GPS Standards

GPS Standards

GIS Data Collection Standards:

In implementing a comprehensive GIS, Richland County has begun collecting thematic
data for several departments and applications using global positioning system (GPS)
technologies. For GPS data collection projects within the County, a set of minimum
standards is being followed to assure consistency in resulting products. This document
is a summary of GPS standards used by County personnel.

It should be noted that Richland County has adopted the GPS standards developed
by the North Carolina Geographic Information
Coordinating Council
. There is no similar coordinating body or set of approved
standards for South Carolina. For a complete review of the technology and standard
elements, please refer to the full text
of the NC GPS standard
.

I. Overview

This document establishes the minimum GPS standards to be used by County personnel
involved in mapping activities as well as individuals and groups submitting digital
data to Richland County, South Carolina. Please refer to the NC GPS Standard document for field method guidelines as
well as specific requirements for accuracy and precision. The following addresses
only ground collected data and does not apply to aerial GPS procedures. The standards
apply to current technology and are subject to revision as GPS equipment develops.

II. Standards

GPS Receiver Standards

  • The GPS receiver must be of mapping-grade or better.


  • The GPS receiver must produce and store data in a format compatible with the base
    station data used to perform the differential corrections or have the capability
    to receive real-time corrections from the base station.

GPS Data Collection Standards

Static Collection - We suggest standing at a collection location for 5-10
seconds to evaluate the quality of signal (PDOP and number of satellites) before
gathering points.

Kinematic Mode - Although kinematic collection will acquire points at lower
positional accuracy, we accept line features collected with this method provided
points are collected frequently.

Elevation Mask - The elevation mask should be set to 10 degrees or higher.

Horizontal Datum - NAD 83 (North American Datum 1983)

Spheroid - GRS 1980

Positional Dilution of Precision (PDOP) - Set your receiver to collect points
only when PDOP is less than 6.

Satellites - Set your receiver to collect points only when it has signals
from 4 or more satellites.

Units - Units will be in International Foot.

Coordinate System - Data submitted to Richland County will be in South Carolina
State Plane coordinate system.

Elevation Mode - Use the Height Above Ellipsoid (HAE) as the elevation mode.

Exchange Format - ESRI Shapefile (one file per theme).

Metadata - .TXT file including collectors name, date collected, theme description,
and receiver type.