A tiny bite of Deep Sky

After rediscovering Siril, a nice astronomical images preprocessing tool for GNU/Linux, I wanted to give another try at processing a few test images taken this summer.

It’s surely not a masterpieces, but I’m not too disappointed either by what I could make of them, given that it was just a basic attempt, with no more than half hour total shoot time.

Postrocessing was done using DarkTable.

SkyPlanner Updates

It’s been a long time since I last wrote about SkyPlanner development, but I still kept working on it, enabling lots of new features.
The Telescopes page has been redesigned to include also eyepieces and barlow/focal reduces, and therefore has also been renamed to “Optical Instruments” in your settings menu.

[cml_media_alt id='578']Instruments Page[/cml_media_alt]
Instruments Page

Adding at least a telescope and an eyepiece will show a new panel in the session pages, with all possible combinations, calculating magnification and field of view.
It will also add a new menu when clicking on a DSS preview image, that will show you field of view circles overlay.

[cml_media_alt id='580']Field of View Menu[/cml_media_alt]
Field of View Menu
[cml_media_alt id='579']Field of View Overlay[/cml_media_alt]
Field of View Overlay

Filters have been heavly improved. We have now lots of new filters, and the existing ones were redesigned to offer a better experience.

Now you can filter by object type, by magnitude, time of transit, altitude, constellation, previously observed objects, angular size, catalogue. Filters are available both in the main objects list and in the “Suggested Objects” panel, allowing you to fine tune SkyPlanner suggestions for planning your stargazing night.

The “Suggested Objects” list can now be sorted also by magnitude and time.

A new interesting feature is the post-session report: when reviewing a past session, you can mark as observer each object in your list.

After doing so, a “report” button will appear for that object, allowing you to write an extended description of your observation.

Finally, clicking the “Report” button on the top toolbar will display your report almost ready to be printed. You may wish to click the “Write report” button to write some notes about the whole session, instead of single objects.

Additionally, you can share your report. By default this is disabled, but clicking the “Share” button will make it publicly available.

You can share it with a few options: first, a web address, that you can embedd on your blog/website, or send via email. But you can also one of the predefined buttons for social sharing, on Google+, Facebook, Twitter.

But sharing is now enabled also for the regular session planning: in the “preview with images” section of a planned session you’ll see the same “Share” button.

Lastly, there were a few additions to the objects catalogues, most notably the Barnard catalogue of dark objects.

These were just a few highlights, to find out more just go to SkyPlanner home page and try it.

SkyPlanner Source Code

I’ve been long waiting for sharing SkyPlanner source code in a public repository.

Problem is, I had to fix a few copyright headers, cleanup some stuff, and, you know, laziness.

Now I finally published them on my bitbucket account: https://bitbucket.org/gulinux/skyplanner and also on GitHub: https://github.com/GuLinux/SkyPlanner.
It’s still missing a README file for compiling and all, but if someone is curious about how SkyPlanner works, this is a huge start for poking it.

Happy hacking!

C++11 and RAII with old C-style API

When programming in C++ it can often happen to be using C-style API.
These usually come in the form:

where the return value is never a real output value, but instead an exit code, and usually 0 means success.

To handle such API in a sequence of operations, one is then usually blinded to do something like this:

and so on, which is kinda boring when you have to call lots of API functions in one method.

I have been trying to write some kind of wrapper that can help making this a bit easier.
In a real life example, I’ve been trying to use gphoto2 api in a c++11 application.
Using c++11 lambdas and RAII this is what I’ve been able to do:

I can then declare some variables in the first part of the method, and inside the “gp_api” block i can execute a sequence of operation, each one returning an int value. This value is automatically checked for an error, and if it it’s a success exit code, the next sequence block is executed.
run_last is finally executed if all steps are completed successfully. An optional mutex locker (QMutexLocker) is passed to the gp_api block as the last constructor argument, to automatically lock the c api for multithreading.

How have I accomplished this?

This is the main class so far:

The sequence class accepts a list of runs as construction parameters. These are stored as a class field, and sequentially executed at class destruction.
Sequence is a template class: you can define the return value type, the success value, a comparison operator to check each function result code against the success value, and finally a generic RAII_Object, which can be as previously told a mutex locker, or some other kind of resource to unlock after API executions.

The define directive at the end of the code is used to automatically create a run object which already contains a description of the code being executed (stringified).
You get this description in the on_error callback.

Near my gphoto class I also added a typedef to conveniently call the proper sequence template class with correct template parameters:

Which means that gp_api accepts code blocks returning int values, that the “ok” value is GP_OK (0), and that the returned value must be equal or greater than GP_OK to be considered a success run.
It also accepts a QMutexLocker shared pointer for thread locking.
As you can see in my first example I didn’t assign the gp_api object to any variable; this means that it is immediatly created, executed and destructed, for synchronous run.

So this is a simplified usage example:

High Resolution Moon Mosaic

A shot at the moon taken in a last quarter evening.
It’s a mosaic of 78 pictures, each of them stacked from 300 frames of 500. Images were taken at primary focus of my Meade ACF 8″ (2000 mm focal length), using a QHY5II-L mono.

Seeing was a bit too bad (I have to shoot from my window, since I don’t have a garden, which can make turbulence even worse).
Even if it’s not a perfect result I’m pretty satisfied: given the conditions lots of details are visible, and it also look quite good.
I hope to be able to shoot something even better soon :)

SkyPlanner

In the last few months I started again deditcating more time on astronomy and star gazing.

To better organize my star gazing sessions I started developing a software capable of suggesting celestial object from various catalogues, choosing them among the best visible ones for the selected date and place, and that’s how SkyPlanner got started.

SkyPlanner has many features useful for visual observations: it allows searching and even suggests many objects from many catalogues, such as Messier, NGC/IC, Abell, Arp, MCG, UGC; provides information about the star gazing session, for instance weather, sun and moon rise/set time, moon phase; allows you to set your own telescopes, automatically estimating each object difficulty for the selected instrument; downloads preview images of the object field from the Digitized Sky Survey Archive, presents additional catalogue information and allows you to set your own notes before and after the visual observation.

The objects list is automatically sorted by transit time, creating a printer-friendly star gazing schedule.

I hope this software will help many of you organizing your best star gazing sessions!

I’m open for suggestions, feedback and error reporting, both in my blog here, or through  SkyPlanner feedback form page. A more detailed features list and review is in this page.

A special thanks to Alessia, who helped in many ways, providing suggestions, ideas, testing, writing some catalogues importers, and a very detailed review.

Happy star gazing!

Touché 0.3 Released

Another couple of weeks, another major release!

This time with more interesting features I hope.
First of all, now Touché is a KDE only application, no more dual releases with Qt-only version. Of course, this may disappoint someone, but this allowed me to add some nice new features, like Global Shortcuts for profile switching.
And profiles themself were improved too, both fixing small problems, and adding a “Default” profile, when no other profile is available.
Default profile will also provide a “fallback action” if some key is not configured on the selected profile, this way you can enable an action on multiple profiles without having to copy it.

Main menu was refactored a bit, It’s nicer and much more well organized.

Code was refactored as well, which lead us to an API for adding new “device modules”, not just HID devices.

And we have a living example too: Wiimote support. You can easly setup a Wiimote as remote control by just enabling it in the “Configure Touché” menu entry, “Modules section”, then by just connecting it. Currently it supports every physical button on the wiimote; I plan to add some other nice stuff too as gestures.

As usual, source tarball is available on github download page.
More downloads and information in Touché Homepage