So here comes another minor release for KStars v2.8.5 just less than two weeks after 2.8.4 was released. KStars v2.8.5 is available for Windows, MacOS, and Linux. In addition to the usual bug-fixing and enhancements, here are a couple of useful features for our users:
1. Log Manager
Users complained over the year that it was hard to get logs for Ekos & INDI to diagnose issues. Due to the complexity of Ekos & INDI, logs are absolutely necessary in order to diagnose any issues. With 2.8.5, it's now super easy to enable logs and they're all in one place. From the Ekos Summary screen, click logs to open the Log Manager and then select which specific Ekos module and/or INDI driver you want to diagnose. Start Ekos as you normally do and then all the logs are stored locally, even if you are using remote INDI drivers!
2. Filter Manager
While users were able to select filter focus offsets in previous version of KStars, it was only applicable in the capture module. Not only that, you were limited to locking a specific filter when running the focus module, but what if you need to lock the filter depending on what current filter is in use? What if you don't need to run autofocus on filter change for all filters, but specific ones? The Filter Manager is here to resolves these issues.
My primary motivation behind this is due to my recent imaging session with IC5070. I wanted to use Luminance filter as the locked filter for both Lum and Hydrogen-Alpha, and when using OIII/SII, I wanted Ekos to keep the current filter and focus with it. With the old system, you were limited to one locked filter for everything, but now it is much more versatile and configurable. Please test away and report any bugs to KDE Bugtracking system.
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!
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 astrometry.net 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 nova.astrometry.net 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 astrometry.net, 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.
Hubble-like super wide field images of galaxiesand nebulae are truly awe inspiring, and while it takes great skills to obtain such images and process them; many notable names in the field of astrophotography employ gear that is notvastlydifferent from yours or mine. I emphasizevastlybecause some do indeed have impressive equipment and dedicated observatories worth tens of the thousands of dollars. Nevertheless, many amateurs can obtain stellar wide-field images by combining smaller images into a single grand mosaic.
M31 3x2 Mosaic in Ekos
We are often limited by our camera+telescope Field of View (FOV). By increasing FOV by means of a focal reducer or a shorter tube, we gain a larger sky coverage at the expense of spatial resolution. At the same time, many attractive wide-field targets span multiple FOVs across the sky. Without any changes to your astrophotography gear, it is possible to create a super mosaic image stitched together from several smaller images. There are two major steps to accomplish a super mosaic image:
Capture multiple images spanning the target with some overlap between images. The overlap is necessary to enable the processing software from aligning and joining the sub-images.
Process the images and stitch them into a super mosaic image.
The 2nd step is handled by image processing applications such as PixInsight, among others, and will not be the topic of discussion here. The first step can be accomplished in Ekos Scheduler where it creates a mosaic suitable for your equipment and in accordance to the desired field of view. Not only Ekos creates the mosaic panels for your target, but it also constructs the corresponding observatory jobs required to capture all the images. This greatly facilitates the logistics of capturing many images with different filters and calibration frames across a wide area of the sky.
Before starting the Mosaic Job Creator in Ekos Scheduler, you need to select a target and a sequence file. The Sequence File contains all the information necessary to capture an image including exposure time, filters, temperature setting...etc. Start the Mosaic Job Creator by clicking on the icon next to the Find button in Ekos Module.
Next, enter the desired number of horizontal and vertical panels (e.g. 2x2, 3x3...etc) and then clickUpdate. The target FOV shall be calculated given the number of panels and your camera's FOV and the mosaic overlap shall be displayed. By default, the percentage of the overlap among images is 5%, but you can change this value to your desired value. You can also move the complete mosaic structure around to fine tune the position of the mosaic panels. When satisfied, clickCreate Jobsand Ekos shall create an observation job and a corresponding customized sequence file for each panel. All the jobs shall be saved to an Ekos Scheduler List (.esl) file that you can load on any suitable observing night and it will pick off where you left. Before starting theMosaic Job Creator, check that all the observation job conditions, constraints, and startup/shutdown procedures are as per your requirements since these settings shall be copied to all the jobs generated by the Mosaic tool.On first use, you need to enter your equipment settings including your telescope focal length in addition to camera's width, height, and pixel dimensions. Finally, you need to enter the rotation of the camera with respect to north, or the position angle. If you don't know this value, start Ekos and slew to to your desired target then use the Align module to solve the image and obtain the position angle.
With Ekos Scheduler, multi-night imaging is greatly facilitated and creating super mosaics has never been so easy. Get started with Ekos now and don't forget to post your results to INDI forums!
