Why Consider Professional-Grade GPS Receivers?
With increasing pressure to accomplish more work for less money, GPS field data collection systems based around inexpensive recreational-grade equipment may initially seem tempting. These products provide features that, at first glance, seem sufficient to do the job with price tags far below professional-grade GPS receivers. Given the large selection of products on the market today, selecting the right receiver that will meet your requirements can be challenging.
When shopping for a GPS unit, users should evaluate receivers against their project and GIS application requirements. There are significant differences between recreational and professional-grade GPS receivers, which are designed and built for different purposes. Recreational units are GPS satellites only and don’t support multiple GNSS constellations like GLONASS and Galileo. They are designed to acquire a location fix quickly without the need for pinpoint accuracy, unlike professional-grade GPS receivers which are designed to achieve both high accuracy and precision on a consistent basis.
When choosing between receivers, users should answer the following questions to be certain the unit will meet their specific needs.
Is five meter accuracy sufficient for your project?
Recreational-grade receivers average around 10 meters of accuracy in autonomous mode. Some units can now utilize a real-time correction source capable of improving accuracy to five meters or a little better.
Is sub-foot or sub-meter accuracy required for your project?
For many GIS users, accuracy requirements are measured in inches and centimeters. In those cases, professional-grade GPS receivers are the only ones capable of achieving that level of consistent accuracy and precision. Please refer to a previous blog entry by Jon Gipson that explains the differences between accuracy and precision in GPS data collection.
Is elevation accuracy important?
Only professional-grade GPS receivers can achieve a high elevation accuracy that is often close to the horizontal accuracy of the unit.
Will you be collecting custom features and attributes associated with location points?
Many mappers have found that custom features and attribute data collection is an important part of their workflows. Professional GPS software applications offer tools that allow for customizable user interfaces and routines to support detailed data collection.
Do you have data quality control options?
Professional-grade GPS receivers and software provide users with the ability to set rules for controlling the minimum level of accuracy for points collected. They also support advanced data collection workflows like establishing vertexes, segmenting line features and working with integrated laser rangefinders for performing offsets and other measurements.
Do you need to integrate data seamlessly with a professional GIS system?
Will you need to convert GPS points to a specific GIS format like an ESRI shapefile or an AutoCAD format? Professional software applications support a variety of advanced export formats including the widely used Google Earth and Microsoft CSV.
Confidence in Data: The Final Differentiator
For GPS users, settling for a receiver that collects data that is less accurate than required can cast doubts over management decisions based on the information coming out of the GIS system. Professional-grade units provide repeatable high accuracy and precise data that instills confidence in geospatial decision making.
Based on price alone, the purchase of recreational GPS units to act as the core of a data collection system can appear to be the obvious answer. However, careful consideration needs to be given to the requirements of the data being collected in the field, the necessary GIS system data requirements and software applications that offer advanced tools for managing the start-to-finish process of collecting and managing GPS field data.
Modern professional GNSS receivers are designed and built with the express requirements of the GIS industry taken into account. Although the professional units are initially more expensive to purchase than their recreational counterparts, the return on investment achieved by using these units will quickly surpass the initial capital investment.
Our Mapping & GIS specialists in the Bay Area, San Diego, Sacramento, and Los Angeles can help you find the right solution for your application today.
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