Carolina NorthGPS Mapping of Bike Trails

Team B2

(Becky and Jun)

The Project Process

Pre-Survey Site Visit Creation of Data Dictionary Data Collection Data Processing and Differential Correction Map Creation Using ArcGIS Suggestions for Future Data Collection

Data Collection

“Neverland” section 6 (shown in red)

April 4: line feature data only (about ¾ of trail from E to W)

April 9: rest of trail, plus point features

Data Collection Results

April 4 trail– 568 positions– PDOP of 2.9 to 5.8– Time coverage

4:05:55pm to 4:22:25pm– 4 to 6 satellites

April 9 trail– 194 positions (one way)– PDOP of 2.4 to 6.9– Time coverage

4:15:38pm to 4:19:37pm– 4 to 6 satellites

Data Processing (raw .ssf data files)

April 4: April 9:

Differential Correction

Data was corrected using Hillsborough CORS station reference data--Estimated accuracies for 1st trail (594 corrected positions) are as follows:

Range Percentage ---------- ---------- 0-15cm - 15-30cm - 30-50cm - 0.5-1m 0.8% 1-2m 61.1% 2-5m 37.7% >5m 0.3%

Differential Correction (cont.)

April 9th file results: Range Percentage

---------- ---------- 0-15cm - 15-30cm - 30-50cm - 0.5-1m 1.5% 1-2m 87.6% 2-5m 10.7% >5m 0.2%

Map Creation

Air photo from Joe (Orange County) Export of feature data from PFOffice to layers

in ArcMap All layers projected to NC State Plane

(1983 survey feet) coordinate system

Suggestions for future data collection

Too many “Dangerous Locations”? Pictures would be more effective if tied to

nodes (as Data Dictionary option?) Use QuickPlan with Almanac to ensure good

satellite coverage Collect in winter to avoid heaviest canopy Descriptive folder names/good management

(once files are downloaded)