In upcoming KStars 2.4.0, due to be released in KDE Application 15.12, astrophotographers will enjoy a new feature that would help them further in framing and visualizing their images: Direct FITS overlay!
Before you use Ekos Align module, make sure to enable both World-Coordinate-System (WCS) and Overlay checkboxes. WCS appends parameters to the captured FITS image to include information on the celestial coordinates, rotation, and scale..etc. Once you perform your first successful alignment, and subsequent images will be scaled and drawn directly on the sky map.
The FITS histogram tool is one of the few tools in KStars that did not receive any significant updates for more than 10+ years. I first wrote it back in 2004 and used a custom painting widget to show the overall shape of the histogram. But with KStars gaining color FITS support a while back, it was necessary to support multi-channel histogram within the viewer.
While the FITSViewer tool, as the name suggests, is not designed for processing of astrophotography images; features such as the histogram and statistics tools are often important for decision-making during the capture process and for quickly inspecting images, and hence they were made available to the end user. The histogram implementation was also quite buggy as it was designed for 8-bit FITS, but now KStars support 8, 16, 32-bit signed integer, 32-bit IEEE floating point, and 64-bit IEEE double precision floating point. The updated implementation now caters to all data types and is smarter about selection of bin widths for each image.
In addition to supporting multi-channel histograms, the GUI was revamped and is now utilizing the amazing QCustomPlot library. At first, I wanted to utilize the KPlotting KDE library, which was authored by our very own Jason Harris, KStars founder back in 2001! But QCustomPlot offers several advantages over KPlotting including user interaction capabilities such as zoom and drag in addition to a host of other features. Furthermore, QCustomPlot is being actively developed while KPlotting hasn't received any noticeable updates in a very long time.
The following is a screenshot of the older histogram implementation:
Over the past couple of weeks, I worked on a new feature in Ekos: Automatic Meridian Flip.
Equatorial mounts flip after crossing the meridian in order to prevent the imaging equipment train from hitting the tripod. With Ekos, you can set an hour angle limit which if exceeded, the mount will be commnded to flip. The mount must begin tracking east of the meridian in order to the meridian flip to be commanded in Ekos.
When commanding a meridian flip, Ekos will suspend the autoguiding process and waits until the mount completes the flip. Once the mount begins tracking again post meridian flip, Ekos will plate-solve and make any necessary slew commands to bring the mount to the exact location it was tracking prior to the flip.
Next, it will automatically capture a frame and select a suitable guide star, performs calibration, and resumes autoguiding. If In-Sequence focuing is enabled, it will also capture and focus a suitable star. It then resumes the capture process form where it left.
All these steps are completely automated and require no user intervention! Watch the video below for a live demo of this feature!
Recently I was finally able to close BUG#305960 where a user requested support for 3D Cube FITS support in KStars. The FITSViewer tool always supported monochrome images since its inception, as this is what most CCD cameras in astronomy use. But single-shot color CCDs and DSLRs' utilization within the astrophotography world kept growing over the last few years.
Now the FITSViewer tool can display any 2D (monochrome) & 3D (color) cube FITS, and while most of the operations in KStars are geared toward single-channel images, the migration to 3 channel support was relatively smooth.
In addition to the 3D cube support, the FITSViewer tool can debayer images captured from color cameras and stored in RAW format with a specific color filter array (CFA).
DSLR users will gladly welcome this feature as they can inspect their color RAW images in color and may adjust the debayer parameters to produce a clear image of their target. Internally, KStars converts the debayerd image to a 3D Cube FITS without changing the RAW data at all. While the user may save the file as a 3D Cube FITS, it is not recommend. In fact, the debayer functionality should only be used to inspect the image, and the RAW image should always be processed under a dedicated astrophtography tool like PixInsight in order to carry out proper calibration procedure before any integration and registration processes.
In addition to DSLRs, the SBIG CCD INDI driver now also supports color CCDs. More INDI CCD drivers will have color support soon.
A lot has changed in the last few months in Ekos, KStars advanced astrophotraphy tool. The powerful builtin sequence queue is more robust now and can support in-sequence autofocusing, autoguiding limits with dither support, and autopark functionality. The astrometry.net based alignment module has been improved to support the online astrometry solver using Web Services, thereby eliminating the need for an offline astrometry solver that requires gigabytes of star indexes in order to solve.
Coupled with an ever improving INDI drivers, Ekos provides users with a complete astrophotography stack in Linux. While the majority of Ekos development takes place indoors with the help of INDI's powerful device simulator, nothing beats on-site testing with all the hardware connected and ready to go. So a couple of days ago, I decided to put Ekos to the test!
