Why are the views inverted through telescopes

Software development by Jürgen Goldan

To the homepage juergen.goldan.org

Status: 04/11/2021


- New version Teleskop V4.97.1, new directory structure and setups
- Track elements for ATLAS C / 2020 R4

Detailed status of updates under version info
If you have any problems or questions, please email Jürgen Goldan.


1. General

The current Windows version comes with Microsoft VS2017 and is derived from an earlier version on ATARI 1040ST. Functionalities have largely been retained. The documentation from 1995 is here.

The program is operated on a console, without graphics and mouse. I do not find a common Windows application with a mouse very practical at night in cold weather. The control of the program can be controlled with a few buttons (especially the Space), but also with a GamePad.

The program shows how:


The screen is divided into different areas:

objectwith information about the set object
CET / CESTthe current time
STZthe current sidereal time
AstronomicCoordinates of the mount (are not exactly the object coordinates)
MountHour angle and declination of the mount (pitch circles)
Menuis the main menu (activated by space)
objectis the menu for selecting objects for positioning and initialization
statuswith program status and information to the user

I assume no liability for damage to telescopes, mounts and accessories that result from incorrectly driving the mount. When positioning the telescope, always ensure that there is a free swivel range. The telescope can be driven against the column or mount due to incorrect controls (incorrect position).
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2. Features

Use of the LX200 protocol
Approaching planets, minor planets, comets, satellites, terrestrial and other objects
Objects are kept in editable files
Initialization of the telescope with all objects possible, through earthly so to start also during the day
Approaching objects in the daytime sky
Due to the parking position, the telescope can be started immediately later
Triggering a camera via an additional cable (jack plug)
Simple representation of the visible sky with object selection
All functions can be batched
Determination of placement errors (SUPER mode)
Control via GamePad possible (also wireless)
Observation log of all executed functions / objects with notes

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3. Installation

The program is installed via a setup. The first step is the query of the installation directory. Here shouldn't be a usual directory under C: \ Programs can be used, since these directories are always write-protected from Windows 7 onwards and there are no write permissions. It should be a directory on a secondary partition like D: be used. You are then asked for the options:


All additional data files and objects should be installed for the first time. Entries in the start menu are created. After the installation, the following files and directories are created:

File / directorynecessarydescription
   telescopeMain directory
Teleskop.exe XMain program TELESCOPIC
Telescope.rsc XNGC and IC objects (binary)
XInput9_1_0.dllDll for GamePad (not under XP)
Setup telescope XSettings file (default)
Komando.txtList of the last commands on the command line (only after the first start)
SimplePhotoViewer.exeImage display program (VIEW)
Click.exeProgram for triggering a DSR camera
Sky.exe XSky view program
GfaWin23.Ocx XOCX file for Sky.exe (GfA-Basic)
Sky_Mes.kat Xall Messier objects for Sky.exe
Sky_Stern.kat X60 bright stars to initialize for Sky.exe
Sky.var XStars for Sky.exe (binaer)
Sky.dat XConstellations and Shadows for Sky.exe
   Telescope \ dataDirectory with all objects
Messier.cat Xall Messier objects
Star.cat X60 bright stars to initialize (source: FK4)
Constellation cat Xall constellations
Ost.datTable with open star clusters
Kst.datTable with globular clusters
Ga.datTable with galaxies
Nebel.datTable with mists
Herschel.datTable from list by Herschel (all NGC)
Double dateTable with double stars
Multiple.datTable with multiple double stars
Special dateTable with special objects
Publik.datTable with common objects
listown object list
*.jobJobs with commands for the execution of functions
   Telescope \ Data \ ObjectsDirectory with path elements
Pluto.cpl XOrbit elements for Pluto
* .cplOrbit elements for minor planets
* .komOrbital elements for comets
* .tleTwoLineElements files for satellites
   Telescope \ Data \ StarDirectory with files on constellations
* .datTable with objects per constellation
   Telescope \ Data \ ImageDirectory with images of the objects (planets, Messier, NGC)

The program starts in a console. The console should have at least 80x25 characters. The size can also be changed at runtime. The outputs look misaligned for a short time, but are automatically updated again.
Select 'Lucida Console' or 'Consolas' as the character set, no raster character set (Greek characters are then missing), the font size as desired. Everything under properties the console.

