Categories
Powered by:
- GigaCart.com shopping cart software. Web design and e-commerce solutions.
Survey
Articles
Innovation: Brainy Positioning
Primarily developed for computing applications, such as pattern recognition, neural networks have been adapted for use in several fields of science, including geodesy. Those adaptations are needed because usually the situations and problems encountered in computer science are different from those in other fields. Geodesy is no exception.
2007-09-01
Surveying the Market
GPS products sold in the survey and construction sector range from $1,000 to $125,000, furnishing high gross margins. We explore the business of this industry segment, its key players, and their relationships with providers and vendors.
2007-07-01
Innovation: Photogrammetry for Mobile Mapping
While photogrammetry is often used as a mapping tool on its own, GPS can aid the technique by supplying accurate coordinates for digital cameras. In turn, photogrammetry can come to the aid of a GPS/INS positioning system by bridging gaps in GPS/INS positions, which frequently occur in urban environments.
2007-03-01
Innovation: Stochastic Models for GPS Positioning...
When processing GPS data, we should not only try to model the deterministic part of the measurements; we should also try to account for their stochastic behavior, which is possible through use of the covariance matrix. Here, the authors present an empirical approach for building the covariance matrix of observations, with the ultimate goal to improve the quality of GPS data processing.
2007-02-01
GNSS Accuracy: Lies, Damn Lies, and Statistics
This update to a seminal article first published here in 1998 explains how statistical methods can create many different position accuracy measures. As the driving forces of positioning and navigation change from survey and precision guidance to location-based services, E911, and so on, some accuracy measures have fallen out of common usage, while others have blossomed. The analysis changes further when the constellation expands to ombinations of GPS, SBAS, Galileo, and GLONASS. Software scripts, provided online, help bridge the gap between theory and reality.
2007-01-01
Innovation: Any Questions? The International GNSS...
The IGS was established in 1994 in order to provide the highest quality GNSS data and products in support of Earth science research, multidisciplinary applications, and education. It was and is still the aim of the IGS to advance scientific understanding of the Earth system components and their interactions, as well as to facilitate other applications benefiting society.
2007-01-01
On-Grid Goal
Already adopted by many countries, real-time networks (RTNs) can be a boon to the public and private sectors. In the U.S., the On-Grid initiative seeks to bring together local and regional RTN developers to pool resources so that high-precision real-time GNSS networks can benefit the surveying, scientific, and communication sectors, among many others.
2006-10-01
Innovation: Phase Wind-Up Analysis
A circularly polarized antenna's phase depends directly on the antenna's orientation with respect to the signal source. As a result, the observed carrier phase depends on the relative orientation of the transmitting and receiving antennas as well as the direction of the line of sight between them. Changing the receiver antenna orientation changes the reference direction and thus the measured phase.
2006-09-01
GPS Buoys Nautical Measurements
Global Satellite Based Augmentation Systems (GSBAS) technology has presented us with an opportunity to greatly simplify the gathering of shore data used by the U.S. Navy and other mariners.
2006-05-02
Drive-By DTM
A data teletransmission system for quick and efficient creation of digital terrain models (DTMs) forms the backbone of experimental work in the transmission of differential GPS and real-time kinematic (RTK) corrections. A roving vehicle carries the system and collects data for a precise DTM.
2006-04-01
Guided to Gather — Toy Plane...
GPS/INS and infrared optical sensors propel USGS's transformation of a remote-controlled one-quarter–scale recreational aircraft into a low-cost unmanned aerial vehicle designed for environmental particulate collection.
2006-02-01
Time-Invariant Sea-Floor Depths
A GPS survey combined with acoustic soundings can determine highly accurate sea-floor depths. Using the ellipsoid as the zero-reference surface then allows navigators, while underway, to determine both keel and overhead obstruction clearance independent of the stage of the tide and the draft of the ship and freeboard.
2005-09-01
LiDAR on the Level in Afghanistan
Concerns about airspace security in Afghanistan literally brought a LiDAR-based survey operation down to the ground.
2005-07-01
Precise Rail Track Surveying
Describes a multisensor measurement system incorporating real-time kinematic (RTK) GPS, and its use to survey sections of railroad track in the United Kingdom.
2004-05-01
Mine Eyes
A prototype system tells heavy equipment operators the location of nearby vehicles and obstacles, and warns them when they get too close.
2002-07-01
