Friday, February 17, 2017

KStars 2.7.4 for Windows is released!

Glad to announce the release of KStars v2.7.4 for Windows 64bit. This version is built a more recent Qt (5.8) and the latest KF5 frameworks for Windows bringing more features and stability.

This release brings in many bugs fixes, enhancements for limited-resources devices, and improvements, especially to KStars premier astrophotography tool: Ekos. Windows users would be glad to learn that they can now use offline astrometry solver in Windows, thanks to the efforts of the ANSVR Local solver. The ANSVR mimics the online server on your local computer; thus the internet not required for any astrometry queries.

After installing the ANSVR server and downloading the appropriate index files for your setup, you can simply change the API URL to use the ANSVR server as illustrated below:

In Ekos align module, keep the solver type to Online so it would use the local ANSVR server for all astrometry queries. Then you can use the align module as you would normally do. This release also features the Ekos Polar Alignment Assistant tool, a very easy to use spot-on tool to polar align your mount.

Clear skies!

Thursday, February 16, 2017

Ekos Polar Alignment Assistant Tool

When setting up a German Equatorial Mount (GEM) for imaging, a critical aspect of capturing long-exposure images is to ensure a proper polar alignment. A GEM mount has two axis: Right Ascension (RA) axis and Declination (DE) axis. Ideally, the RA axis should be aligned with the celestial sphere polar axis. A mount's job is to track the stars motion around the sky, from the moment they rise at the eastern horizon, all the way up across the median, and westward until they set.

In long exposure imaging, a camera is attached to the telescope where the image sensor captures incoming photons from a particular area in the sky. The incident photons have to strike the same photo-site over and over again if we are to gather clear and crisp image. Of course, actual photons do not behave in this way: optics, atmosphere, seeing quality all scatter and refract photons in one way or another. Furthermore, photons do not arrive uniformly but follow a Poisson distribution. For point-like sources like stars, a point spread function describes how photons are spatially distributed across the pixels. Nevertheless, the overall idea we want to keep the source photons hitting the same pixels. Otherwise, we might end up with an image plagued with various trail artifacts.

Since mounts are not perfect, they cannot perfectly keep track of object as it transits across the sky. This can stem from many factors, one of which is the mis-alignment of the mount's Right Ascension axis with respect to the celestial pole axis. Polar alignment removes one of the biggest sources of tracking errors in the mount, but other sources of error still play a factor. If properly aligned, some mounts can track an object for a few minutes with only deviation of 1-2 arcsec RMS.

However, unless you have a fancy top of the line mount, then you'd probably want to use an autoguider to keep the same star locked in the same position over time. Despite all of this, if the axis of the mount is not properly aligned with the celestial pole, then even a mechanically-perfect mount would lose tracking with time. Tracking errors are proportional to the magnitude of the misalignment. It is therefore very important for long exposure imaging to get the mount polar aligned to reduce any residual errors as it spans across the sky.

Several polar-alignment aids exist today, including, but not limited to:

1. Polar scope built-in your mount.
2. Using drift alignment from applications like PHD2.
3. Dedicated hardware like QHY's PoleMaster.
4. Ekos Legacy Polar Alignment tool: You need to take exposure of two different points in the sky to measure the drift and find out polar error in each axis (Altitude & Azimuth)
5. SharpCap Polar Alignment tool.

Out of the above, the easiest to use are probably QHY's PoleMaster and SharpCap's Polar alignment tool. However both software are exclusive to Windows OS only. KStars users have long requested support for an easy to use Polar Alignment helper in Ekos leveraging its backend.

During the last couple of weeks, I worked on developing Ekos Polar Alignment Assistant Tool (PAA). I started with a simple mathematical model consisting of two images rotated by a an arbitrary degree. A sample illustration of this is below:

Given two points, we can calculate the arc length from the rotation angle, and hence the radius. Therefore, it is possible to find two circle solutions that would match this, one of which would be the mount's actual RA axis within the image. Finding out which solution is the correct one turned out to be challenging, and even the mount's own rotation angle cannot be fully trusted. To be able to uniquely draw a circle, you need 3 points. So it was suggested by Gerry Rozema, one of INDI venerable developers, to capture 3 images to uniquely identify the circle without involving a lot of fancy math.

