Notes on how to use ArcGis

Data Analysis

• HowToImport3dPointsFromExcelToShapeFile

• HowToImportShapeFileToDb

• HowToCreateSolidPolygon

• HowToCreateTopPlans

Data Gathering Requirements

• ShootingPointsWithTotalStationTips

Documenting Loci

Loci are generally made up of surface layers. When you are working in ArcGIS, you will be dealing with surfaces. Make sure to get clear boundary surfaces for top and bottom of all loci that you intend to show in the 3D representation. For shooting point tips see ShootingPointsWithTotalStationTips. Make sure to document these points as being used for surfaces as apposed to top plans or objects. When importing the points in the evening make sure this designation tranfers into the excel sheet that will be imported into the database.

If the layer wanders horizontally as you dig down, make sure to get edge measurements of the loci for each shift (probably will be each day). You do not need to get internal points unless:

• You are opening or closing a loci
• You need a mesurement for an object
• You need it for a top plan

Documenting Top Plans

THIS SECTION NEEDS TO BE WRITTEN: I.e. for the time being we need to use the manuals to determine how we identify individual top plan elements.

Earlier experiements

This rest of this page deals with how we generally used ArcGis in Archaeology. We also document the following topics:

• Three different implementations Vector Models (also called FeatureClasses) in ArcGIS (for now we'll assume that these are differently formatted files - not separate models)

  • Coverages (file based model)

  • ShapeFiles (file based model)

  • GeoDatabases.

• Raster Models: Images or Grids. Of these two, images are well understood. Grids can be made from images, but in essence they allow attributes to be stored for each grid square in the picture.

  TIN stands for TriangulatedIrregularNetworks.

If you are installing this on a computer that you want to use with our project see ArcInfoInstallationNotes

Initial process developed to use points from a Garmin GPS

To start with you will be working in ArcMap.

Importing GPS Data

First we used a USB GPSMap 76 CS Garmin to find points. This was preliminary work while we were waiting to get the survey equipment.

To import the points we use the DNRGarmin add-in for ArcGIS. It works beautifully! Import the track as points. This will create a ShapeFile.

Use the 3dAnalystExtension to make a Surface TIN out of the shape file. Now you have the surface data you need to drape the image over.

Rectifying the Image

Assuming you have an image, you need to import and add it to the project. (By the way you may want to look at the ArcCatalog for more info on this). Once you have the image imported, use the GeoReferencing toolbar to Move the image in place by repeatedly using

1. Fit to Display
2. Scale
3. Shift
4. Rotate

Once you are about there, you can use the add control points tool to scale the image and move it into place. See the RectifyingImage.pdf tutorial for extended directions.

Finally rectify the image in the GeoReferencing toolbar. This will create another image that has spatial data attached to it.

Creating the 3D image

In ArcScene open add the TIN created above and the Image created in the previous section. Right click on the image and select properties. Select the Base Heights tab and click the radio button to Obtain heights for layer from surface. Select the TIN file if it isn't already selected and click OK. Uncheck the TIN layer to just see the picture.

IF the heights aren't very well defined you can exaggerate them by right clicking on "Scene Layers", properties, General Tab, Vertical exageration set to 2 or whatever.