Eureka County was looking to update aerial mapping in most of the Townsite of Eureka as well as acquire mapping in the populated areas of the county that had previously unmapped. The goal was to be able to utilize the mapping for planning and design of future projects as well as to provide the Assessor’s Office with aerial imagery that could be utilized for G.I.S. purposes. Previous mapping in the town had been based upon a user defined coordinate system. The project objective was to establish horizontal control relative to the Nevada State Plane Coordinate System and the vertical control relative to the North American Vertical Datum of 1988 (NAVD 88) to match recently revised FEMA flood insurance rate maps.
Lumos worked with the photogrammetry subconsultant to provide the mapping in the form of a 1″=40′ scale map with 1′ contour interval mapping standard for the Townsite, a 1″=100′ scale map with 2′ contour interval mapping standard for the area south of the Townsite that was to be used to design a water collection system; capturing water from the natural springs south of town. Both of these areas included 0.2′ pixel color digital orthophotos. Lumos provided mapping of the populated areas of Devils Gate, Crescent Valley, and Beowawe in the form of 0.2′ pixel color digital orthophotos.
Since Lumos received notice to proceed in mid fall it was critical that the ground control was sent and to conduct the aerial photography as quickly as possible to avoid snow cover that would of set the project back until spring. Lumos sent multiple crews to the different areas to set paneling material, to get all the areas flown before the first snow fall, in and to save money by minimizing flight mobilizations. Lumos began establishing the control using a combination of Real Time Kinematic and Post Processed GPS methods. Being in such remote areas, it was difficult to find NGS benchmarks and reference points. Post processing our results through the NGS On-Line Positioning User Service (OPUS), enabled us to verify control. Lumoswere able to establish and densify control in all the populated areas of the County referencing the requiredNevada State Plane Coordinate System and NAVD 88 datums.