* It calculates the azimuth and elevation of celestial objects and can send them to the Rotator Controller or other plugins to point an antenna at that object.
* It can plot drift scan paths in both equatorial and galactic charts.
* It can send the target to the Sky Map plugin, to display associated imagery in a variety of wavelengths. It can also use the Sky Map to set the target.
* The plugin can communicate with Stellarium, allowing Stellarium to control SDRangel as though it was a telescope and for the direction the antenna is pointing to be displayed in Stellarium.
* It has built-in models for calculating the position of the Sun and Moon, as well built-in coordiates for a few of the most significant radio objects,
but can also use NASA JPL's SPICE toolkit or Horizons API for targetting other solar system objects, such as asteroids, comets, planets, planetary satellites and some spacecraft.
* For Jupiter decameter radiation (DAM) observations, it can calculate and plot the phase of Io and Ganymede, relative to Jupiter's Central Meridian Longitude (CML) on a chart showing emission probability.
* It can plot the positions of major solar system bodies in the Solar System Map.
* The epoch used when entering RA and Dec. This can be either J2000 (which is used for most catalogues) or JNOW which is the current date and time.
* The units used for the display of the calculated azimuth and elevation. This can be either degrees, minutes and seconds or decimal degrees.
* Whether to correct for atmospheric refraction. You can choose either no correction, the Saemundsson algorithm, typically used for optical astronomy or the more accurate Positional Astronomy Library calculation, which can be used for >250MHz radio frequencies or light. Note that there is only a very minor difference between the two.
* API key for openweathermap.org which is used to download real-time weather (Air temperature, pressure and humidity) for the specified latitude (6) and longitude (7).
* How often to download weather (in minutes).
* Air pressure in millibars. This value can be automatically updated from OpenWeatherMap.
* Air temperature in degrees Celsius. This value can be automatically updated from OpenWeatherMap.
* Relative humidity in %. This value can be automatically updated from OpenWeatherMap.
* Height above sea level in metres of the observation point (antenna location).
* Temperature lapse rate in Kelvin per kilometre.
* What data to display for the Solar flux measurement. Data can be selected from 2800 from DRAO or a number of different frequencies from Learmonth. Also, the Learmonth data can be linearly interpolated to the observation frequency set in the main window.
* The units to display the solar flux in, either Solar Flux Units, Jansky or Wm^-2Hz-1. 1 sfu equals 10,000 Jansky or 10^-22 Wm^-2Hz-1.
* The update period in seconds, which controls how frequently azimuth and elevation are re-calculated.
* The IP port number the Stellarium server listens on.
* Which rotators are displayed on the polar chart. This can be All, None or Matching target. When Matching target is selected, the rotator will
Select the date and time at which the position of the target should be calculated. Select either Now, for the current time, or Custom to manually enter a date and time.
By default the date and time is the local. Check the UTC button is use UTC instead.
Displays the Solar flux density. The observatory where the data is sourced from, frequency and units can be set in the Settings dialog (5). The field is updated every 24 hours, or can be manually by pressing the download Solar flux density data button (3).
- To manually enter RA (right ascension) and Dec (declination) of an unlisted target, select Custom RA/Dec.
- To allow Stellarium to set the RA and Dec, select Custom RA/Dec, and ensure the Stellarium Server option is checked in the Star Tracker Settings dialog.
- To select a target from NASA JPL Horizons database of solar system objects (asteroids, comets, planets, planetary satellites and some spacecraft), select Horizons in the target source (12).
Major bodies will be added to the target list. Other bodies can be targetting by typing in their numeric ID.
- To select a target from a SPICE SPK file, select SPICE in the target source (12).
* Cassiopeia A, Cygnus A, Taurus A, and Virgo A at ultra-low radio frequencies - https://research.chalmers.se/publication/516438/file/516438_Fulltext.pdf
Selects the source of targets listed in the Target list (11).
- SDRangel: built-in targets as listed in (11).
- SPICE: Solar System bodies from a SPICE SPK file.
- Horizons: Solar System bodies from NASA JPL's Horizons database.
SPICE SPK files are available from [NASA JPL's NAIF website](https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/).
