The Pickering Seeing Scale

The Pickering Seeing Scale

대기 안정도를 판단하고 기록하기에 딱히 정확한 판단 근거가 없던 차에 우연히 알게된 분류 스케일입니다.

마침 동영상도 있어 대략적으로 감을 잡을 수 있어 공유 차원으로 블로그에 정리합니다.

http://uk.geocities.com/dpeach_78/pickering.htm에서 참조하였습니다.

Below you will find an animated version of the Pickering scale of rating atmospheric turbulence. This was produced using Abberator V2, and using Pickering's comments on the appearance of the Airy pattern at a giving rating.

The scale was devised by William H. Pickering (1858-1938) using a 5" (13cm) refractor.

Animations produced by Damian Peach.

Pickering 1 rating - Very Poor. Pickering2 rating - Very Poor.

(1) Star image 2x the diameter of the 3rd diffraction ring - Star image 13" in diameter.

(2) Star image occasionally 2x the diameter of the 3rd ring.

Pickering3 rating - Very Poor. Pickering4 rating - Poor.

(3) Star image about the same diameter as the 3rd ring (6.7") and brighter at the centre.

(4) Airy disk often visible. Arcs of diffraction rings sometimes seen.

Pickering5 rating - Fair. Pickering6 rating - Fair to Good.

(5) Airy disk always visible. Arcs frequently seen.

(6) Airy disk always visible. Short arcs constantly seen.

Pickering7 rating - Good. Pickering8 rating - Good to Excellent.

(7) Disk sometimes sharply defined. Diffraction rings seen as long arcs or complete circles.

(8) Disk always sharply defined. Rings seen as long arcs/complete circles, always in motion.

Pickering9 rating - Excellent.Pickering10 rating - Perfect.

(9) Inner diffraction ring stationary. Outer rings occasionally stationary.

(10) The complete diffraction pattern is stationary.