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Introduction to software. This presentation gives you an overview of the MaxIm DL software used for CCD control and data reduction and Excel spreadsheets for data analysis and display.
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Introduction to software This presentation gives you an overview of the MaxIm DL software used for CCD control and data reduction and Excel spreadsheets for data analysis and display. It is intended to familiarise you with some of the procedures you are likely to use, not to provide detailed instructions, so You do not need to take notes All the information is contained in detail in the Observatory Manual which you should read carefully If in doubt – ask a tutor
The Observatory Manual • The observational projects require you to: • - set-up and move the telescope to acquire targets • - set-up and use an instrument to take measurements a CCD camera (projects 1, 2, 5, 8) or a spectrometer (project 3) • - ‘reduce’ the data (calibrate it and turn it into useful information • - ‘analyse’ the data (obtain scientific results) • You will have learnt about the principles of operation of telescopes, CCDs and spectrometers from Observing the Universe • The Observatory Manual* provides the details required to perform each of the required tasks using the equipment at the OAM • *There are likely to be changes to some procedures due to modifications to the equipment available.
Computers and Filename Conventions • Laptops in each dome labelled by telescope name • PCs in laboratory numbered 1 to 7 • All data stored and saved on lab PCs in folders within C:\OU (=my documents) • A folder has been placed on each pc/laptop for each week of SXR208 e.g. year04week01pc01 (or year04week01Tycho) • (year 2004, SXR208 week 1, PC number 1) • For each night: • Create a new folder for the raw data, e.g. Sep10_p01_Sun_Tycho (September 10, project 1, group “Sun”, telescope “Tycho”) • Create a working folder for all analysis (Sep12_p01_Sun_Tycho_work) to avoid over-writing files
Part 1 Introduction to MaxIm DL • Used for: Control of CCD • Image processing • Menu based system • Many functions for image processing • Main features for SXR208 described • All information in Observatory manual • MaxIm DL is used for all the telescope-based projects photometry (1, 2, 5 and 8) and spectroscopy (3)
Starting Up To start, double click on the MaxIm DL icon on desktop. Main menus “View” Toolbar Main display area
Top level menus • File: File manipulation, e.g. opening, closing, saving, printing • Edit: Copying, pasting, adjusting image orientation & display • View: Telescope (not used), CCD control, zooming, information • Analyse: Astrometry and photometry data reduction • Process: Calibrate images and manipulate pixel values • Window: Select between open images and adjust display • Filter, Color , Plug-in: not required for SXR208 • Help: Searchable help and MaxIm DL tutorials
Opening an image • Remember the name conventions • Opening files: Open command in File menu Directory Files Selected file Click to open Set to All files turn off Information on selected file
Navigating an image • The images produced with the CCD camera are too large to be displayed on a computer screen at full resolution. • Navigate the image using the bars on the right hand side and bottom of image. • Zoom in and Zoom out commands in the View menu, or shortcut icons, or the magnification field next to them on toolbar. • ZoomWindow command in the View menu: shows a magnified part of the image without changing the overall zoom. • If the images do not have the desired orientation then use theFlip, Mirror, Rotate Right,Rotate Left,orRotate 180 commands from the Edit menu.
‘Quickstretch’ box number of pixels vs. intensitylevel Automaticlevel options Displayedbrightnesslevellimits Screen Stretch window • Click on the Screen Stretch Window command in the View menu • 5 ways to change contrast/brightness of a displayed image • Processes only change image display, not the data
Information window • Click on InformationWindow in the View menu, or use the icon Cursor (in aperture mode) Central aperture Background annulus Operation mode
Night vision command • To prevent loss of night vision in the dome when observations have started • Select Night Vision in the View menu. • In the default red mode, all menus, dialog boxes, etc., turn red. • (Icons and toolbar buttons are not affected).
CCD camera control using MaxIm DL • The laptops in each dome are used to control the CCD cameras • These instructions are for the photometry projects
CCD camera CCD camera mounting screws STL1001E CCD Camera Microfocuser Connection to Controller focus port Connection to controller autoguider port Power cable Indicator lights Connection to laptop USB port
CCD control window - setup • Open using CCD control in the View menu or by clicking icon • Setup tab used to connect and start up CCD camera • Select CCD and Filter wheel, Connect to CCD, Turn on cooler
CCD control window - settings • Use to change CCD display orientation • (all other settings should not be changed) Adjust orientation of images tomatch CCD orientation (nominal position needs Flip Horizontally and Flip vertically
CCD control window - expose • Used for taking individual images (files are not automatically saved)
CCD control window - focus • Provides repeated readout and display to aid in finding and focusing • Make sure image type Light and appropriate filter are selected using the Expose tab, before going to the Focus tab.
CCD control window - sequence Automaticallysaves fileswith namein a standardform Use sequencenumber touniquelyidentifyframes Setup sequences from the options menu (see next slide for details) then use the start button to begin observations
Setup Sequence is used to prepare and select a series of exposures which can be re-used during the night.
