GPS and GIS Training and Support Services:

GPS Mapping Experience

PVTS has provided consultation, training and service in the area of Satellite Based Land Surveying to numerous firms and individuals.

Below are some examples of what we have delivered to clients:

I.) 10-15 GPS control projects ranging in size from 500 acres to 7500+ acres. These projects were principally bringing HPGN or OPUS derived control on to large area remote sites in Napa, Sonoma and Mendocino counties for aerial imagery, boundary surveys, route surveys and topographic surveys.

II.) 25-30 GPS control projects under 500 acres. These projects were principally bringing HPGN or OPUS derived control on to nearby or remote sites in Napa, Sonoma and Mendocino counties for aerial imagery, boundary surveys, route surveys and topographic surveys.

III.) Trancas Street Napa River Bridge: Vertical Control Project – Use of long occupation GPS to re-establish vertical control at Bridge site.

IV.) Township and Sections Boundary Retracement Survey: Use of GPS to reconstruct a fraudulently surveyed township in eastern Napa County. PLSS surveys of fifteen to eighteen of the thirty-six sections of T8N, R4W, MDM, were tied using GPS in order to retrace boundaries relating to four large adjoining ranches in Napa County.

 V.) Kirkland Ranch Control Survey: Use of long occupation RTK GPS to establish project control across 7500 acres with gross elevation changes of roughly 1500 feet. The survey control data were divided into 5 elevation regions. Each control region was individually scaled to minimize the large potential grid-to-ground conversion errors which would occur across long baseline distances with elevation changes at the extremes.

 VI.) Farmer’s Lane Freeway Extension, Santa Rosa, California -- GPS control survey - unification of five independent historical control surveys to CSP coordinate system with ties to HPGN/OPUS.

 VII.) Pepperwood Grove Ridgeline Control Project: Santa Rosa, California -- Use of RTK GPS for Route Survey of Road Centerline Control. GPS control survey for the unification of three independent historical control surveys to CSP coordinate system with ties to HPGN/OPUS.

 VIII.) Township and Sections Boundary Retracement Survey: Use of GPS to retrace approximately 1500 acres of PLSS surveys in Lake County as part of a boundary survey for adjoining lots seven and one of sections six and seven respectively in T12N, R7W, MDM. The final survey data were expressed in California State Plane, Zone 2 coordinates on NAD83 Epoch 2002.00.

IX.) Kingsbury Line (orig. 1877) Retracement – Napa-Sonoma County Line: Use of Static GPS methods to control a 52 mile boundary retracement survey between Napa and Sonoma Counties from Mt. St. Helena to the mouth of Huichica Creek at San Pablo Bay. Cooperative participation between four (4) survey companies contracted to set GPS control for terrestrial monument infill at 1 mile intervals. The final survey data were expressed in California State Plane, Zone 2 coordinates on NAD83 Epoch 2007.00.

X.) Mobile LiDAR Scanning Control Development: Use of GNSS and terrestrial survey methods to develop control and calibration courses for static and kinematic (mobile) LiDAR scanning ground control. Application of GNSS control survey methods, differential leveling and terrestrial survey methods to establish a ground control reference network for vehicle mounted high definition scanning calibration purposes. Consultation and basic training to 3^rd party developer for major equipment manufacturer (name withheld due to non-disclosure agreement).