SPK files can be specified in the Star Tracker Settings dialog (5).
When Horizons is selected, the Target list (11) will be populated with major bodies from the Horizons database. Other bodies can be specified by entering their ID manually.
The Horizons database includes asteroids, comets, natural satellites, planets, the Sun, some spacecraft and dynamical points (L1 etc) and barycenters.
[Horizons Manual](https://ssd.jpl.nasa.gov/horizons/manual.html). Using the Horizons API requires an internet connection.
When target is set to Custom RA/Dec, you can specify the right ascension in hours of the target object. This can be specified as a decimal (E.g. 12.23, from 0 to 24) or in hours, minutes and seconds (E.g. 12h05m10.2s or 12 05 10.2). Whether the epoch is J2000 or JNOW can be set in the Star Tracker Settings dialog.
When target is set to Custom RA/Dec, you can specify the declination in degrees of the target object. This can be specified as a decimal (E.g. 34.6, from -90.0 to 90.0) or in degrees, minutes and seconds (E.g. 34d12m5.6s, 34d12'5.6" 34 12 5.6). Whether the epoch is J2000 or JNOW can be set in the Star Tracker Settings dialog.
When target is set to Custom Az/El, you specify the azimuth in degrees of the target object. The corresponding RA/Dec and l/b will be calculated and displayed.
When target is set to Custom Az/El, you specify the elevation in degrees of the target object. The corresponding RA/Dec and l/b will be calculated and displayed.
 
In order to assist in determining whether and when observations of the target object may be possible, an elevation vs time plot is drawn for the 24 hours encompassing the selected date and time.
Some objects may not be visible from a particular latitude for the specified time, in which case, the graph title will indicate the object is not visible on that particular date.
When the target is set to a Satellite Tracker, this chart is plotted based on the Satellite's current position only. It does not take in to consideration the satellite's movement. For that,
The Solar flux vs frequency plot, shows the solar flux density data from the Learmonth observatory as a function of frequency. The measurements are made at 245, 410, 610, 1415, 2695, 4995, 8800 and 15400MHz.
 
When the target (11) is set to Custom Az/El and the Sky temperature plot is displayed, a curve showing the drift scan path over a 24 hour period will be displayed.
To setup a drift scan through a particular target object, first set the target (11) to that object. This will set the azimuth and elevation to point at the object.
You may want to set the Time (8) to Custom and a few hours in the future, so that the elevation is at a maximum when pointing at the target.
Then switch the target to Custom Az/El and Time back to Now, and the drift scan path that sweeps through the object will displayed.
Two images of the Milky Way are available: a purely graphical image and one annotated with the names of the major spiral arms and a grid with distance and galactic longitude.
When used with the Radio Astronomy plugin, markers corresponding to the position of HI clouds calculated from a marker on the spectrogram, can be plotted to display the estimated position of the cloud.
An animated PNG file can then be created from multiple plots to show how the markers follow the positions of Milky Way's spiral arms as galactic longitude is varied.
This process requires a marker to be placed on a peak in the spectrogram and then the  button to be pressed to add the current plot to the animation.
The process then repeats, by selecting the next measurement at a different longitude in the spectrogram and marking the appropriate peak, and then adding it to the animation.
When all frames have been added, the animation can be saved to a PNG file by pressing .
To start a new animation, press .
The Solar System Map shows the positions of the bodies selected in the Settings Dialog (5). Positions can be plotted on either a linear or logarithmic scale. The positions are displayed top down on the ecliptic plane.
The map will be centered at the body selected in the combo box. Select '-' to be able to pan the map with the mouse.
<h3>Jupiter CML and Moon Phase</h3>
The Jupiter CML and Moon Phase plot is for assisting with Jupiter decameter radiation (DAM) observations. It displays the phase of either Io or Ganymede against Jupiter's Central Meridian Longitude (CML) overlaid
The moon is plotted at the selected date and time (8). The white line shows the path and time of the current or next visible pass of the moon.
Underneath the chart, the elevation of Jupiter in degrees, the Central Meridan Longitude in degrees and moon phase in degrees, are shown for the selected date and time (8).
