# Core Articles

## Coaching Robots

Continuous surveying (to support smart cities, infrastructure, geodesign, and construction) is opening expanded—but unconventional—roles for surveyors and geospatial practitioners. A member of your field crew that’s a bipedal, survey-rod-carrying robot may be in the distant future, but the work of field data collection has already been affected by robotics, namely in the form of process...

## Fundamentals of Geodesy

Part 1: An Introduction Editor’s note: With this article we start an overview of GeoLearn courses offered by Dave Doyle, former chief geodetic surveyor for the National Geodetic Survey and geodesy editor of xyHt.  GeoLearn (geo-learn.com) is an online education business helping professionals reach mandatory continuing education requirements and sort through everyday work issues. Dave’s...

## Feature: A New Datum

Finally: the rationale for a new geometric geodetic reference frame to replace the North American Datum of 1983. In 2008, the NGS released the publication of a ten-year operating plan that, among other things, called for efforts to replace NAD 83 and NAVD 88, the official horizontal and vertical geodetic datums of the United States.  (Note...

## Where Theory Meets Practice: Geodetic Observations: Part 1

Since the inception of GPS in the 1980s, surveyors have been presented with GPS baseline reduction results that list both geodetic azimuths and distances for the baseline vectors. In Part I of this article, I present the difference between the normal to the geoid and ellipsoid, which is known as deflection of the vertical, and...

## xyHt: What Does It Mean?

Why did we pick an obscure geodetic expression as the name of our magazine? It’s not all that obscure—it represents a foundational element requisite to nearly all human endeavor. It touches your life explicitly and in the abstract. All of the ways that humans have measured and gauged their world, each of the conventions they...

## What is xyHt?

Stand in the place where you live Now face North Think about direction Wonder why you haven’t before “Stand” – R.E.M. Why an obscure geodetic expression? It’s not all that obscure—it represents a foundational element requisite to nearly all human endeavor. It touches your life explicitly and in the abstract. All of the ways that...