Since I live in a heavily light polluted area about 30 KM south of Kuwait City, my friend and I decided to conduct the astrophotography session some 100 KM away northwest of Kuwait in AlSalmy desert. It's a quite desolate desert, but it is more rocky than sandish so that would help a lot in case we get some wind our way. After setting up the equipment (Orion Sirius EON 120mm APO, QSI 583 CCD, Lodestar autoguider, and Moonlite focuser), I performed the initial autofocus routine, followed by plate-solving a frame in order to establish the telescope's actual position in the night sky. Before Ekos alignment module, this process would take anywhere between 10-20 minutes to get the scope properly aligned using 2 or 3 star alignments, and even after that, the GOTO might not be accurate. With Ekos alignment module, GOTO is highly accurate and it increases in accuracy with each subsequent frame captured and solved.
Using Ekos Sequence Queue, I added 4 jobs, each consists of 6x300s exposures in each filter (Hydrogen Alpha, Red, Green, and Blue). Then I used the Guide module to calibrate the guider and start the autoguide process after slewing to NGC6992 and engaging tracking.
After the light frames were completed, flats and darks were taken. The flats were captured using an artificial uniform light source. Due to a temperature of 39 degrees Celsius in the desert (around 8:15 PM), the CCD was only cooled to zero degrees.
The next day I downloaded all the images to my desktop and used PixInsight to process them. PixInsight is a really powerful tool if mastered well, and there is still a lot of learn from this great tool. I ended up with a decent image that was captured and processed 100% in Linux!
Any amateur astronomer must have experienced the woes of aligning their mount. First, your mount has to be aligned with the polar axis. Second, you need to perform an alignment procedure to enable the built-in GOTO firmware to slew and track your objects of choice. Often we are offered to align the mount with 2 or 3 bright stars spread all over the sky which then enables the firmware to build a simple model for the mount errors that it has to correct for when it slews to a target. Also, at this point, the firmware knows where the telescope is looking at in the sky, or so it thinks as we find out below.
While the simple 2 or 3 star alignment is often sufficient for visual observation, it becomes a source of frustration in astrophotography. After slewing to your target, you often have to perform framing to center the actual object within the CCD desired field of view. Once that's done, your mount is now tracking the object, and you can begin to take your photos.
For deep sky astrophotography, you typically have to take multiple long exposures frames and later stack them. The mount tracks the object sidereally (i.e. in RA), but most commercial mounts suffer from manufacturing defects in the worm gears and other parts that makes accurate sidereal tracking difficult. Furthermore, your mount has to be perfectly aligned with the earth polar axis as any deviation will cause tracking errors.
This is where Ekos Alignment module comes into play. Alignment module performs the following:
Highly accurate GOTO.
Determine polar alignment errors.
Ekos Alignment Module
The way it works is by capturing an image of a star field, feeding that image to astrometry.net solver, and getting the central coordinates (RA, DEC) of the image. The solver essentially performs a pattern recognition against a catalog of millions of stars. Once the coordinates are determined, the true pointing of the telescope is known. Often, there is a discrepancy between where the telescope thinks it is looking at and where it is truly pointing. The magnitude of this discrepancy can range from a few arcminutes to a couple of degrees. Ekos can then correct the discrepancy by either syncing to the new coordinates, or by slewing the mount to the desired target originally requested.
Furthermore, Ekos can measure the misalignment in the polar axix by taking a couple of images near the meridian and east/west of the meridian. This will enable the user to adjust the mount until the misalignment is minimized.
With the addition of the alignment module, Ekos is now the ultimate astrophotographer tool under Linux!
Last week, I attempted to capture an image for the beautiful galaxy pair M81 & M82 in the constellation of Ursa Major. Since I live in a heavily light polluted city in Kuwait, I knew that broadband imaging is quite challenging, and was quite shocked when I found out that the background level due to light pollution noise cuts half the dynamic range of the CCD!
So even after processing, I ended up with a quite poor image:
So I decided to pick my gear, and head to AlSalmy, which is an isolated desert area northwest of Kuwait. While the skies there are not as dark as I'd like it to be, it's the best thing we have in Kuwait, for the time being at least as I'm pretty sure light pollution will ruin it within a decade or less. The trip was well worth the effort, and despite a waxing gibbous moon that lured close to the zenith, the background noise was substantially better than the inner city, no surprises here.
Here is the final image, taken with Ekos, and processed with PixInsight.
