3.1.4.3.1- STATION POINTS

First of all, we will draw and reference stations. The .xvi image shows centerline with stations. Click on one of them. Point control panel will open. Therion will set type “station”. In “options” box, you'll see “-name X”, where X is station number (or name) as it is named on centerline data. It has been referenced automatically, because xvi image holds the necessary information to do it.

So -when working over .xvi images- you don't need to care about referencing drawed station points to real centerline points. This would not be the case if you were working over scanned sketches.

You can exit the “point insertion mode” by pressing “Esc” key, or by clicking twice in the same point. Now the red box at the bottom of the window is green, and shows a “select object” message.

Now you can click on points to select them. Once selected, you can move them by dragging.

To delete a point, select it, then go to “File commands”, click on “Action” menu, choose “Delete”, then press what is actually “Delete” button. Or select the point and simply press “Crtl-D”.

Each scrap needs to have at least two centerline-referenced station points. From these two points, scaling and rotating can be calculated, since we have point's position on screen (pixels) and point's coordinates (from centerline data). I usually reference all stations, not two.

If there aren't at least two referenced stations in the scrap, it must be scaled by hand. This is always the case when you select projection “None”. It is used to do cross-sections, so don't care about hand-scaling for now .

Scaling by hand is useful if you draw a handmade sketches of unsurveyed galeries too, because you probably know the last surveying point, but in unsurveyed galeries there are not any surveying point more (sic).