If Windows have problems starting, the current runtime for Microsoft VC2017 may have to be installed.
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4. Call and start

If the program is started without an argument, the Setup telescope File loaded and these settings used. Since all files with the extension *.telescope are linked to the program by the setup, the program can be started with these settings as an argument by double-clicking a * .teleskop file.

The coordinates, data for the mount and the settings used are saved in the settings file. This file can also be written by the program, whereby changes are adopted.
This file is self-explanatory with comment lines (# ..).

Functions from a menu are shown below.

The program is controlled using the functions in the main menu. To activate this (title becomes inverse) the buttons Space or return to press. The selection bar can now be accessed using the arrow keys up down be moved. Through the buttons Left Right the bar jumps to the first / last menu item. The main menu has three views to which the function can be used. A function can be triggered by pressing a single key using the characters on the yellow background.

The program tries to connect to the set mount immediately when it starts. If this does not work, then select the function and the correct setting in the menu. Saving the settings with the Save function for the next start of the program.
When the program is started, there is also a query to initialize with the parking position. The parking position is stored in the settings file. What is special about the program is that terrestrial objects on the horizon can also be used for this via azimuth and altitude (see Section 6.4 Parking position).

4.1 Initialize (SYNC)

If a parking position has not yet been set, the current actual coordinate of the telescope must be set manually. This is done using the function. The object menu is then activated. An object itself, hour angle + declination or coordinates with right ascension + declination can be set. For the most precise initialization, the program contains 60 bright stars, which are distributed evenly over the entire sky. In the star catalog used (file Star.cat) the own movements are also stored with high precision.
The initialization of the telescope can always be repeated over the course of an observation night.

4.2 Positioning (GOTO)

In the following, all objects in the sky can be approached using the function. The object menu is activated again and an object can be selected.
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5. Operation

The normal operation of the program is in the. The telescope can be moved with the arrow keys.
Only a few buttons are required for further control of the program:

  • Space bar to activate the menu and select it in a menu,
  • Enter to confirm a selection in the menu (also works with space bar),
  • Arrow keys to move in the menu, buttons left / right jump to the beginning / end in the menu,
  • Arrow keys also control the telescope in the hand control (faster),
  • ESC cancels all functions and goes back to manual control,
  • The button's C, D, E, F, I, K, L, H, N, O, P, R, S, 1, 2, 3 allow quick selection in the main menu (indicated by a light symbol in the menu).

All these functions can also be controlled with a GamePad using its buttons and joysticks.

           (Image source: https://gamepad-kontroller.arukereso.hu)

The OK, Esc, POS .. and SKY functions are directly possible using the colored buttons.
3 speed levels are possible for driving the telescope (standard LX200). The analog stick (left) can be used to drive directly through all three levels by deflection. The D-pad next to it limits travel to level 1 for more precise approach to an object. With the right analog stick, the speed is limited to level 2 for slow driving.
Scrolling through the menus is also possible with all sticks. The active bar moves over up / down and with left / right to the beginning or end of the menu.
The wireless version of the GamePad via BlueTooth is a step up. This means that there is no longer any tangled cables on the telescope.
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6. Features

The central core of the program is a command line through which all functions are controlled. The command line can be entered directly and the program can be completely controlled with it. Since this is too cumbersome, there is of course a "graphic" menu for the most important functions.

The main menu is activated by pressing the space bar (visible in the title of the menu). Since the main menu contains more titles than shown, a total of 3 menus are set up. These can be switched through in the menu or with buttons 1-3.
After activating the positioning or initializing functions, the right object menu was used to select an object or enter coordinates.
The command line is then evaluated internally by the interpreter and the functions are executed. All commands that are unknown to the interpreter are executed as an external program. This means that the program is open to additional functions.
The program structure is shown in this illustration (still created on Atari):


Here is a list of all commands and here is a short documentation with the most important functions of the program.

6.1 Command

A command line can be entered directly using the command or the K key. Use the arrow keys up / down to switch between the last commands. The command line cannot be edited, only the Backspace key has a function. The last commands are retained even after a program restart.

Here are the important functions of the program in sub-items:

6.2 Jobs

The above command lines can also be transferred to the interpreter from a file (* .job). This allows automatic processes, also time-controlled, to be carried out. This can also be observation sequences, also with photographic triggering (CLICK command).
Saved jobs can be selected and executed using the command or the R key.
Examples here as Endless_03sec.job, Click_Series_6x20.job, Test.job.

