All resources in Geomatics, GNSS & GIS

Two Right Feet? Understanding the Difference Between U.S. Survey Feet and International Survey Feet

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This video explains the difference between the U.S. survey foot (sFT) and the international survey foot (iFT) and the importance of this distinction when working with map projections. It will be helpful to surveyors, planners and anyone who needs to convert map coordinates from meters to feet. This resource is hosted on COMET's YouTube Channel.

Material Type: Module

Author: COMET

An Introduction to Geodetic Datums

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This series of short videos, produced in collaboration between NOAA’s National Geodetic Survey and The COMET Program, provides an introduction to geodetic datums for anyone who uses mapping products or other geo-spatial tools. 1. What are Geodetic Datums? (4:36) In this video we explain the basic concepts behind geodetic datums, where they are used, and why it is important to know about and use the correct datums. 2. How Were Geodetic Datums Established? (3:12) In this video, we explore the history of geodetic datums in the United States, and how they were established at a national level to assure consistency across mapping applications. 3. What Is the Status of Today's Geodetic Datums? (4:49) Here we examine the use of the current primary geodetic datums used in the US, NAD 83 and NAVD 88, the challenges in maintaining these datums, and the inconsistencies that arise when they are used together with the latest satellite-based mapping technologies. 4. What's Next for Geodetic Datums? (4:41) Finally, we look at current plans for developing more accurate horizontal and vertical datums, (referred to respectively as geometric and geopotential datums), the expected benefits and impacts, and the importance of preparing now to adopt these new datums. This resource is hosted on COMET's YouTube Channel.

Material Type: Module

Author: COMET

Geospatial Infrastructure for Coastal Communities: Informing Adaptation to Sea Level Rise

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Aimed at community planners, emergency managers, and other coastal zone decision-makers this video will explain how using geospatial information already available through NOAA, combined with strategic local investments in infrastructure can provide communities with the data needed to confidently plan for future sea-level changes. This resource is hosted on COMET's YouTube Channel.

Material Type: Module

Author: COMET

Geo-information Technology for Crisis Management

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Geo-information has proven to be extremely helpful in many aspects of risk and disaster management: locational and situational awareness, monitoring of hazards, damage detection, sharing of information, defining vulnerability areas, etc. This course aims to provide knowledge on risk and disaster management activities, demonstrate use of geo-information technologies in emergency response, outline current challenges and motivate young geo-specialist to seek for advanced solutions. The course is organised as lectures and practicals. The practicals will be in the form of group assignments. Some excursions and guest lectures will be organised as well.

Material Type: Lecture, Lecture Notes, Reading, Syllabus

Author: Dr. ir. S. Zlatanova

Geospatial System Analysis and Design

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Geospatial System Analysis and Design surveys the process of GIS design through critical reading/writing and collaborative discussion. Key topics in the course outline the broad range of current GIS systems, how they are designed and evaluated, and how emerging technologies may impact their design and implementation in the near future. In particular, students will develop a term-long project where they propose a realistic problem scenario that requires the skills and understanding required to effectively complete a geospatial system specification, design, and implementation. Students completing this course are able to develop a comprehensive system design plan that takes into account current technologies as well as emerging technology trends.

Material Type: Full Course

Authors: Alan MacEachren, Anthony Robinson, George Chaplin

Satellite Navigation

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Global Satellite Navigation Systems (GNSS), such as GPS, have revolutionized positioning and navigation. Currently, four such systems are operational or under development. They are the American GPS, the Russian Glonass, the European Galileo, and the Chinese Beidou-Compass. This course will address: (1) the technical principles of Global Navigation Satellite Systems (GNSS), (2) the methods to improve the accuracy of standard positioning services down to the millimeter accuracy level and the integrity of the systems, and (3) the various applications for positioning, navigation, geomatics, earth sciences, atmospheric research and space missions. The course will first address the space segment, user and control segment, signal structure, satellite and receiver clocks, timing, computation of satellite positions, broadcast and precise ephemeris. It will also cover propagation error sources such as atmospheric effects and multipath. The second part of the course covers autonomous positioning for car navigation, aviation, and location based services (LBS). This part includes the integrity of GNSS systems provided for instance by Space Based Augmentation Systems (e.g. WAAS, EGNOS) and Receiver Autonomous Integrity Monitoring (RAIM). It will also cover parameter estimation in dynamic systems: recursive least-squares estimation, Kalman filter (time update, measurement update), innovation, linearization and Extended Kalman filter. The third part of the course covers precise relative GPS positioning with two or more receivers, static and kinematic, for high-precision applications. Permanent GPS networks and the International GNSS Service (IGS) will be discussed as well. In the last part of the course there will be two tracks (students only need to do one): (1) geomatics track: RTK services, LBS, surveying and mapping, civil engineering applications (2) space track: space based GNSS for navigation, control and guidance of space missions, formation flying, attitude determination The final lecture will be on (scientific) applications of GNSS.

Material Type: Assessment, Homework/Assignment, Lecture Notes, Reading

Author: A.A. Verhagen

Best Practices for Minimizing Errors during GNSS Data Collection

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Aimed at surveyors and GIS professionals who use geodetic-quality GNSS equipment to determine positions for land planning, coastal monitoring and other purposes, this video covers best practices for reducing errors in the areas of: 1. location and environment, 2. equipment setup and 3. observation times and accuracy checks. This resource is hosted on COMET's YouTube Channel.

Material Type: Module

Author: COMET

GPS and GNSS

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Today GPS is critical to positioning, navigation, and timing. The smooth functioning of financial transactions, air traffic, ATMs, cell phones and modern life in general around the world depend on GPS. This very criticality requires continuous modernization. The oldest satellites in the current constellation were launched in the 1990s. If you imagine using a computer of that vintage today, it is not surprising that the system is being substantially updated. Global Positioning System (GPS) is now a part of a growing international con?text-the Global Navigation Satellite System, GNSS. This course dives into how GPS and other GNSS systems are designed, how they operate, and the impacts they have on spatial analysis and spatially-enabled systems.

Material Type: Full Course

Author: Jan Van Sickle

Acoustic Remote Sensing and Sea Floor Mapping

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The course treats the following topics: - Relevant physical oceanography - Elements of marine geology (seafloor topography, acoustical properties of sediments and rocks) - Underwater sound propagation (ray acoustics, ocean noise) - Interaction of sound with the seafloor (reflection, scattering) - Principles of sonar (beamforming) - Underwater acoustic mapping systems (single beam echo sounding, multi-beam echo sounding, sidescan sonar) - Data analysis (refraction corrections, digital terrain modelling) - Applications (hydrographic survey planning and navigation, coastal engineering) - Current and future developments.

Material Type: Homework/Assignment, Lecture Notes, Reading

Author: dr.ir. M. Snellen

Precision and Accuracy in Geodetic Surveying

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This brief video focuses on the importance of both precision and accuracy in geodetic surveying and the difference between them. Produced in collaboration between NOAA’s National Geodetic Survey and The COMET Program, this video is aimed at surveying professionals, planners, policy-makers and others who use mapping products. The video emphasizes that the accuracy of survey measurements should always be verified by relating measurements to a known reference system such as the National Spatial Reference System in the United States. This resource is hosted on COMET's YouTube Channel.

Material Type: Module

Author: COMET