Field data collection is an important part of any business and mobile data collection is becoming the most favored route. By eliminating non-essential steps from the collection process to data entry, mobile field data collection helps in reducing the time and resources needed to complete the process. What’s more? Real-time data gathered onsite lead to faster and more effective business decisions.
GIS and data collection
Data collection is an integral part of GIS. Typically it accounts for 15–50% of the total cost of a GIS project. The field data related to various map attributes, facilities, assets, and organizational data are digitized and organized on the target GIS system in appropriate layers. GIS data capture is done using either raster data capture or vector data capture technique.
While the raster data capture technique involves capturing of data without physical contact, and is usually done with the help of satellite imaging techniques such as aerial photography, vector data capture techniques include capturing of data through physical surveying methods such as using electronic total stations. Vector data capture technique is the most effective process to have accurate data on GIS.
GNSS for data capture
A popular way of capturing primary vector data is GNSS, which is largely helping organizations in realization of surveys and production of maps.
The use of GNSS techniques in surveying and GIS has revolutionized the way geodetic measurements are made. Not only the results are faster and better, but also widespread use of GNSS technologies is leading to low-cost data acquisition processes. This, in turn, is making the technology more popular for GIS and survey data capture.
In comparison to traditional methods of surveying, GNSS-based surveying reduces the amount of equipment and labor required to capture data. When theodolites were used for determining a new survey position, in case the new and existing survey points were separated by a large distance, the process would involve multiple setups of the theodolite, then multiple angular and distance measurements. This would be a time consuming process. By setting up a DGNSS or RTK base station over an existing survey point and a DGNSS or RTK rover over the new point, surveyors are now able to record the position measurement at the rover.
GNSS based surveying is also yielding excellent results in seismic surveys. GNSS combined with LiDAR is providing the users an exceptional visual representation of field data.
Equipment are evolving
GNSS surveying involves the use of GPS and GNSS signals via a GNSS receiver and antenna to determine the form, boundary, position of objects or points in space relative to other forms, boundaries or points.
With time, the size and functionalities of GNSS receivers have been continuously changing. Moving on from large analog equipment, available in 1970s, we now have GNSS receivers that have been widely expanded to miniaturized platforms, chipsets, microprocessors, Integrated Chips, DSP, FPGA, handheld devices, including integration in most mobile phones. The latest GNSS receivers provide a high-speed Internet connection, enabling the team to access crucial information in the field. Field workers can stay in touch with cellular voice capability. This enables them to relay live updates of the situation back to the office, call the office for their next job, or to request assistance.
The latest in field are the camera enabled GNSS receivers. In these receivers, the integrated camera enables field workers to store a visual record of jobs. We now also have products that take 360-degree panoramic photographs. These images are continuous and precisely positioned. GNSS data is recorded before the panoramic photographs are taken, and position and attitude data is programmed into the cameras, allowing onscreen determination of positions of objects in the photos, or measurements between objects.
One such innovative product is the SP20 handheld GNSS receiver which offers innovative camera-enabled centimeter accuracy. With Android-based ease and versatility it’s the optimal tool for cadastral, construction, or topo surveys; a range of GIS jobs from data collection to inspection and maintenance as well as for non-traditional geospatial professionals. The 5.3’’ screen neatly displays the new workflow using a camera to ensure 2D centimeter accuracy handheld and 3D centimeter accuracy with monopole setup.
Undoubtedly, GNSS receiver is becoming the most valuable tool in the surveyor’s toolbox, and when available with camera, the appeal and performance just exceeds all expectations!