What are Layers? What's the difference between markers, routes, tracks, etc.?
In Terrain Navigator Pro, there are various ways to make modifications to the USGS maps and aerial photos. These modifications are stored as "Layers", which are saved automatically as they are created.
There are two basic types of layers. Some, such as markers, routes, and tracks, you create. Others, such as the street layer or custom grids, are added automatically. All of the layers can be identified and controlled by opening the View menu and choosing Layer Size/Visibility.
Currently, there are eight types of layers that can be used to directly annotate maps: Markers, Routes, Tracks, Labels, Range Rings, Range/Bearing Lines, and GeoPins. With these layer tools, a wide variety of edits can be performed on the maps.
Markers are single positions on the map. Each marker can have a unique symbol and color. Markers also contain a text label. Markers are useful for noting single objects on the map such as a building, a parking lot, or a campsite.
Routes consist of waypoints, connected by legs. A waypoint is a location along the route where a direction change takes place. Most often, Routes are used to plan hikes, where you have a starting point, one or more stopping points (summit, lunch break, etc.), and an end point. Routes can also be used to annotate pipelines and boundaries.
Tracks are free-form routes without waypoints. They can be drawn on the map in a variety of colors. Tracks are often used to illustrate trails, streams, and roads.
Labels are text annotations. They can be constructed with various outlines, backgrounds, etc. They are most useful to work around the limitations found in the built-in labels on markers and route waypoints.
Range Rings are concentric circles and are used to note distances from a point of origin. These are commonly used by search and rescue personnel to locate individuals and by those constructing communication towers.
Range/Bearing Lines are used to measure distances by heading, speed, time, etc. Two RBLs can be used to show points of intersection.
GeoPins are shortcuts to web sites, documents, photos, and other files on your PC. They can be used to display pictures of a hike or site plan, linked to web pages, or a myriad of other uses.
Polygons are shapes created to denote and measure area. Polygons can consist of multiple parts (such as a field that is bisected by a road) and/or contain holes (such as the area of a lake, not including an island.)
All of these Layers can be constructed on the map by selecting the desired tool and clicking on the map. Markers, routes and tracks may also be transferred to and from a compatible GPS Unit. To include layers on a printed map, choose "Print Layers" in the Print window.
Another type of layer is an Overlay. These are typically GIS files (such as shapefiles) that have been imported into Terrain Navigator Pro for display. These can include boundaries, property designations, and a host of other data sets. While you can use the Overlays option in the Layers menu to determine how an Overlay is to be displayed, the Overlay can not be edited beyond its basic shape. However, you can right click on any Overlay segment and create a route, track, and/or marker from that object.
The second basic types of Layers are constructed from data sets included with Terrain Navigator Pro. These include: NGS Benchmarks, the Custom Grid, Photo Labels, and Streets.
NGS Benchmarks are represented by the red triangles that dot the maps. Each benchmark is linked (via the Information tool) to a data sheet that describes it. NGS Benchmarks are commonly used by surveyors planning large construction projects. Unless these interest you, you may wish to turn them off by deselecting 'Benchmarks' in the Layer Size/Visibility control found in the View menu.
The Custom Grid is a grid system that you define that is overlayed upon the maps and photos. You will find the options to set this grid by opening the File menu and choosing Preferences, Custom Grid. This is especially useful when employing the Township/Range (PLSS) coordinate system. Note that the USGS has superimposed their own grid on many USGS maps. This grid (typically a UTM grid using the NAD27 datum) is embedded on the printed map and (as such) can not be removed.
Photo Labels are displayed on aerial photos to identify various points of interest. Using the Layer Size/Visibility control (in the View menu) you can determine which categories of label you wish to show.
Streets add a current layer of roads to the topographic maps and aerial photos. Since the USGS is no longer producing updated topographic maps (instead producing "National Map" aerial photos) you can use the Streets layer to keep updated with the latest changes.
There are some other features in Terrain Navigator Pro that are classified as layers. These include the Base Map, Distance Line, Find Circle, and GPS Icon.
The Base Map is the actual USGS map (or aerial photo.) In some cases, you may wish to hide the base map, leaving only the Street layer, or a complex system of routes that you created. This can be done by disabling the Base Map in the Layer Size/Visibility control (in the View menu.)
The Distance Line is a tool that is designed to make quick measurements and calculations. Unlike tracks or routes, the Distance Line is not saved into the current Project when Terrain Navigator Pro is exited.
The Find Circle appears whenever an object is located via the Find menu. For example, opening the Find menu and choosing Coordinates will put the red Find Circle around that location. Click on the Find circle to remove it from view, or disable it completely in the Layer Size/Visibility control (in the View menu.)
The GPS Icon is shown when live tracking is engaged. It can be set as an arrow, circle, car, or other object. It can be hidden using the Layer Size/Visibility control (in the View menu.)
As you can see, using the Layer Size/Visibility control (in the View menu) is essential to choosing the layers you wish to show or hide. Both broad categories (such as all routes), or individual features (such as a single marker) can be turned off or on.
Layers are also very versatile. By combining each of these types, a wide variety of annotations can be accomplished.
Software Training Videos
The Terrain Navigator Pro YouTube Channel contains many videos to help you make the most of TNP. Some relevant videos include:
Creating Layers from the Tools Menu (Part 1)
Creating Layers from the Tools Menu (Part 2)