Goal

GPS data from last weekend's field trip need to be brought into a GIS and used to edit/modify two existing map; a Mason City Park map and a geologic map of the Lansford Ranch marble occurrence.

Procedure:

The general procedure for lab this week involves the following steps:

1. Clean the field data of spurious GPS point and vertices.  Edit the Lansford Ranch point file attribute table, if necessary, so that strikes/trends and dips/plunges are correct;
2. Select lines, points and polygons from the class dataset to use for your maps or to modify existing rock unit contacts;
3. Convert line features to polygons where necessary and attribute the polygons;
4. Using layer files, symbolize the new data to make a maps.

9.1 Getting Started

1. Download the Lab_9_data_field_trip folder to your network storage space.  This folder contains subfolders for the city park and the Lansford Ranch.  The City Park folder is very large because it contains an 0.5 Gb orthophoto.  If you are low on storage space do not download the whole folder; the lab can be done without the photo.
     
2. Open the Mason_Park map document to find the download data from Saturday.  Data are displayed below in Fig. 1.

Figure 1: GPS points lines and polygons collected at Mason City Park.

9.2 Selecting, Cleaning and Merging Point, Line and Polygon files: Mason City Park data

1. Mason City Park first... Weed the point line and polygon data of duplicate features by editing the map and attribute tables.  The goals is to use as much of the data as possible to construct an attractive park map that shows as many of the mapped features as possible.
   
2. Construct or edit polygons and lines as required to correct any discrepancies between the photo and the digitized features.
   
   
3. Find an Austin city park map on the web that is worthy of emulating (there are many poor ones) and use it as a model to symbolize and label the Mason City Park map.  Do so using no more than 4 colors.
   
   
4. Complete and turn in a Layout of your Mason City park map.

    

9.3 Lansford Ranch Data

1. Open the Lansford ranch map document and use the existing layer files in the Lab_09_data folder to symbolize the point and line features.
   
   
2. As above, weed the point and line data of spurious and/or duplicate features.
   
   
3. Edit the existing polygons or create new polygons (with attributes) to show newly mapped contacts.
   
   
4. Symbolize and layout out the new data in a map layout showing only the part of the ranch encompassed by the new data.  Use labels where necessary.  Data labels that are too close together (e.g. dip labels for measurements) should be converted to Annotations and placed by hand.
   
   
5. Turn in a completed map.

M. Helper, 2011