Directional Scanner
The directional scanner is a built-in device which can detect objects within a specified range (up to 2,147,483,647 km, or about 14.355 AU) from your ship, and within a specified angle. Notice that the directional scanner will never give you a warp-able point. All it can do is telling you whether an object is there.
Using the Directional Scanner
The directional scanner can be accessed from the second tab in the window brought up by pressing CTRL+F11. The tab contains a field for entering range, a slider for choosing the angle of the scan, and a checkbox to apply your overview settings.
Range and Angle
The distance of your scan is typed in manually. You can set it between 1 km and approximately 14.355 AU. However you can only specify this range in km, and therefore a conversion is required. 150 million km is about the same as 1 AU (the actual conversion is 149,597,871 km:1 AU). To quickly perform a max-range scan, you can fill the range field with multiple 9s until you can no longer put any more in, and it will default to the max range.
A slider bar is available to choose the scan angle from preset values at several key stages between 360 degrees and 5 degrees. Together, the angle and range parameters define a cone shaped scan area, with the apex being your ship (or a sphere/hemisphere if the angle is set to 360 degrees/180 degrees, with your ship being at the sphere's center) and the axis of the cone being a vector shooting from your ship away from you, and toward the direction which the camera is pointed at (see below).
A more intuitive representation of the scan area can be brought up by pressing F11 out in space. In the bottom section of the new window that pops up, a green triangle represents the current scan area, and the grey area is your field of view. This map, however, is a flat plane, and one should remember directional scan is performed in 3D.
Overview Filter
The last option is to choose if the current overview setting is used. With the option unchecked, anything that can be picked up by the scanner will be displayed, potentially making desired information difficult to be picked out. Selecting this option will apply your current overview filters to the scan results, essentially turning the scan result into an extension of your overview.
It should be noted, however, objects that cannot be added to the overview, such as probes, will never show up on the scanner if you choose to apply overview settings.
Directional Scan and the Camera
The "Directional" part of directional scan is quite unique in that it is controlled by moving the camera around, and has nothing to do with your ship's bearing. It may be helpful to imagine directional scan as a flashlight. By moving the camera, you are essentially pointing the flashlight toward the direction you want to check.
Because camera manipulation is involved, it is also necessary to enable brackets, since otherwise you will not know where exactly you are pointing your camera at. With brackets enabled, aligning the camera is as easy as overlapping your ship's indicator with the target's icon. Check Varius Arcturus' Overview Guide for how to enable brackets.
Locating Ships
An important use of the directional scanner is to find ships such as PVP targets. Notice that the scanner only returns ship names and types, but not the pilot's name.
Most people will start by checking if the target is located at a place that can be easily warped to, such as planets, stations, or asteroid belts. For example, you can start by using a small-angle scan on a planet's "cluster" (including the planet itself, its moons and associated belts, as well as nearby stations) from a distance away. You can then warp to the planet and check its surrounding celestial bodies with the scanner in the event that your first scan turns out any potential target.
Again, notice that the directional scanner will never give you a warp-able point to the target ship itself. Ships sitting at off-grid safespots will necessitate the use of combat probes. However, directional scans can still help by pointing out the general position of the target, thereby reducing the time needed for probing and the chance that the target will move away upon seeing your probes on their own directional scan.
Other Uses of the Directional Scanner
Another important function of the directional scanner is to locate potentially hostile ships before they get to you. As was mentioned above, it is very helpful to pulse the scanner to check for ships or combat probes close to your current location. It will generally take at least 4 probes at 2 AU away to probe you out. So if you see that many probes on a 360 degrees scan at, for example, 4 AU, you need to prepare defensive measures. Like was mentioned before, to have probes show up on your directional scan, the overview setting box should be cleared.
In lowsec/null-sec, directional scan can also be used to check for POS at moons you intend to travel to, as a defended POS can kill your ship very quickly.
The directional scanner can also be used to check gates for gatecamps. Of course, you will need to establish an off-grid bookmark near the gate beforehand.
Links
- Scanning Guide from Grismar's wiki, contains some nice pictures showing how the scan area is shaped.
- Blog entry from EVE Newb, general information on intel gathering, showing the directional scanner in action.