User's Manual

DIGITALCONTROLINCORPORATED
DigiTrak Falcon F5
®
Operator's Manual 43
Locate Points (FLP & RLP) and Locate Line (LL)
The Falcon receiver locates the transmitter by detecting three specific places in the transmitter’s magnetic
field: the front locate point (FLP) ahead of the transmitter, the rear locate point (RLP) behind the transmitter,
and the locate line above the transmitter itself. The two locate points are indistinguishable from one another
by the receiver as they represent similar points in the transmitter’s field in front of and behind the transmitter
(see AppendixC: Projected Depth Versus Actual Depth and the Fore/Aft Offset on page69 for more
information about the transmitter’s magnetic field).
The locate line (LL) extends 90° to the left and right of the transmitter (perpendicular) when the transmitter is
at 0% pitch. It represents the location of the transmitter between the FLP and RLP. If you think of the
transmitter being the body of an airplane, its wings are the locate line.
Locate line does not equal the location of the transmitter.
Being over the locate line does not mean you are over the transmitter, which may be to
the left or right anywhere along the locate line. You must find the front and rear locate
points to find the transmitter, as is detailed on the next couple pages.
The most accurate tracking requires the use of all three locations to determine the position, heading, and
depth of the transmitter. A line passing through the FLP and RLP reveals the heading and left/right position of
the transmitter. The LL determines the position of the transmitter when the receiver is properly aligned
between the FLP and RLP (on the line).
1. Bird's-eye view (looking
down)
2. RLP (2)
3. LL (2)
4. Transmitter
5. FLP (2)
6. Drill rig
7. Bore path
8. Side view
9. Surface of ground
10. Transmitter at negative pitch
Geometry of FLP, RLP, and LL from Top (Bird’s-Eye) and
Side Views
Note how the RLP and FLP are equal distances from the LL when the transmitter is level.