Joseph V.R. Paiva PhD, PS, PE

Joe Paiva brings more than three decades of experience to GeoLearn. From his start as a university instructor, Joe has been committed to education and bringing course material to professionals and technicians in various settings since 1975. His broad experience in the geospatial field includes teaching surveying as assistant professor at the University of Missouri-Columbia; developing and instructing online courses as adjunct faculty at Missouri University of Science and Technology; designing professional and technician continuing education; engineering and geomatics practice; product development; and business management. Past posts include vice president at Sokkia Technology, Inc., and Trimble; COO at Gatewing; and independent consultant to a large selection of companies engaged in geomatics product development and sales. Joe writes prolifically on general interest and technical topics for leading industry publications, including POB Magazine, GeoDataPoint, and The Empire State Surveyor, and is a past contributor to Civil Engineering News. He is highly sought-after as a speaker and adviser for professional societies. Joe received B.S., M.S., and Ph.D. degrees in civil engineering from the University of Missouri.

Joe is a director and owner of GeoLearn. Joe has broad experience in the areas of post-secondary education, professional and technician continuing education, engineering and geomatics (land surveying and mapping) practice, product development and business management.

Joe's Courses

Errors Analysis in Surveying – Part I

Why errors should be of considerable attention in the life of a surveyors activities are first presented before moving to the topics to be covered in the series. We begin with a discussion what errors are, where they come from (sources) and how they are classified into types. Mistakes or blunders, which are not errors, are also discussed. Precision and accuracy are covered, using the bull’s-eye analogy. The discussion then moves on to a discussion of residuals as a way of modeling errors. Concepts such as the mean, standard deviation and the histogram are presented.  How uncertainty and probably are presented in surveying measurements are discussed, with concluding discussion on how standard deviation is calculated and how it can be used to analyze data, and when it can be used as an indicator accuracy, not just precision.

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State Plane Coordinates I

This first course in a series on this topic introduces the idea of state plane coordinates, gives some of the background about why and how it was developed in the U.S. by the then Coast and Geodetic Survey. The concepts covered include the idea of developed surfaces (cylinder and cone), and how points on the earth are projected to these surfaces that are then laid out as two-dimensional grids. The variation in how the projections work when inside the lines of true scale, when the surface of the cylinder and cone are below the surface of the ellipsoid, and when outside, near the edges of the projections, above the surface of the ellipsoid. This is a good course for someone wishing to understand some basics about the system qualitatively, but who doesn’t intend to move on the subsequent courses in this series.

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State Plane Coordinates II

This second course on the series on State Plane Coordinate Systems covers just a bit of material from the previous course, reviewing the idea of projections and how they work in the case of the Transverse Mercator and Lambert Conformal systems. The course then moves on to discuss how measurements on the topographic surface of the earth are first reduced to sea level (the geodetic distance), before projecting them onto the developable surface appropriate for each type of system. How the distortions in east-west lines and north-south lines once they are projected to the grid are discussed. Then, the 1983 system’s overall points are covered, where necessary, contrasting them with those of the 1927 system. How the 1983 system deals with shapes of states that require use of more than one projection are briefly discussed. Also discussed is the importance of understanding which system of linear units (meters, feet or U.S. Survey feet) has been legislatively adopted, and making the appropriate conversions. When state plane coordinate system values are used, even the 2 PPM difference between the International foot and the U.S. Survey foot is considerable. The course again covers the matter of distortion for each type of projection.

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State Plane Coordinates III

This third course on the series on State Plane Coordinate Systems characterizes the types of distortions that occur with the Transverse Mercator and Lambert Conformal systems. The concept of “scale great than true,” “…less than true,” and “true” is discussed. The concept of the mapping angle is presented and demonstrated qualitatively for both types of projection systems. Typical SPCS constants for a selected number of zones for Transverse Mercator types and Lambert Mercator are shown, using them to reinforce the concept of the Central Meridian. The concept of the geoid is briefly reviewed before proceeding through the computational processes for reducing a ground distance to its geodetic equivalent using the sea level factor and then, using the scale factor to is grid distance equivalent. The process of computing the mapping angles for both types of projections is then covered, concluding with a discussion of how to apply them.

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Geomatics in a UAV World: an Introduction

This is an overview of how UAVs might be integrated into geomatics organizations. It begins with a description of types of UAVs (fixed wing and rotorcraft), and covers some of the important operational details that must be covered when planning a business or a UAV purchase. Drivers for and against UAV use are presented. The topic of photography done with a UAV is covered; the concepts behind the processing, which is different from conventional aerial photogrammetry; types of data products that can be created such as orthomosaics, digital surface models and point clouds. Some example images and products are presented, and empirical accuracy results that have recently been reported for UAV photogrammetry are discussed. The next phase of the course involves a discussion of new and existing aerial applications, sensor improvements that can be expected, and a brief overview of the regulatory environment imposed by civil aviation authorities. In the U.S. some of the expected changes in regulations that the presenter believes will be introduced by the FAA in 2015 and later is covered. The course concludes with what types of research may be done for organizations considering integrating UAV operations.

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The Geospatial World of UAS

This course begins with a discussion of how unmanned airborne systems (UASs), can be a potential game changer in geospatial applications. Types of UAS are briefly covered, including methods of controlling their flights. Types of factors that must be considered before deciding to use UASs to solve a geospatial are covered with a presentation of some of the drivers for and against UAS use. New and future applications are discussed in some detail, together with some of the potential new sensors possible beyond RGB cameras. Operational issues that involve organizational fitness, planning and the process of operating an aircraft are covered. As UAS photogrammetry is an important aspect of using UAS in geospatial applications, how it works is explained, concluding with some empirical accuracy assessments and examples of imagery and data products.

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UAS Photogrammetry

In this course the concepts of close-range photogrammetry and vision software are introduced as they used in UAS. The subject of calibration is discussed. We begin with a discussion of camera features that are critical to UAS operation. The differences between “conventional” aerial photogrammetry and UAS photogrammetry is covered. The workflow in which UAS imagery is used to create an automatic aerial triangulation process (AAT) that leads to a bundle block adjustment (BBA) is then presented. The process of generating feature or match points in overlapping images from 75% or more overlapping imagery is outlined. These points are matched up at the rate of hundreds or even thousands of points per image. Using least squares techniques, camera position, which is measured in flight to the level of meters, and pitch, roll and yaw, measured in the 1° to 2° range are then refined to levels of centimeters and arc-seconds. The prime purpose of the on-board measurements is to provide an initial estimation for the camera position and orientation values. This calculation also generates the interior orientation of the camera (calibration). The course concludes with some operational examples and examples of projects and data products that can be accomplished.

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UAS Technology: Operational Implications

The course starts with a brief discussion of forces on an aircraft in flight and other basic principles of aerodynamics. Concepts such as the three axes of motion and rotor and fixed wing flight are discussed.  Using actual aircraft or full size models in the studio, “guided tours” of fixed wing and rotor aircraft are covered. The tour includes coverage of all the instrumentation to keep the aircraft in the air as well as to control imagers on board. Out-of-normal flight situations are discussed together with the fail safes that most manufacturers have implemented. Some of the factors to be considered when deciding which type of UAS to use are covered. This includes characteristics in the proposed mission area as well as those of the aircraft.

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