Since it relies on, PAA has more relaxed requirements than other tools making it accessible to more users. You can use your own primary or guide camera, given they have wide-enough FOV for the astrometry solver.

Moreover, the assistant can automatically capture, solve, and even rotate the mount for you. All you have to do is to make the necessary adjustments to your mount.

The new PAA works by capturing and solving three images. It is technically possible to rely on two images only as described above, but three images improves the accuracy of the solution. After capturing each, the mount rotates by a fixed amount and another image is captured and solved.

Since the mount's true RA/DE are resolved by astrometry, we can construct a unique circle from the three centers found in the astrometry solutions. The circle's center is where the mount rotates about (RA Axis) and ideally this point should coincide with the celestial pole. However, if there is a mis-alignment, then Ekos draws a correction vector. This correction vector can be placed anywhere in the image. Next the user refreshes the camera feed and applies correction to the mount's Altitude and Azimuth knobs until the star is located in the designated cross-hair. It's that easy!

Ekos PAA is now in Beta and tests/feedback are highly appreciated.

Wednesday, November 23, 2016

New Supernovae Data Source in KStars!

The initial support for Supernovae in KStars was added back in 2011, but it relied on parsing an HTML page using a Python script to extract the necessary information on the latest discovered supernovae. It was obviously a very crude and hackish way to get the data, and I longed to rely on a better source for our data.

The Harvard page we were relying on for supernovae updates suddenly stopped posting any further updates, its last update was made in 2015. Thankfully, we discovered a new gold trove of information: The Open Supernovae Catalog project!

Every small orange dot is a supernova!

Before this project was created, the state of open and accessible data for supernovae was severely lacking in the astronomical community. Thanks to the Open Supernova Catalog, KStars is now again properly displaying old and newly discovered supernovae across the cosmos! The data is available by a JSON file that includes the supernova metadata required in KStars. It can be updated by the user from the data menu.

I'd like to especially thank Dr. James Guillochon, an an ITC Fellow at the Harvard-Smithsonian Center for Astrophysics, for his excellent support to make Supernovae in KStars possible!

Sunday, November 20, 2016

KStars 2.7.2 for Windows is released

Less than a month from the release 2.7.0, KStars v2.7.2 for Windows 64bit is now available for download on KStars website! Get it now and give it a go.

The new release features many minor improvements and bug fixes including very fast startup time (about 300% faster) in addition to more streamlined Ekos GUI for capture and schedule modules. Images captured with Ekos on Windows would now conform to legal filenames in Windows when using ISO 8061 time stamped files.

Unfortunately, a few problems remain in this release most importantly is that KStars does not gracefully closes, it always remains in the background and must be terminated explicitly by the Windows task manager. This bug was supposed to be fixed by Qt 5.8 but alas it is still affecting Qt 5.8 in emerge. Once fixed by Qt/KDE, we shall make another release addressing this issue. 

Saturday, November 19, 2016

Multiple notifications across multiple monitors in KDE Plasma 5?

I have 3 monitors, and on each monitor, I have a Plasma panel at the bottom. When any notification pops up, I get 3 notifications on each monitor. I have a full fledged panel on each monitor with everything including task bar and system tray.

As you can imagine, this can get annoying pretty fast. Thanks to IRC and Bhushan Shah who proposed this solution, simply remove the system tray from the panels on the secondary monitors, and just keep the system tray on the primary monitor. This way, you will only get one-notification popup on each monitor instead of multiple ones!

To achieve this, first click on the hamburger icon in the panel to edit the panel. Then hover the mount over the system tray area where you get a popup like below that enables you to remove the system tray plasmoid.

Wednesday, November 2, 2016

KStars Lite 1.0.0 is released on Google Play!

