By Members of ISAAKiel

Moritz Mennenga (Lower Saxony Institute for Historical Coastal Research Wilhelmshaven)

Kay Schmütz (Graduate School - Human Developent in Landscapes / CAU Kiel)

Christoph Rinne (Institute for Pre- and Protohistoric Archaeology / CAU Kiel)

How to use the profileAAR-Plugin

ProfileAAR is a plugin to transform measured photogrammetry points to allow equalization of sections in GIS.

The points are rotated and shifted according to different specifications (see below),

the determination of the rotation parameters is based on a linear regression.

1. Input data

You require a shapefile with points. Several sections can be processed at the same time

The shapefile must have at least the following attributes

• the z-value [float/double/real]
• the label of the section (e.g. number of the section [text or number])
• the view direction (defined by the position of the observer related to the section (view from ...) as N, E, S or W [text])
• the used Points (points that are used to determine the slope of the regression [0/1])


If a section is NE - SW orientated it doesn't matter if you choose E or S.

Example for an attribute list

2. Options

First, the layer and then the associated attributes in the dropdown menus must be selected. z coord, the pr number, the use and the view column boxes.

In this case use means whether the point will be used to calculate the rotation angle (coloumn with '1'). If there is an outlier in the data, mark it with a '0'.

Please select the matching attributes.

In the next two boxes, you have to choose:

In the Method box:

• 1.: Projected. The section will be projected on a vertical projection pane. This is like a drawing in the field.
• 2.: Surface. The section will be projected on a pane, that is parallel to the section. This is like drawing the surface of the section.


Sideview of a section (0). The result after choosing projected (1) or surface (2).

In the Direction box:

• 1.: Original. The points will be parallel to the section.
• 2.: Horizontal. The points will be parallel to the x-axis.
• 3.: original height. Same as horizontal but the section will be at x = 0 and y is the measured height. This allows an export with a coordinate frame.

Before using the third option original height always check whether the given coordinate system is still constant in scale at the origin



View on a section(0). The result after choosing original (1) or horizontal (2).

Export elevation points will export an additional shapefile containing the upper right photogrammetric control point, its height, and the section number.

Export section will export an additional shapefile containing the section based on the highest outer points.

Thanks to Nils Müller-Scheeßel for the idea.

This can be used to show the line with the point of view.

Thanks to Nils Müller-Scheeßel for the idea.

Open the layer settings of the section -> Lables ->

Text -> Lable with '↓'

Placement -> [x] Line orientation dependent on position

Rendering -> Show upside-down lables -> [x] always

This can be very helpful while processing the drawings.

3. Run the calculation

Some hints for a good result:

• If you have a straight section you will have the best results.
• If sections are very long and not very straight, sometimes it is better to split them (we plan a function for the next version to do it the easy way for the user).

4. Accuracy

Getting values for the accuracy of the points.

When you open the attribute table of the rotated points, you will find the column distance.

This value represents the distance of each point to the calculated section between the points. The higher the value is, the worse the result will be.

If there is one point not in the line, this one will have a high distance. If you choose 0 in the original column used Points, this point will be excluded

in the calculation of the regression line, but the point will be rotated. This can be used to correct measurement errors.

5. Error handling

An error handler will check the data during the calculation

There are a few errors and warnings possible. All Errors will be shown in a red bar and in the ErrorLOG protocol in the protocol window (View -> Panels -> Log Messages Panel)

• A section needs min. 4 points. Error on section: XXX

Section XXX has 4 or less points.

• The view column of your data is inconsistent (either none or two different views are present). Error on section: XXX

The view of the sections contains different or no values for the points.

• The view value is not one of the four cardinal directions. Error on section: XXX

The view column holds another direction than N, E, S or W.

• Only 0 or 1 are allowed in the selection/use. Error on section: XXX

In the use column only 1 or 0 are allowed as values.

• Layer XXX is not projected. Please choose a projected reference system.

The coordinate system of the layer is not a projected one. Save the layer in a projected system.

• The z-value needs to be a float. Check the field type of the z-value

Save the column containing the z-value as float

You will get the best results if your work carefully in advance on the excavation and prepare a perfectly straight section!