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James L Farrell author of GNSS Aided Navigation and Tracking

James L Farrell author of GNSS Aided Navigation and Tracking

GNSS Aided Navigation & Tracking

Dr. Farrell has many decades of experience in this subject area; in the words of one reviewer, the book is “teeming with insights that are hard to find or unavailable elsewhere.”

An engineer and former university instructor, Farrell has made a number of contributions to multiple facets of navigation. He is also the author of Integrated Aircraft Navigation (1976; five hard cover printings; now in paperback) plus over a hundred journal or conference manuscripts and various columns. Frequent aiding-source updates, in applications that require precise velocity rather than extreme precision in position, enables integration to be simplified. All aspects of integration are covered, all the way from raw measurement pre-processing to final 3-D position/velocity/attitude, with far more thorough backup and integrity provisions. Extensive experimental results illustrate the attainable accuracies (cm/s RMS velocities in three-dimensions) during flight under extreme vibration.


This book provides several flight-validated formulations and algorithms, in use but not yet widely because of their originality. Considerable opportunity is therefore offered in multiple areas including:

  • full use of highly intermittent ambiguous carrier phase
  • rigorous integrity for separate SVs
  • unprecedented robustness and situation awareness
  • high performance from low-cost IMUs
  • “cookbook” steps
  • new interoperability features
  • new insights for easier implementation.

 

It is our hope that you will find the new redesigned mobile website more informative and user friendly than our past one. Our intention is to offer visitors a fast loading, mobile ready, intuitive navigation and informative environment with not only factual and intense researched documents but video-driven information covering a broad spectrum of topics in specific areas including navigation, communication, data integrity, and tracking, applying modern estimation to data from various sources (COMM, gyros, accelerometers, GPS/GNSS, radar, optical, etc.).  Another area, shape deformation analysis in 3-D, offers medical imaging advances plus early notification for earthquakes and infrastructure collapse as well.


For more information see the many blogs and videos on this website.

A Look Back In Time 2023

By James Farrell • 09 May, 2023
A look back in time by James L Farrell, PHD - 2023

2017-2019 IN REVIEW PRE-COVID

11 Apr, 2020
Apologies for little posting lately. Much activity included some with deadlines; this will focus primarily on the few years leading up to Covid.

Activities over the past year

By James Farrell • 30 Aug, 2018
Apologies for little posting lately. Much activity included some with deadlines; this will be limited to the past twelve months. In 2017 my involvement in the annual GNSS+ Conference again included teaching the satnav/inertial integration tutorial sessions with OhioU Prof. Frank vanGraas. Part I and Part II are likewise being offered for Sept 2018. Also...Read More

Inst. of Navigation GNSS Tutorials

28 Jun, 2018
Once again I am privileged to work with Ohio University Prof. Frank vanGraas, in presenting tutorial sessions at the Institute of Navigation’s GNSS-19 conference. In 2019, as in several consecutive previous years, two sessions will cover integrated navigation with Kalman filtering.  Descriptions of the part 1 session and part 2 session are now available online. By way of...Read More

TWO PILLARS OF OUR INDUSTRY’S EXPERTISE

30 Apr, 2018
The Institute of Navigation’s GNSS+ 2018 Conference provides me the privilege of collaborating with two of the industry’s pillars of expertise. Ohio University Professor Frank van Graas and I are offering fundamental and advanced tutorials.  Then on the last day of the conference I’m coauthored with William Woodward, Chairman of SAE Int’l Aerospace Avionics Systems Division and hardware lead...Read More

Opening of Doors Previously Riveted Shut

24 Apr, 2018
A new SAE standard for GPS receivers is a natural complement to a newly receptive posture toward innovation unmistakably expressed at high levels in FAA and Mitre (ICNS 2018).  Techniques introduced over decades by this author (many on this site) can finally become operational. 1980s euphoria over GPS success was understandable but decision-makers, lulled into complacency, defined requirements in adherence...Read More

SAE Standard for GPS Receivers

22 Mar, 2018
At April’s ICNS meeting (Integrated Communications Navigation and Surveillance) as coauthor with Bill Woodward (Chairman, SAE International Aerospace Avionics Systems Division), I’ll present “NEW INTERFACE REQUIREMENTS: IMPLICATIONS for FUTURE“.  By “future” we indicate the initiation of a task to conclude with a SAE standard that will necessitate appearance of separate satellite measurements to be included...Read More

Measurements from GPS and GNSS

16 Jul, 2016
A recent video describes a pair of long-awaited developments that promise dramatic benefits in achievable navigation and tracking performance.  Marked improvements will occur, not only in accuracy and availability; over four decades this topic has arisen in connection with myriad operations, many documented in material cited from other blogs here. 

REASONS for INACTION — and CONSEQUENCES

12 Feb, 2016
For reasons, consider a line from a song in Gilbert-&-Sullivan’s Gondoliers: “When everybody is somebody, then nobody is anybody” — (too many cooks) For consequences, consider this question: Should an intolerable reality remain indefinitely intolerable? While much of the advocacy expressed in my publications and website have focused on tracking and navigation, this tract concentrates...Read More

COLLISION AVOIDANCE: HELP URGENTLY NEEDED

08 Dec, 2015
Let me begin with a quote worth repeating — “Do we really need to wait for a catastrophe before taking action against GNSS vulnerabilities ?” — and follow with an extension of scope beyond. It’s encouraging to see LinkedIn discussions recognizing ADSB limitations that preclude dependable collision avoidance capability – but that recognition needs to be far more widespread....Read More
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