6.3 Sky overview

With the function in the menu or the S key, an external program to display the current starry sky with constellations, Milky Way, initialization stars, Messier objects and planets (all selectable) is started. All objects can be selected for the control to approach.
There are also shadows here. The program can also be started independently.
The information about the control of the program (times can be changed) are shown to the right of the sky display.
This picture shows the shadowing at the Volkssternwarte Hannover:

The display can be controlled using buttons:

   A. - Shading on / off
   B. - Lines of the constellations on / off
   E. - Ecliptic on / off
   G - Grids alternate in equatorial-azimuthal-out
    I. - Stars for initialization on / off
   M. - Measurement objects on / off
   N - Constellation names on / off
   P. - Planets on / off
   S. - Stars on / off
   X - Inversion of the representation
   / * - one day back / forward
   - + - one hour back / forward
  < > - one minute back / forward
   J - jump to the current date (now)

This help is also visible in the Sky window to the right of the compass rose. All settings are retained for the next call.

6.4 Determine installation errors

In super mode, with the initialization of stars (max. 20), the calculation of the installation errors is used through an adjustment. Activation in the menu with or by the SUPER command.
A log file after starting up and initializing 10 stars is here.
The output initially contains the determined values ​​for the installation errors with the accuracies (s0 = total accuracy) and a table with the stars used: serial number, object, location 1/2, July date, hour angle [h], dec. [ °], Error Stw ['], Error Decl. ['], Accuracy of the asterisk ['] and the object name.
The installation errors determined by the program are shown here:


The mistakes are:

  • Errmaz is the azimuth error, the deviation from north.
  • Sleeves is the elevation error, the deviation from the pole height.
  • Errmoa is the deviation of the opt. Axis at right angles to the declination axis.
  • ErrFrq is the frequency error as a factor to get to the target tracking frequency.
  • Stw0 is an offset value for the hour axis (from initialization).
  • Delta0 is an offset value for the declination axis (from initialization).

These errors determined in super mode can be entered in the telescope file used. The units are in minutes of arc.
Here is an excerpt from the log with the result of a SUPER trip with 10 stars for the installation on my balcony.

6.5 Parking function

Parking the telescope is an important function. This position is set in the setup, whereby the program also starts with this position. The command for this is on the first menu level. Since positions can also be used as azimuth with height, I use the chimney of the Leinhausen power plant in Hanover as the parking position.


This goal is good to set during the day as well as at night. With this I can also observe astronomical objects (Mercury, Venus, bright stars) during the day!
When approaching the park position, please note that the mount may not stop (there is no command for this under LX200) and must be switched off manually. This works with the FS3.

6.6 Night mode

The screen can be dimmed for night operation (in the menu or key D), a screen with the program information is shown here
with my settings:


The colors of the program can also be inverted using the function in the menu or the COLOR command.

6.7 Trigger the camera

With the additional program Click.exe as a console (command CLICK, in the menu), a DSR camera can be triggered via a COM port.
Arguments are the duration in seconds plus optionally the number of the COM port. Without the port specification, the next free port is used.
Call: click Sec Port. Without arguments, 0.5 seconds is triggered. On the COM port, RTS and DSR are set to high for the duration.
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7. Objects

A large part of the objects can be selected via the menu. All objects are also interpreted in one command. The objects are used for the POS .. and INIT .. commands.
The following objects are possible:

Number of argumentsexampleimportance
is the name of an object like sun, m13, ngc2354, halley, ..
the first character is a '!' this is how a satellite is searched for in the TLE files
(big / small important for satellites)
232.5 12are south azimuth and altitude (°)
2+1 -0with a sign are differences (°) for south azimuth and altitude
42 46.2 56 23Hour angle (hh mm.mm) and declination (° ')
4+0 10 -4 0signed are differences (° ') for R.A. and declination drive
62 34 1 -12 53 0are R.A. (h m s) and declination (° '")
72 34 1 -12 53 0 2000like 6 arguments, but still with the year of the equinox

Keys can still follow for an object. This sets e.g. the constellation, the distance and other things. These keys are an argument followed by a control character.A ':' is followed by a comment, which is displayed in the object window. Here are the possible elements:

Control charactersexampleimportance
S.S.Object is a star
D.D.Object is a double star
M.M.Object is a multiple double star
PlNPlNThe object is a planetary nebula
E.E.Object is an emission nebula
EastEastObject is an open star cluster
KStKStObject is a globular cluster
GaGaObject is a galaxy
,boo,(= Comma) Abbreviation 3 characters of the constellation
m5.8mBrightness of an object in magnitude
b8.9bBrightness of the companion of a double star
p310pPosition angle to the companion of a double star
l80000lDistance in light years
'40'Object diameter or distance of a double star in [']
"23.4"Diameter of object or distance of a double star in ["]
:: Tea kettle, 5x5 degreesComment on the object

Example of an object from the file Special date:

By POS! ISS and below RUN Endless_3sec.job the ISS can be observed. This also works in the daytime sky! These commands can also be triggered more easily in the menus.
I captured an observation of the ISS with the Canon as a film. Here you can see the movement and the jumping for tracking after 3 seconds.