A couple of days after the release of KStars 2.7, the KStars team is happy to announce the availability of KStars Lite for Android, now available on the Google Play Store.

KStars Lite is our successful Google Summer of Code project for 2016. It was developed by our star student and active developer Artem Fedoskin who managed within a few months to create a QML/QtQuick lite version of desktop KStars with many features including:

Full Skymap

Sky Map
A beautiful sky map that takes you into deep space to see stars, planets, galaxies, and much more:

  1. All Solar System Objects
  2. Constellation Art
  3. Constellation Boundary Lines, Lines, Names
  4. Equatorial Coordinate System
  5. Horizontal Coordinate System
  6. Deep Sky Objects
  7. Stars and Deep Stars
  8. Ecliptic, Equator and Horizon
  9. Milky Way
  10. Satellites
  11. Supernovae
  12. Labels

GPS-Based Location

While you can select your location from the thousands of cities shipped with KStars Lite, you can also simply ask it to automatically fill that information and it would fetch your location within a few seconds!

This feature is very handy when you're on the field and want to see an accurate representation of the night sky form your current location.

KStars Lite fetches not only longitude and latitude information, but also geographic information about your current location (city, state, country) via Google services.

Color Schemes

Similar to the desktop KStars version, KStars Lite support setting of several color schemes.

Most notable is the Night Vision scheme that enable your eyes to adjust to the darkness while still being able to utilize the sky map fully without any blazing glares that could ruin your night vision.

Projection Systems

Select from various projection systems. A projection system is used to map 3D space into your 2D screen, and there are many ways to do it including:

  1. Lambert azimuthal equal-area projection.
  2. Azimuthal equidistant projection.
  3. Orthographic projection.
  4. Equirectangular projection.
  5. Stereographic projection.
  6. Gnomonic projection.

Find Any Object

KStars Lite provides you with a convenient search functionality to search within KStars catalogs that includes thousands of stars, galaxies, nebulae, and solar system objects. When an object is found, you can go to the object on the sky map or view detailed information about it.

But what if the object is not found within KStars database? Do not worry! KStars include functionality to search numerous online catalogs for millions of objects. Once found, the KStars database downloads the new object data, and includes the new object just like a regular KStars object where you can view its information, center it...etc

Detailed Object Info

Explore detailed object information provided by KStars Lite. This includes images, position and time information, and links to pursue further information on the object.

Want to know when the project will pass overhead? Check the position tab. Want to see more images of the object? Check the links tab. Have some notes to write about the object? Save them in the logs tab.

The general tab includes the most prominent information about an object such as its magnitude, its distance from earth, and its angular size in the sky.

Full INDI Client Support

Control your Telescope, CCD, DSLR, and even your complete observatory within KStars Lite. With its first class INDI client support, you can connect to an INDI server running your equipment, and start controlling them immediately.

You can track your telescope motion on the sky map, and even select any object and ask the telescope to track it. Have a camera attached to your telescope? Simply capture an image and get a live preview on KStars Lite!

No need to fiddle with cables and wires anymore, use KStars Lite to wirelessly control your astronomy equipment at any time and from any where.

What's next?

Please bear in mind this is our first KStars Lite release for Android, and while we worked hard to fix some of the quirks in the development version, there is still room for improvements including improving its stability and performance:

  1. Reduce startup time: Currently it takes about ~35 seconds for KStars Lite to startup (on my Samsung S5) which is a very long time compared to what users typically expect on Android. We will be working hard to reduce this startup time to an acceptable range.
  2. Adjust sky map to follow gyroscopic sensors: We eventually expect users to point their phone/table to any location on the sky, the KStars Lite would then adjust the sky map to show this particular region of the sky. There were several issues with using Qt Sensors that prevented this feature from making it into the initial release, but we are working on it.
  3. Ekos support: We might include some of the modules of Ekos in the Lite release.

Friday, October 28, 2016

KStars 2.7.0 is released

I'm very glad to announce the release of KStars v2.7.0 (Menkab)! This new version brings improvements all over the board, from speed improvements, better cross-platform support, and Android mobile/tablet support is now finally merged into mainline KStars!

