Get It Surveyed!
Steve Slusarenko, Chief Innovation Officer - September 4, 2019
We were looking at a map of North American petroleum pipelines yesterday and it depicted a massive intricately woven tapestry of gathering and transmission pipelines. We were astounded at the sheer number of pipelines and the complexity of the network. Of course the majority of them are buried and therefore out of sight, so unless you are looking at a map of them such as we were, you would never know that there are so many.
The first of these pipelines were built over 100 years ago. The majority of the pipelines that we see in the map today are over 50 years old and also predate the use of Geographic Information Systems (GIS). These lines were placed and their locations mapped using survey equipment and the survey datum prevalent in the day was NAD 27. This survey datum is still used today and, in fact, the map we were viewing today used NAD 27 as the reference datum. Considering that the survey equipment used at the time to establish this datum was replaced in later years by more precise equipment, the datum was refined in 1983 to establish the new NAD 83 datum. In Texas, for example, the difference in the datum produces a horizontal shift of 22 meters at the eastern border to about 52 meters at the western border. By itself, this change in datum introduces some errors, but as long as we know which datum and geoid were used, we can do a transformation to ensure that we are positionally correct. Of a more serious nature and one where we cannot do a simple transformation to correct the data is related to how the GIS data was created.
Even as late as the 1980’s, Geographic Information Systems were still in their infancy and almost all records that were created in GIS systems were manually entered based on historical information from plans and paper maps. Even today, there are many firms that still interpret what they are provided on paper and manually enter the features by “eyeballing” this into the corporate GIS. The result anywhere from fairly minor inaccuracies of several feet to gross errors of hundreds of feet or more. All too often these errors, even the gross ones, go unnoticed for years. These geospatial errors continue to exist for two reasons; the continued use of paper resulting in manual data entry into GIS applications, and the inability of personnel in the field to visualize the GIS information so that they can verify the accuracy of the GIS data. Newly developed data collection tools can provide the necessary visualization and communication channel between the GIS Department and Field Operations to eliminate these errors. At some State DOT’s, in recognition of the source and accuracy of the records, they define GIS as an acronym for “Get It Surveyed”. Creating accurate records is precisely what State Department of Transportation professionals and professionals in other industries are working on.
At ProStar we are working with industry to make our world a safer place to live and work in. We do this by providing solutions to allow our clients to precisely record and easily visualize the location of infrastructure that we otherwise cannot see. We do this by integrating cloud, GPS, EM Locate tool, and Laser Range Finder technologies into easy to use software applications that enable users to capture, register, and share the nature and exact location of buried assets.
ProStar has developed two closely integrated and complementary products, a desktop application called Transparent Earth® that is offered on the cloud and used to manage and display the data, and PointMan®, a mobile data collection and display application. Transparent Earth provides the ability to communicate and share data in real time with internal corporate and external business systems such as GIS and CAD applications in addition to being fully integrated with our PointMan mobile data collection app. Any data imported by Transparent Earth can be displayed on the map, searched for, sorted, filtered, and shared. PointMan is also able to export data to external systems, and it is capable of working completely offline and syncing when a cellular or WiFi network is available. PointMan can be run on any Android or iOS device and can be coupled via Bluetooth to a GPS receiver to allow the user to capture and record Survey Grade data in real time.
When collecting data to support Subsurface Utility Engineering activities, applying the ASCE 38-02 Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data or CSA S-250-11 Mapping of Underground Utility Infrastructure standards to the collected data and denoting the ASCE Quality Level and/or CSA Accuracy Level designations as appropriate, these records must be signed off by a registered professional giving the design engineer a clear picture of the data quality. When the design activity is completed and the utility quality levels have been stripped from the data to meet legal and insurance requirements, PointMan retains the precision, pedigree, and provenance to assure stakeholders that GIS means “Got It Surveyed!”