Subsections

• OBE_MODE
• Parameters
• Description
• Usage
• Last Update
• Author

FOCUSOBE

OBE_MODE

CISCO

Parameters

Parameter	Default Value
	CISCO
DATASET_ID	DS0000
OBJECT	"FOCUSING"
EXPTIME	NOP
FILTER	NOP
SLITX	NOP
SLITY	NOP
NSAMPLE	NOP
Z	!TSCL.Z
DELTAZ	0.1
NFRAME	3
SELECT	MANUAL

Description

Do focusing using OHS/CISCO.

This command changes focus-Z value of the telescope from (Z+ 2*DELTAZ) to (Z- 2*DELTAZ) with interval DELTAZ and obtain NFRAME frames at each focus position. It then measures the FWHM of the stellar image, fit the FWHM-Z relation by a hyperbola to calculate the best focus-Z, and set the Z value to it.

Usage

If SELECT=AUTO/SEMIAUTO, do following. When the frames of 3rd position have obtained, single image is displayed on the "OHS_Online" skycat of OWS (Figure below). Also, "QDAS System" window appears.

Push "Click Points Start" and enclose the stellar image with a square box. When finished, push "Click Point End", and push "SET".

Otherwise, these procedures are done automatically.

When finished, the plot of FWHM-Z relation and the best focus position are displayed in "QDAS plot" window as below.

Last Update

2000/12/18

Author

George Kosugi, Tomoyuki Taguchi, Kentaro Motohara