National Optical Astronomy observatory

WIYN Consortium

WTTM User Manual

WIYN Observatory

WTTM User Manual

Last Updated: January 28, 2005

950 North Cherry Avenue

Tucson, AZ 85719

Phone 520-318-8000

Table of Contents

Chapter 1 Introduction. 1

Chapter 2 Quick Start 3

Chapter 3 Configuring WTTM... 5

3.1 Choosing a beamsplitter and aperture. 5

3.2 WTTM Filters and CCD Characteristics. 8

3.3 Guide Star Selection. 9

3.4 WTTM Control Software & Parameters. 11

3.5 Data Acquisition Computer 16

3.6 APD Normalization. 16

Chapter 4 Observing. 17

4.1 Start of Night 17

4.2 Typical WTTM Observing. 18

4.3 Offsetting. 19

4.4 End of Night 19

Chapter 5 Technical & Engineering Run Results. 20

5.1 APD S/N.. 20

5.2 Ghost Images. 21

5.3 Use WTTM Aperture #5. 21

5.4 Image Quality Limits. 22

5.5 Improvements from Tip-Tilt 22

5.6 Spend Time to Focus Properly. 22

5.7 Stopping and Re-starting Acquisition. 22

5.8 WTTM Control Software Idiosyncrasies. 23

5.9 Wind Buffeting. 23

5.10 Turn the APDs off 23

5.11 Task and Update Frequencies. 23

Chapter 6 WTTM CCD Characteristics. 24

Chapter 7 WTTM Performance. 25

7.1 Typical Gains. 25

7.2 WTTM Throughput 25

7.3 Radial Dependence. 26

7.4 Using Non-Recommended Parameters. 27

Chapter 8 Data Handling. 28

8.1 Media. 28

8.2 Taping Using IRAF. 28

8.3 Taping Using UNIX.. 29

8.4 Writing CDs and DVDs. 29

8.5 Safe Taping. 29

8.6 Save The Bits. 29

Appendix 1 CLI Commands. 30

Appendix 2 Photometry Demonstration. 31

Appendix 3 The Optical System.. 34

Figures

Figure 1 WTTM Image Quality Improvement 1

Figure 2 QuickStart Flowchart 4

Figure 3 APD Count Rate as a function of Tip-Tilt Star Magnitude. 5

Figure 4 85/15 Beam Splitter Transmission Function. 6

Figure 5 95/5 Beam Splitter Transmission Function. 7

Figure 6 Kron/Johnson Filter Transmission Curves. 8

Figure 7 Sloan Filter Transmission Curves. 9

Figure 8 APD Count Rate as a function of Tip-Tilt Star Magnitude. 10

Figure 9 WIYN IAS Guide and Focus Star Fields. 11

Figure 10 Main Control GUI 12

Figure 11 Error Sensor Control GUI 13

Figure 12 Feedback GUI 13

Figure 13 APD Signal to Noise Demonstration.