Aircraft Video GPS

The obvious answer was to put the videographic system (VideoMap) to a full blind test, to see if it could deliver. Ian Scott reached an agreement whereby if VideoMap could produce the claimed sub-meter accuracy, the developer/operator (Terra Surveys Ltd of Victoria, BC) would be awarded the contract to map the rural sections of the WKP transmission system. If the accuracy was not met, the operator agreed to pay half of the helicopter costs for the trial.

VideoMap was flown along a 10 km test corridor, where a number of pole positions had previously been determined by a differential GPS ground survey. The results met West Kootenay Power’s criteria so convincingly that Scott requested the company provide all the remaining pole positions on the test line, to serve as benchmarks when evaluating the accuracies of the ground crews to be used in the urban areas !

Subsequently, both WKP’s transmission and much of their rural distribution network, spanning an area from Princeton, BC in the west, to Creston in the east, was flown in 7 days. The survey identified and positioned over 34,000 poles in approximately 3,200 km (2,000 miles) of flying. Each pole was described by casting, northing and height above sea level, plus up to three different descriptive categories were included per pole. Table 1 shows typical text descriptions.

Table 1: A Typical Utility Pole Description

E’ing	N’ing	Elev’n	Category	Struct. Equip.
455713.27	5431684.63	422.33	UNDERBUILT POLE	TRANS
455716.08	5431775.27	419.13	UNDERBUILT POLE
455718.36	5431867.11	420.61	UNDERBUILT POLE	TAP
455720.68	5431946.18	422.58	UNDERBUILT POLE
455722.72	5432028.52	422.88	UNDERBUILT POLE	TAP
455725.11	5432111.45	423.62	UNDERBUILT POLE
455727.26	5432194.74	423.06	UNDERBUILT POLE	TRANS TAP
455729.20	5432273.25	425.39	UNDERBUILT POLE	TRANS
455733.43	5432374.27	424.97	UNDERBUILT POLE	TRANS TAP
455737.43	5432470.94	425.64	UNDERBUILT POLE