According to MH / T60121999 International Civil Aviation Organization issued the "International Standards and Recommended Measures Airport" Annex XIV, obstruction light points low light intensity, medium light intensity and high light intensity three categories: 1, low light intensity obstruction light for the constant light, red, peak light intensity greater than 32.5cd, generally not alone, and must be in the light intensity, high light barrier with the use of obstacles. Such as 45 meters above the building and its facilities are equipped with multi-layer light intensity or high light barrier, in the light intensity or high light barrier between the lights can be set low light barrier. (Low light intensity obstruction light is red, effective light intensity 100cd ± 25%) 2, in the light barrier light according to light requirements are divided into three categories: A, medium light A-type obstruction light for the white flash, the effective light intensity 20000cd-2000cd, for more than 105 meters of buildings and facilities and background light strong obstacles or with high light intensity B type light with light use. B, the light intensity B-type obstruction light for the red flash, the effective light intensity 2000cd ± 25% for 105 meters below the buildings and facilities or with the light intensity A type, high light intensity A type of obstruction light with the use. 3, high light barrier light according to light requirements are divided into two types: A, high light intensity A-type obstruction light for the white flash, and in the day, evening or dawn and all-weather nighttime light intensity, effective light intensity were 200000cd ± 25% day; evening or dawn 20000cd ± 25%; night 2000cd ± 25% ; Mainly used for more than 150 meters above the building and its facilities to use, or in the light with obstacles to use. B, high light intensity B type obstruction light for the white flash, and in the day, dusk or dawn and night all-weather light intensity three layers of synchronous flash, the effective light intensity were 100000 cd ± 25% day; evening or dawn 20000cd ± 25% 2000cd ± 25%, mainly used for marking wires, cable towers and high-voltage transmission lines such as tower. Third, the distribution of aviation obstruction lights distribution 1, the obstacle on its obstruction light set should mark the obstacle of the highest point and the most edge (that is, as high and wide). 2, if the top of the object above its surface above 45 meters above the ground, must be added in the middle layer of obstacles, the distance between the middle layer must be no more than 45 meters and as much as possible (more than 100 meters in the city of tall buildings To consider the middle layer to add obstruction lights). It is advisable to avoid making residents feel unhappy when building blocks in the vicinity of cities and neighborhoods. General requirements from the ground can only see the scattered light. 3, the shape of the building blocks set up obstacles should be able to see from all aspects of the outline of the object, the horizontal direction can also refer to the distance of 45 meters to set the barrier lights. 4, for 105 meters of high objects, facilities or cable tower, roof tower, etc., should be set in the top of the light intensity A-type obstruction lights, and white flash, the lower part of the set of red light intensity B-type obstacles light. 5, more than 150 meters of ultra-high objects (such as radio and television towers, large span cable-stayed bridge, etc.) should be set at its top high light A type obstacle lights, and should be in the high light barrier lights with the use. According to MH / T60121999 International Civil Aviation Organization issued the "International Standards and Recommended Measures Airport" Annex XIV, obstruction light points low light intensity, medium light intensity and high light intensity three categories