For Satellite positions I used code from 'libpredict' from Github. Copyright 2015 Asgeir Bjørgan (LA9SSA), a free software for processing TLE files. For Telescope, the files must be converted to TLE extension instead of a TXT extension. The files can be downloaded from the Internet.
Control of the satellites goes through the object selection and switching through to satellites. In the command line, satellites are preceded by a '!' enables. About the job Endless the telescope can then follow the satellites in a loop.
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8. All commands

Commands are entered in the main menu with the command at the bottom of the console. Previous commands can be repeated using the up / down arrow keys. Here is an alphabetical list of all possible commands. Upper / lower case does not matter, but here the command is always shown as UPPERCASE:

commandvia menuimportance
BEEP Generate beep tone (useful for RUN)
CLICK XTriggering of the DSR camera via COM port. Arguments: duration [port [pause]]
CLS Restore screen
COLOR XChanges the color display black / white
DEBUG XActivate / deactivate debug output
DEL [n] Delete the last or number n of the initialization objects (for SUPER)
DIM XSwitch to night mode
FILE = file XSetting the data file (def. LIST) with objects
FLIP Change telescope position for Arduino
FOLLOW = [0/1] Set or query the following of the object
FS3 = [n] Query / set the speed of the hand box FS3 (0..9)
HELP XOverview of all commands
INFO XInformation about the settings and program
INIT objectXSet position on object
INIT LOAD no Xinitialize to the object no in the file
CALIB Test drives of the engines under gearing (see protocol)
LS [path] Show directory contents
MAN [sec] [[hh]: ss]Manual control for sec seconds or absolute time
wildcards * are possible for times
    man 21:45 waits until 9:45 p.m.
    man: * 0 waits until the next full 10 minute
    man: ** wait until the next full minute / td>
MAN = freq Query the max.frequency for manual driving / td>
NOTE text .. Write a note in the protocol
PARK XMove telescope to park position and stop (SLEEP)
PORT XSelect a COM port via the menu
PORT = Change the control port (COM1, COM4, ​​..)
POS objectXdrive on object
POS LOAD no Xmove to the object no in the file
POS LOAD text XMove to the object with a fulfilled text search in the file
PROTO XLogging on / off (in file yymmdd_Protokoll.txt)
QUIT XQuit the program after query
RESET Read in the settings file * .teleskop again
RUN file [n]X'file' contains commands and is executed, opt. Start from line n,
Command 'GOTO line' possible for jump in line
Command SET sets variables (max. 10, like: SET Time = 20)
Output then with% var% (as in command line Windows)
You can calculate with +, -, =, <,>, (the last one returns 1 or 0)
IF query THEN command
Global variables:
% OBJ_NAME% for object names
% OBJ_MAG% for object brightness in mag
% OBJ_AZIMUTH% for object azimuth
% OBJ_HEIGHT% for object height in degrees
Other jobs can be called in a job
    SET no = no + 1
    IF Nr> 10 THEN GOTO 20
    NOTE approached% OBJ_NAME%, height =% OBJ_HEIGHT%
SATBEFORE = [sec] Set or query advance on satellites in seconds
SAVE XSave the settings file * .teleskop
SAVEPOS Xsave current position (see FILE =)
SECURE Change fast and 2 times start-up (compensation of gear backlash)
by maintaining the gear backlash and reversing
SEND ... String ... send to serial port
SHOW Coordinate display on / off
SLEEP Mount is stopped (only Arduino)
SKY Xsimple sky view with act. Location (Sky.exe)
STATUS [text] Output text in the status window
STOP Stop motors (emergency stop)
SUPER [file]Xextended initialization with installation error on / off
'file' contains outputs from an initialization (from the log)
SWAP alpha | delta Change the logic of the driving directions
UPDATE Update orbit elements for satellites via the Internet (Visual.tle)
VAR XShow variables (for SUPER)
VIEW XDisplay of the positioning objects (image) (on / off)
TIME Setting the PC time

