Log Book Entry No.14

Days, Calendar Created: 12 Sep 2013 19:57:01 Days, Calendar Last Revised: 19 Sep 2013 15:31:38 Person PedroPaiva Text Test of Python Telescope Control

After turning telescope on, it successfully received GPS signal and did not started the usual RA movement.

The Camera was connected to Python via MaximDL
Telescope and Focuser connected to Python via the POTH Hub
Coordinates in agrement between Scope, Python and Stellarium

Target was set to be -0.1║ RA from current telescope position and Python SlewToTarget was tested.
Telescope moved the right amount and stopped, both telescope and Python alerted when ready.
A second test was made with +0.5║ RA. Also successfully.

Still with small (-0.1║ RA/DEC and +0.5║ RA) movements, Python SlewToCoordinates was tested successfully.

With the tests done, the telescope was moved to Vega via controled movements on Stellarium
Vega was inside the Camera Range, demonstrating that the Park Method works.
Vega was recentered (-0.01 on RA) and the telescope was manually synced.
During this test, movements as small as 0.003║ on RA proved to have no effect whatsoever.

The next step was to test the focuser and the camera.
First, while still on continuous mode of the camera, the Python-Focuser connection was tested.
Python can read the position and move the focuser. Units are steps. 1 step = 20Ám

Having confirmed that one can move the focuser with Python, Vega was taken out of focus to test if we could focus the star using a small

step = -2000
new = 100
i = 0
prin = True
while abs(step)>50:
    old = new
    time.sleep(0.5)
    val = []
    for j in range(3):
        cam.Expose(0.1, 1)
        while not cam.ImageReady:
            if prin:
                print 'Step:', step
                prin = False
            else:
                time.sleep(0.1)
        cam.SaveImage('c:/Users/dome-pc/desktop/development/pythonscripts/astropy/new/userdata/testImg.fit')
        ap.load('test', ap.var.usrPath+'testImg.fit')
        m = ap.fitBrightest('test', fixAngle=True)
        val.append(m.values['sigy'])
    new = mean(val)
    if new > old:
        step = -round(step/2)
    POTHFocuser.Move(step)
    while POTHFocuser.IsMoving:
        if not prin:
            i = i+1
            print 'Image:', i, '  psf:', new
            prin = True
        time.sleep(0.5)

and it's Python
Image: 0  psf: 100
-2000
Image: 1  psf: 5.52986378126
-2000
Image: 2  psf: 4.7682139585
-2000
Image: 3  psf: 4.63297472825
-2000
Image: 4  psf: 4.53466837512
-2000
Image: 5  psf: 4.42683230931
-2000
Image: 6  psf: 3.50235534344
-2000
Image: 7  psf: 3.18247227685
-2000
Image: 8  psf: 2.31374459737
1000.0
Image: 9  psf: 2.59153415468
1000.0
Image: 10  psf: 1.1543044854
-500.0
Image: 11  psf: 4.32859550035
-125.0
Image: 12  psf: 4.57442264323
-32.0

which can be used to generate the following plot:
PSFvsFocuser.png

During the tests, a cloud covered the target but the time was enough to show that the script still have room for improvement and can work.

Telescope was parked and disconnected.
Camera was also disconnected.
Everything was turned off and covered.

Back to: LogBookAstronomy

LogBookForm
Subject Test of Python Telescope Control
Status thumbs-up

Physics WebpagesRHUL WebpagesCampus Connect • Royal Holloway, University of London, Egham, Surrey TW20 0EX; Tel/Fax +44 (0)1784 434455/437520

Topic revision: r4 - 19 Sep 2013 - PedroPaiva

 
This site is powered by the TWiki collaboration platformCopyright © 2008-2018 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding RHUL Physics Department TWiki? Send feedback