TRANSPORT CANADA

Transport Canada is a governmental regulatory organization overseeing air, rail, marine and road transportation.
Transport Canada sets the standards on marking and lighting of towers.
The purpose of obstruction lighting and marking is to ensure that an obstruction to air navigation remains visible at a range sufficient to permit a pilot to take appropriate action in order to avoid the obstruction by not less than 305m(1,000 Ft) vertically within a horizontal radius of 610M (2,000 Ft) from the obstruction.

            
BEACON              OBSTRUCTION LIGHT

To view the full standard please visit

LIGHTING AND MARKING SPECIFICATIONS
     Part VI - General Operating and Flight Rules

TRANSPORT CANADA'S WEBSITE
    Canadian Aviation Regulations (CARs)