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9. Supported controls

The motors are controlled via the LX200 protocol. Compatible with:

  • LittleFoot Vpower by Anand Rajiva (page no longer accessible).
  • Arduino with Stepper Motor Shield and software dSPIN_TELESCOPE by Igor Vlasic.
  • manual to build an Arduino box, with parts list at Reichelt.
  • FS2 by Michael Koch. Danger: The telescope position still has to be converted manually via the FS2.
  • TeenAstro (FS3) an open source project by Charles Lemaire.
    This is what the command is for FS3 = .. important because my program changes the speeds and the manual control thus maintains a defined speed (values ​​0..9).
    Here is a picture of my control system FS3, version 2.4.1.
  • other telescopes with LX200 protocol.
  • an ASCOM driver is in preparation.


  • Stepper motors at Oriental motor
  • Timing belts and pulleys types HTD 3M 1F with a width of 9mm at Mädler

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  • Setup for the latest version 4.97.1 from April 6th, 2021, with the programs Astro.exe, Click.exe, Sky.exe and a viewer for pictures
    (with XP the use of a GamePad is not installed).
  • Version 4.97.1 with all object images, but 288 MB! Alternatively, the images can also be installed later:
  • In order to see images of the objects, this ZIP file (292 MB) with all object images must be in the directory Data \ image be unzipped! These images were in part from Rob Gendler created.
  • Ephemeris program Astro for all objects of the program (is a test program for all calculations).
    Is in the same directory as the main program Telekop.exe to discard.

    Here the visibility of the ISS and AJISAI (older date as examples).
  • Runtime for Microsoft VC2017 (redistrubution).
  • Sample jobs: A collection of useful jobs in a ZIP file.
  • Program TeenAstroConfig Version 2.4 to write and save the settings for the newest one TeenAstro Control (FS3).

  • Program ArduinoSetup Version 1.7 for writing and saving the settings (EEPROM) for the Arduino's software dSPIN_TELESCOPE.
    Sample files for this in a ZIP file.

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Current path element files for storage in the Objects directory

  • All current objects (April 9th, 2021) with their path elements in a ZIP. Unpack these files (> 90x) and store them in the Objects directory.
  • Comet LEONARD C / 2021 A1 in December 2021 up to 4.0 mag and 0.23AE earth distance on December 12th, 2021!
  • File visual.tle with TLE orbit elements for all visible satellites, also with ISS.
    A worthwhile satellite is there AJISAI (Nickname disco ball) 7-8 mag for binoculars or telescope.
  • Interstellar asteroid Oumuamua, also 1I / 2017 U1, object with a size of approx. 400 x 40m, discovered on October 19, 2017, see APOD (comparison with SF-Roman Rendezvous with Rama from Arthur. C. Clark!).
  • Minor planet (LEO) Didymos with closest approach to October 02, 2022 of 0.0753 AU to the earth. Maybe a mission planned by NASA and ESA.

If you like the program, I would be very happy about one donation looking forward.
This can easily be found here PayPal respectively.
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11. My own mount

I have a modified NP mount myself, converted with 2 stepper motors Oriental PX245M-02A (400 steps). The picture shows the mount with a refractor 80 / 540mm. The optics are from Lichtenknecker, the tube was self-made.


It is driven by a toothed belt 9mm (Mädler) via a gearbox of 16 and 30 teeth. Data:

  • Hour 1: 270 (108000 steps)
  • Declination 1: 135 (54000 steps)

The motors run with a TeenAstro 2.4.1 control with 8 (R.A.) and 16 (Delta) microsteps and can be positioned at a speed of 900x! A full turn of the telescope takes about 1.6 minutes. Control via Windows software.

Here is another example with dSPIN_TELESCOPE and Arduino while driving with 200x (simulation of t = 03h00, Dec = -20: 00 to the zenith and back again):

Click on the picture to start:

Since 2018 I have converted to a Meade SC4 "/ 1000mm and since 2019 with FS3, version 2.4.1. Here is an example with the FS3 when driving at 900x (from the west to Venus and back on 07/21/2019):

Click on the picture to start:

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  • To my program Astro32 for astronomical calculations and star map displays. This program can also be used to read the same object files with the path elements.
    This also makes it possible to load the object files directly by double-clicking and to calculate and display the current object.


Checked with