The Distance options from the DTM Query Menu allow you to query distances relating to two or more points. You should note that when querying distances you cannot change where to search for points during the operation of the option. You cannot look for the first point in the current model and change to looking for the second point in the current backcloth. To do this, you must choose to search for both points from either the current model or the current backcloth.
Point to Point Distance
The Distance Pt to Pt option allows you to query the distance from one point or station to another. You will be asked to indicate the two points or stations concerned and the dialog box below will be displayed.
The dialog contains the co-ordinates of the two points together with the differences in their co-ordinates. The bearing and polar angle of the line from the first to the second point are also displayed as is the plan distance.
If both the points have a valid height, the slope distance is displayed together with the slope of the line. The slope is shown as both a “1 in x” and a percentage. Negative values in the slope fields signify that the line is downhill.
The buttons Point 1 and Point 2 allow you to query the start and end points of the segment and a simple report will be given in a report view. A Report button allows you to generate a report of the values in the dialog box in a report view.
Point Offset from a Line
The Distance Offset option allows you calculate the perpendicular offset distance of a point from a base line defined by two other points. Firstly, you will asked to indicate the base line points and then a series of further points.
For each indicated point, n4ce will project the co-ordinates onto the base line and calculate its distance along and offset from that base line. The results of each calculation will be displayed in a dialog similar to that shown below.
The dialog contains the co-ordinates of the indicated point together with the co-ordinates of the projected point whose height is calculated by linear interpolation from the base line. The differences between the indicated and projected points are also displayed.
The distance along and offset from the base line are shown in the Offset Distances group. The first value is the plan distance along the base line point from the first base line point to the projected point. The other values are the plan and slope distance of the line from the projected point to the indicated point.
The Slopes and Angles fields relate to the line between the projected point and the indicated point.
The Base Line button allows you to display the point to point distance dialog box for the base line points. The Dimension button allows you to add up to three dimensions to the indicated point. These are DST which will store the plan distance along the base of the projected point, OFFS which will store the plan offset of the indicated point from the base line and, if applicable, DZ which will store the vertical offset of the indicated point from the first base line point.
The Distance Running option allows you to calculate the cumulative distance along a series of points. You will be asked to the points in sequence and once completed, the dialog shown below will be displayed.
The list control displays the vertex count and the indicated point codes, numbers and co-ordinates. To the bottom of the dialog are the cumulative plan distance and, if applicable, the cumulative slope distance.