Windows & Linux versions are available for download. OSX version should hopefully be available soon.

Here is a short demo made by Artem Fedoskin, our GSoC 2016 student and currently an active developer of KStars:

We are still working on a few minor issues with the KStars Lite for Android before we release it soon on the Google Play Store.

Using KStars on embedded devices such as Raspberry PI provides a much better experience now thanks to order-of-magnitude speedups made by Akarsh Simha that cut some computation cycles by over 50%!

Another important feature is object internet lookup from online catalogs! It is a very exciting feature developed by Akarsh that enables you to find any object whether it exists in KStars catalogs, or any online catalog. Akarsh made a great video to explain how to use this neat feature:

Significant changes were made to improve Ekos GUI. It is now much more compact and accessible, especially on low-resolution displays.

Internally, the guide module was completely rewritten to enable support of multiple external guiders. Now we support lin_guider in addition to PHD2 and of course the internal guider. Performing guiding and autofocusing is now a lot more intuitive since the FITSView is embedded within the module, and not as an external window in prior versions. This streamlines the astrophotography workflow even further and makes monitoring changes quite handy.

The guide drift graphics was rewritten in QCustomPlot and provides many facilities to inspect the data along with zooming and panning support plus the long-request RA/DE legend! Guiding control parameters were updated to provide finer control over the guiding process and can control not only guiding pulse corrections, but also their polarity within each axis.

The alignment module received minor improvements as well, but most importantly, it now detects parity after first capture and reuses this value for future captures. Reusing the parity should cut solving time in half since the solver attempts to search over both positive and negative polarities by default. The overall alignment GUI was made simpler with only options necessary to perform the alignment process remaining while all additional options were moved to the KStars settings.

Focus module also received significant updates! All focus operations are performed from within the embedded FITSView. Furthermore, the user can now select which focus algorithm to utilize to calculate the Half-Flux-Radius (HFR) value. I developed a new gradient-based focusing algorithm in addition to the previous centroid and threshold algorithms. This new algorithm is less susceptible to noise and gives far more accurate HFR values even for donut-shaped stars. It is used by default but the user may change to any algorithm at any time.

In previous versions, each Ekos module supported capture of dark frames, but each module was handling it separately. Furthermore, the dark frames were captured, subtracted, and then discarded. With 2.7.0, a universal dark library was developed whereas dark frames are reused once they are captured. By default, dark frames are reused for 30 days. When any setting that may affect the dark frame validity such as binning, exposure time, temperature..etc is changed, a new dark frame is captured and stored for future use. This is now shared across all modules, so if you take a dark frame in the focus module, it can be used across Ekos.

Additionally, the capture module also received a face-lift and now includes options to specify upload mode and remote directory to save images. This resolved a conflict where one directory was used to save remote and local images. The user may also pause/resume sequences whenever desired.

The following summary is written by our newest development team member: Robert Lancaster. Robert was instrumental in bringing many improvements to the FITSViewer tool and KStars support on Mac OSX.

The KStars FITSViewer and its embedded FITSView have received numerous enhancements with KStars v2.7. First, the FITSView zooming behavior has been refined so that if a point in the image has been selected with a marker or if there is a focus/alignment box in the image, by default it will zoom in or out on that point. If there is not a point selected, the zooming behavior will center on whatever region is currently centered in the FITSView viewport. In addition, for people who have track pads attached to their computer, the pinch gesture has been implemented for zooming in and out on any FITSView. A second useful trackpad gesture that was implemented in any FITSView is the pan gesture, so now you can not only use your trackpad to pinch for zooming in and out, but you can also use it for panning around the image easily. For those who do not have trackpads, clicking to drag the image for FITSViews that are embedded in the FITSViewer was implemented to make it easy to pan around the image.

