The Line of Sight tool is used to calculate and investigate the intervisibility. Intervisibility is defined as the ability to see in a direct line of sight from one position on the earth’s surface to another, considering all the intervening terrain of the earth's surface.
- Distance - Distance form the source point.
- Value - The value of raster's cell at the given point.
- Visible - Whether the point is visible or not from the source point.
- Offset Required - The value denotes the required offset to make the point visible. If the value is positive, you need to raise the height. If the value is negative, you need to lower the height to make the point visible.
- XCoord - The X coordinate of the point.
- YCoord - The Y coordinate of the point.
The line of sight profile is divided into green and red line segments. The red and green line segments represent the invisible and visible points respectively from the source. You can generate line of sight profiles for multiple lines.
If you draw or select multiple lines on the map, you can see a corresponding number of profiles created on the chart. You can use the lock button on the profile, to lock editing of the selected profile.
A number of sample points are created between the source and destination along the line of sight profile. You can control these points using the Specify Sample Count checkbox. It helps you in the ease of analysis.
What is Offset ?
If a point is not visible from the source location then the MapInfo Pro Advanced suggests by what amount the height of the sample point should be adjusted (raised or lowered) to make the point visible from source. This value is called Offset value.