CCD data reduction using MaxIm DL • Data reduction is performed on laboratory PCs • Data are transferred from the dome laptop to a laboratory pc using USB memory sticks (256 Mb ~ 125 images)
Preparing calibration files Set calibration commandfrom the Process menu Used to set up which frames are to be used forsubsequent calibration 3 ‘Groups’ containing1 or more bias, flat field or dark frames are set up This button should domost of it for you!
Calibrating frames • Open the images that you wish to calibrate using theOpen Command from the File menu. • To calibrate the currently selected image: • Click the Calibrate command from the Process menu • To calibrate all open images that have not already been calibrated during this MaxIm DL session: Click the CalibrateAll command from the Process menu. Aligning and combining frames • Used in some projects for combining frames provides improved signal-to-noise of observations • Use the Combine command from the Process menu.
Aperture photometry • Click the Photometry command in the Analyse menu to open thePhotometry window and the Information window • Procedure: • - select the image (or series of images) for photometry • - select an aperture size within which photometry is performed, and an annulus within which sky background is measured • - ‘tag’ objects: • Reference star: all photometry is performed relative to this star • Check star: object(s) used to check that the reference star is constant in brightness • Object: target object for photometry • Moving Object: moving target object for photometry (asteroid) • - inspect light curve to check data and remove ‘bad’ data • - write data to a file (to load into excel)
‘right click’menu to change Aperture etc
Reference star Check star Object Data can be saved to a .csv (comma separated variable) file
Part 2 Data analysis and graph plotting using Excel • Excel is used for processing of the reduced data • Files output from MaxIm DL photometry can be read by Excel
Spreadsheet structure • Worksheet can be formatted: - Autocorrect options can be turned off - Row and column widths can be changed - Rows, columns or cell can be deleted or cleared - Fonts, colours, backgrounds etc can be changed
Data entry and formulae • Numbers or text can be entered directly into a cell • Formulae are entered using cell references, mathematical operators and stored functions. • Example: Cell B2 contains contents of cell A1 added to contents of cell A2 Apply formula Cancel formula Input line Function library
Using formulae Formulae follow basic rules for arithmetic: Operations performed in order: ^ (to the power of); * and / (multiply and divide); + and (add, and subtract). There are many built-in functions, e.g. =SUM(A1:A10) sum of cells A1+A2+…+A10. =AVERAGE(A1:A10) average of the values in cells A1+A2+…+A10. =STDEV(A1:A10) standard deviation of values in cells A1+A2+…+A10. =INT(A5) integer part of the number in cell A5. =EXP(A5)e to the power of the number in cell A5. =SIN(A5) sine of the number (in radians) in cell A5. =LOG(A5,n) logarithm to the base n of the number in cell A5. If n is not specified it defaults to 10.
‘Dragging’ • To select several cells at once: • Place the cursor (an open cross) over the cell, hold left mouse button down while sliding the cursor across the spreadsheet. • To copy the contents or formula in one cell to other cells: • Either: - Select a cell or cells - use the copy or cut commands in the Edit menu; • - click on the destination cell (top left if several cells copied) - use the paste command from the Edit menu. • Or: - Place the cursor on the small square in the corner of the cell (the cursor will change into a narrow cross). - hold down the left mouse button and drag the cursor down a column and/or across a row. - the value or the formula will be copied to all the cells dragged over.
‘Dragging’ formulae • Cell references in a formula arerelative to the selected cell • If you drag or copy a formula: the cell references are automatically updated in the new cells. • B3 contains =A2+A3 • To drag a formula without updating the cell references use $ character e.g. =$A$1+A2 B3 now contains =$A$1+A3. • $A$1 fixes column and row • $A1 fixes column only • A$1 fixes row only • Be careful when dragging, copying and pasting formulae. Check the results.
Entering data from files • Click Open in the File menu and the Open window appears. • - select the required folder • - select All files in the File of Type field • - double-click on chosen file name or icon. • - data from the .csv file will appear in a new Excel spreadsheet • - paste the data into your working spreadsheet • (select the cells you require and use the Copy and Paste commands from the Edit menu)
Formatting data in cells • Click the Cells command in the Format menu.
Plotting graphs – the Chart Wizard • Select Chart command from theInsert menu • X-Y scatter option
The resultinggraphneeds formatting
Formatting the chart • To change the appearance of a chart an item must be selected. • Move the cursor over the graph to illuminate item labels • Place the cursor over an item and single click. The region or object will be highlighted in some way where appropriate, ‘handles’ will appear for moving or resizing • Place the cursor over an item and double click: When appropriate a window will open with options you can adjust. • Resize the image and plot area, remove the grey background, remove gridlines, adjust legend etc.
To reformat Y axis double click over Value Y axis Changes styleand values ofaxis and labels Click here toreverse axes(most negativemagnitude isbrightest)
Best-fit straight line • Using Add Trendline command: • - Click over one of the symbols to select the data series to be fitted. • - Click on Add Trendline command in the Chart menu
Remember… • Always read the instructions • Detailed of the software can be found in the Observatory Manual • Seek help within your group • Ask a tutor