Another set of additions to the FITSViewer is several overlays that allow you to more easily center objects in the FITSViewer and/or compose your exposure. One overlay, the Cross Hair, gives you a target in the center of your image and two axes, so you can see the horizontal and vertical centerlines of your image. This overlay is extremely important for those who are not using the Align Module to do their telescope alignment so that they can be sure they have centered the star that they are using to sync. A second overlay, the Pixel Grid, gives you a full grid overlay for your image so that you can quickly estimate pixel distances to different points in your image and easily compose your shot. These overlays can be turned on at the same time and will not interfere with each other.

A third major enhancement to the FITSViewer is the addition of several features that make use of the WCS Headers in WCS-enabled FITS files. If you have installed and set the correct path to wcsinfo and have already plate solved an image with your setup, then your images you take with Ekos will have WCS information in them. You can also add WCS Information to an image by using either the online plate solver from or by using the command-line based plate solving routine solve-field. The good news is that the WCS information is loaded in a separate thread so it does not slow down the rest of the program. Once an image with WCS header information in it has been loaded into the FITSViewer, the new WCS based tools will be enabled. The first thing you will notice when you load such a file is that the RA and DEC of your mouse cursor will be displayed in the status bar at the bottom of the FITSViewer. This behavior is not new, but what is new is a feature where you can put your mouse over a deep sky object in your image and a ToolTip should pop up that identifies the object.

If you then right click on the object, you will get a contextual menu that provides options for getting details about the object, downloading sky survey images about the object, centering the object in the Skymap, and even centering the object in a connected telescope. The menu looks extremely similar to the contextual menu that pops up if you right click an object in the Skymap.

There are also several other functions in the FITSViewer toolbar which are useful to WCS enabled images and whose buttons are only enabled when an image containing WCS information is loaded. The first one of these is an overlay plot, which puts an Equatorial Coordinate grid on the image with regularly spaced and labeled gridlines. The second button overlays a set of marker points and labels for all of the deep sky objects identified in your image. A third button will enable a mouse tool that will let you click on any point in your captured image to re-center your telescope on that point. This is extremely useful for framing your deep sky photos

Finally, this new version of KStars provides greatly enhanced support for the Mac OS X platform. While an installer is still in the works, and some bugs are still being worked out, KStars has become fully functional on the Macintosh platform. Several months ago, KStars was very difficult to install on the OS X platform and even when it was successfully installed, numerous features were not working properly. After a successful install procedure was finally hashed out in mid-September 2016, the work of getting all of the bugs identified and worked out could begin. Over the course of the next month, numerous issues were identified, investigated, and in many cases, solved. One of the first issues was getting the icons working since kde icon themes are not supported in OS X. This issue was resolved by bundling the icons.

Another issue was getting, libinidi, and gsc properly built and installed so that the tools used by Ekos could have native support on OS X. The solution here was just to develop a procedure to install them, though on Mac OS Sierra, there may still be an issue installing libindi on some computers. Even so, KStars on OS X could still access remote INDI-servers. By the end of September, KStars was working pretty well on OS X, but it still needed some work. For OS X, the inclusion of pan and pinch gestures in the FITSView/FITSViewer as described above are vital on a computer like a Macbook because the gestures are much easier to use than the scroll-wheel emulation. Once the FITSViewer upgrades were finished in mid-October, work on the KStars OS X bugs could resume. A minor annoyance was that all the windows were independent of one another and thus sometimes, dialog windows could end up lost behind the KStars main window. This was resolved by making many of the KStars windows Tool windows on OS X, except the Ekos Manager, the INDI Device Manager, and the FITSViewer which each received special code to make them stay on top of the other KStars windows. One of the last major bugs in KStars on the OS X platform was the inability to load/use the “Get New Stuff” Download Manager. This feature is very important for downloading images of deep sky objects and different sky catalogs. It was finally resolved in late October by setting some environment variables and launching the KDE program kdeinit5 from within KStars.

While KStars is now fully functional on OS X, it is still being tested and more bugs are likely to be found. It is hoped that in the near future, a simple installer or dmg image file can be developed for a streamlined installation process. But until then, following the instructions should get you a functional KStars installation on OS X.

More OSX screenshots!