) positioning.
◦ Integrated navigation systems and Kalman filters
◦ Least squares, statistics and quality control
◦ Numerical analysis and numerical algoritms
◦ Assisted GNSS (AGNSS)
◦ GNSS raw data processing and analysis
◦ Data visualization
Education
1990 MSc in geodesy at Delft University of Technology, faculty of Geodesy (Nether-
lands). Advisor Prof. Dr. Ing. R. Rummel. Title of the graduation thesis: Gravity
recovery from satellite gradiometry. This work treats the recovery of the potential
coefficients of the earths gravity field from simulated observations. By exploiting the
mathematical structure of the problem and by optimizing the algorithms for use on a
CONVEX vector-computer, the set of equations (more than 32000 unknowns) could
be solved efficiently.
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2. Resume of David Stelpstra 2
Professional experience
2003 – Present Senior software engineer at TomTom.
◦ Development of navigation devices with integrated (MEMS) inertial sensors like
accelerometers and rate gyro’s. This covers algorithm design and implementa-
tion for sensor fusion, the use of Pulse per second (PPS) signals for time syn-
chronization of sensors and advice on Linux kernel drivers.
◦ GNSS receiver integration including implementation of Assisted GNSS services.
Working together with receiver manufacturers to identify firmware problems and
improvements.
◦ GNSS quality assessment, such as position deviations, position latency and Time
To First Fix (TTFF). Developments for the use of a high precision reference
system to quantify receiver performance in drive tests.
◦ Use of GNSS simulator and Record and Playback devices. This comprises test-
ing for leap second events, leap years.
1992 – 2002: Software and installation engineer with Quality Positioning Services
(QPS).
◦ Design and development of high precision real time navigation software, based
on the integration of different kinds of navigation sensors (radio positioning sys-
tems, satellite navigation systems, underwater acoustical navigation systems and
Inertial measurement units (IMU)).
◦ Design and implementation of the industry standard for multi reference stations
DGPS positioning. The Delft B-method of testing is used for quality control of
DGPS positioning with multiple reference stations.
◦ Design of software and procedures for the handling of multi beam echo sounder
data and the generation of Digital Elevation Models (DEM) from this data. Also
the integration in the clients work procedures is considered.
◦ In the course of these activities, the software was supported in a wide range
of related activities: lectures on quality control, installation and support of the
soft– and hardware on board of the vessels, user training and support and trouble
shooting.
1990 – 1992: Scientific researcher at the Delft University of Technology (DUT), with
Prof. Dr. Ir. P.J.G. Teunissen, section Mathematical Geodesy and Point positioning, in
the field of (D)GPS-navigation. Model development and software implementation for
satellite navigation.
1989: Development of a program for geodetic network adjustment. Advanced
techniques (among them sparse matrix techniques) were used for solving the large
systems of linear equations on the PC’s from that time.
1984 – 1985: Assistant at the cartography department of the DUT. Technical support
of the cartography course. Installation of the software (GIMMS) used for this and the
use of the software with the practical works of the students.
1983 – 1984: Assistant Satellite geodesy at DUT. Among others the development of
software for the optimization of campaigns to measure tectonic movements.

3. Resume of David Stelpstra 3
Professional development
2015 Institute of Navigation GNSS+ 2015 conference
2014 Workshop satellite navigation, new developments organized by the Netherlands
Institute of Navigation (NIN). Overview of GNSS modernization and new satellite
systems.
2014 Leading SAFe course by the Scaled Agile Academy. Certified as a Scaled Agile
Framework Agilist (SA).
2013 Positioning training by Berman Consulting and Training. The course presented
the fundamentals of inertial sensor integration into navigation systems.
2012 Design Patterns for C++ and Java Developers by Info Support. This course
presented Design Patterns and their use in Object Oriented Programming.
2011 Advanced strapdown inertial navigation analytics course by Applied Strapdown
Analytics, The course covered the analytics associated with strapdown inertial
navigation software, system testing software, and performance analysis of strapdown
inertial navigation systems.
2009 Institute of Navigation GNSS 2009 conference
2008 Institute of Navigation GNSS 2008 conference
2006 Institute of Navigation GNSS 2006 conference
2004 Institute of Navigation GNSS 2004 conference
2001 European Summer school Principles of multi resolution in geometric modeling
(München, August 2001). A ten day summer school to present the state of the art of
geometric modeling, organized as part of the European MINGLE project.
1995 Post academic course: International school GPS for Geodesy (Delft, march
1995). Review of the state of the art of geodetic point positioning using GPS, with an
accent on the use of phase observations.
Software knowledge
Operating systems: Linux, embedded Linux, Android, Unix, Windows, VAX/VMS.
Programming languages: C/C++, Python (NumPy/SciPy), Unix scripting, Matlab,
FORTRAN.
Miscellaneous: TEX/ LATEX, Microsoft office, Microsoft visual studio.
Agile software development using scrum and kanban.
Version control systems and continuous integration.
Scientific Publications
R. Koop and D. Stelpstra, (1989) On the computation of the gravitational potential and
its first and second order derivatives. Manuscripta Geodaetica, Vol 14, 373-382.
R. Koop and D. Stelpstra (1991), Potential coefficient recovery from the csr set of sim-
ulated satellite gradiometry observations. Geophysical Research Letters, Vol 18, no
10, 1897-1900.
D. Stelpstra (2000), Series technical measurements: Tunnel element placement with
QINSy (in Dutch). Geodesia, 2000, nr: 12, 555-558.