A16.5 Surveying by distances from fixed points (polyline or polygon):
Level of expertise required for this Chapter: Intermediate; general Map Maker training
The product of a survey carried out by measing distances from two fixed points can be a polyline or a polygon. Map Maker will draw a polygon if the last coordinate in the xy file is the same as first one, as it is in the example. If the first and the last coordinates in the xy file are not identical a polyline will be drawn.
In the example the feature under survey is to the right of a line connecting Station 1 to Station 2, when viewed from Station 1. In cases where the feature under survey lies to the left of a line connecting Station 1 and Station 2, when viewed from Station 1, the distances measured must be entered into the xy file as negative numbers.
Set out two markers on the ground, Station 1 and Station 2, at points of known position. Then measure the distance from each station to Point 1, Repeat for the remaining points and record the survey data in a table similar to the one shown.
The process in Map Maker is the same as explained at Annex 16.2:
Main menu > Utilities > Text editor > Save as type: Map Maker survey data (xy) > Select folder > Specify file name > Save > Enter survey data (as shown below, starting with line DISTANCE and the x,y coordinates of Station 1 and Station 2, all separated by comma) > File > Save > OK
Main menu > Utilities > Vector utilities > Import files > Map Maker survey (.xy) > Import Map Maker survey data,step 1 window: Choose source xy file > Select folder and XY file from previous step > Open > Next step > Accept or specify file name > Finish > Yes > Confirm save
Load the file in Map Maker (Add Layer)