The Central Meridan Longitude is the System III longitude of Jupiter that is currently facing Earth, taking in to account light travel time.
A moon phase of 0 degrees is at the far side of Jupiter, while 180 degrees has the moon directly between Jupiter and the Earth.
<h3>Light or dark theme</h3>
Click on this icon  to switch between light and dark themes for the charts.
The Star Tracker feature can send the overhead position of the Sun, Moon and target Star to the Map. These can be enabled individually in the settings dialog. The Moon should be displayed with an approximate phase. Stars (or galaxies) are displayed as an image of a pulsar.
The Star Tracker feature will send the target RA/Dec, observation point (antenna location) and antenna beamwidth to the Sky Map.
If the Star Tracker is set as the Source plugin in the Sky Map, pressing the Track button in the Sky Map will result in the Sky Map tracking the target
* Enter Right Ascension/Declination or press "Current object" to get RA/Dec of currently selected object
* Press "Slew" to send the RA/Dec to Star Tracker
Star Tracker will continually send the RA/Dec of its target to Stellarium and this should be displayed in Stellarium with a crosshair/reticle and the label SDRangel (or whatever name you entered for the telescope).
To see the rough field of view of your antenna, open the Ocular configuration window and under Eyepieces, add a new eyepiece with name SDRangel.
Set aFOV to the half-power beam width of your antenna, focal length to 100 and field stop to 0.
Then select the SDRangel telescope reticle and press Ocular view.
* Solar radio flux measurement at 10.7cm/2800MHz is from National Research Council Canada and Natural Resources Canada: https://www.spaceweather.gc.ca/forecast-prevision/solar-solaire/solarflux/sx-4-en.php
* Solar radio flux measurements at 245, 410, 610, 1415, 2695, 4995, 8800 and 15400MHz from the Learmonth Observatory: http://www.sws.bom.gov.au/World_Data_Centre/1/10
* 150MHz (Landecker and Wielebinski) and 1420MHz (Stockert and Villa-Elisa) All Sky images from MPIfR's (Max-Planck-Institut Fur Radioastronomie) Survey Sampler: https://www3.mpifr-bonn.mpg.de/survey.html
* 408MHz (Haslam) destriped (Platania) All Sky image and spectral index (Platania) from Strasbourg astronomical Data Center: http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/410/847
* Milky Way image from NASA/JPL-Caltech: https://photojournal.jpl.nasa.gov/catalog/PIA10748
* Icons are by Adnen Kadri, iconsphere and Erik Madsen, from the Noun Project Noun Project: https://thenounproject.com/
* Icons are by Freepik from Flaticon https://www.flaticon.com/
* Io & Ganymede Phase vs CML plots from Jupiter radio emission induced by Ganymede and consequences for the radio detection of exoplanets, Zarka et all, 2018: https://www.aanda.org/articles/aa/full_html/2018/10/aa33586-18/aa33586-18.html
* Sun image from Solar Dynamics Observatory, NASA
* Mercury image from Messenger, NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.
* Venus image by NASA/JPL-Caltech
* Blue Marble by crew of Apollo 17.
* Moon image by NASA.
* Mars image Viking Orbiter, NASA/JPL-Caltech
* Phobos image by NASA/JPL-Caltech/University of Arizona
* Deimos image by NASA/JPL-Caltech/University of Arizona
* Jupiter enhanced image by Kevin M. Gill (CC-BY) based on images provided courtesy of NASA/JPL-Caltech/SwRI/MSSS
* Io from Galileo by NASA/JPL/USGS
* Ganymede from Juno by NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill
This uses a gnomonic projection. To change to cylindrical/plate carree, with the centre of the galaxy at the centre of the image, edit header.hdr to have:
CTYPE1 = 'GLON-CAR'
CTYPE2 = 'GLAT-CAR'
CRVAL1 = 0
CRVAL2 = 0
Then convert with:
mProjectQL source.fits dest.fits header.hdr
FITS files can be scaled (Scale > ZScale) and exported to .png with SAOImageDS9: https://sites.google.com/cfa.harvard.edu/saoimageds9
