Abstract: A selected one of a plurality of underground utility conveyances(14--14) may be located in an enclosure (10) by providing each conveyance with an electronic marker (18). Each marker is responsive to a first RF signal from an electronic marker locator (32) operated by a utility worker. Upon receipt of the first RF signal, the electronic marker associated with the conveyance of interest responds by broadcasting a second RF signal containing information indicative of the conveyance. The second RF signal is received and processed by the electronic locator marker to locate the conveyance and ascertain information related thereto.

Abstract: Optical signals that would otherwise transit a first fiber (12), but for a break therein, may be cut-over to a second fiber (16) by clamping the first fiber at first and second spaced locations thereon upstream and downstream, respectively, of the break. Clamping the first fiber creates a microbend at each of the first and second locations at which optical signals exit from, and may be injected into, respectively, the first fiber. The second fiber is likewise clamped at first and second spaced locations thereon to create a pair of microbends at which optical signals may be injected into, and extracted from the second fiber, respectively. Once the first and second fibers are clamped in this fashion, the optical signals extracted from the first fiber at the first location are coupled into the second fiber and then extracted therefrom for injection into the first fiber at the second location thereon.

Abstract: Precise location of a buried utility conveyance (10) is achieved by impressing on the conveyance low frequency conveyance-locating and conveyance confirmation signals, the later being pulsed in a particular pattern unique to the conveyance to be located. A first sensor (22) detects a first magnetic field radiated by the conveyance upon receipt of the conveyance-locating signal. An array (24) of sensors (26.sub.1 -26.sub.5) detects the second magnetic field radiated by the conveyance upon receipt of the conveyance-confirmation signal. A processor (32) coupled to the sensors (26.sub.1 -26.sub.5) precisely vectors the location of the conveyance from the second magnetic field strength sensed by each sensor (26.sub.1 -26.sub.5).

Abstract: A Fiber Analysis System (10) detects threats to a buried underground fiber (10) by delivering two optical sub-signals, split from a single beam, into opposite ends of the fiber so the sub-signals traverse the fiber in opposite directions. The sub-signals are recombined into a beam whose characteristics are detected by a detector (24). The output signal of the detector (24) is compared by a processor (26) to different reference values stored in a data base (28) representing different detector output signals corresponding to different fiber conditions. By matching the detector output signal to a reference value associated with a particular fiber condition, the processor can determine whether a potential threat exists.

Abstract: Automatic measurement of the quality of each splice (17) in an optical fiber (12) is accomplished by a combination Automatic Time Domain Reflectometer and Optical Switch unit (18) situated at one of the fiber remote from the location (16) where the splice is made. Technicians at the splice location (16) control the combination Automatic Time Domain Reflectometer and Optical Switch unit (18) by launching commands thereto via a laptop computer (32) that are communicated across a wireless communication channel via a wireless transceiver (30). Fiber loss measurements made by the combination Automatic Time Domain Reflectometer and Optical Switch unit (18) are relayed to the technicians at the remote splice location across the wireless channel for processing on the computer (32) to determine the splice quality.

Abstract: An underground utility conveyance (10) may be precisely located by impressing both a locating tone and a confirmation tone on the conveyance. The locating tone is an RF signal that produces a first field that radiates above the earth that is sensed by a first, above-ground signal detector (22) to establish the general location of the conveyance. The confirmation tone is a near-DC signal that produces a second, field having a relatively limited radiation path. A second detector (24) is inserted into the earth at successive places in the region where the conveyance is located to establish its precise location.