Coming soon, a new Observing Sites page on

I am actively working on… and there is a lot going on behind the scene. One thing is new though: I start to enjoy front-end dev for the first time (you know, the mix of html, javascript and css), thanks to the excellent framework Vue.js.

Coming very soon, a brand new observing sites page! Stay tuned.

Reaching 50% of documentation for SwiftAA

I just reached 50% of documentation for SwiftAA, the best astronomical framework in the  language Swift out there! That’s a small milestone, but I’m happy it’s been reached. Now, I must do the same with Unit Tests, which is as important as the documentation.

You can access it right here:

iObserve 1.6.0 submitted to the AppStore

After many months, I finally managed to submit a new version of iObserve. I am happy to see I continue to be able to improve it (even if I am not writing Objective-C code anymore regularly). I also hope it will be good enough for the coming weeks, as I am preparing more stuff for the future!

Making an auxiliary app about Observing Sites…

… on the road to iObserve 2!  

As you certainly know if you read this blog a bit, here and especially here, I am preparing, slowly, a version 2 of my famous app for astronomers: iObserve. One key thing about it are observatories, over and over again. The problem of managing different places, being able to record your own places, possibly sharing them etc, exists since the inception of the app, when it was only in a widget form… 

In the course of the years, I’ve developed a lot of things about it and never found it entirely satisfactory. Then came was first intended to be the backend for a much lighter iObserve client. But it appears it can solve a lot of things! And the first thing it can solves is to be the one-place-to-go for everything about observatories in the world. 

Hence, one of the primary mission of is to record, store, share, make available all the information about such places.

And the only way to correctly develop, test, bullet-proof the observing sites at is to build an app, using the arcsecond.swift and SwiftAA sdks. So here it is, for the visible part:

Of course, as soon as it gets ready to edit and display useful things about all observatories, and you can add your own etc, you’ll get your hands on it! 



Closing sources of… for now

I’ve decided to close the sources of for now. It’s been quite a while since I started to think about it.

Two main reasons. First, the opening of the sources had strictly none of the expected effects, that is, to gather people around the project, even just a few. None. Second, is a fairly large project, some said too much. And before I find a satisfactory plan of splitting / simplification / whatever, I prefer to make my business on my own.

However, if anyone is interested to really participate, I’ll be happy to include him as a member of the GitHub project.

One small step for a developer…

… but quite a milestone in my master plan (see previous post). After about a year of (discrete periods of intense) work, I’ve decided that SwiftAA, the best collection of astronomical algorithms on Swift, hit the 2.0-alpha stage.

SwiftAA is intended to be the underlying code framework of all scientific computations of the next version of iObserve. With it, I’ll be able to provide tons of details about many objects, and especially about Solar System objects, which are clearly missing in the current app.

It’s an alpha stage, of course. It means a lot of details need to be polished: iOS version polishing, more unit tests, a more consistent handling of numeric types etc. But all of the C++ code is wrapped in Objective-C(++) code, and all that old-style code mimicking the original AA+ one is now « Swifted ». That is, it has been elevated to a lot higher level of expressive formulation.

Complexity remains, since the solar system isn’t quite easy to simplify. Hence, when one has the goal of minimizing the amount of lines of code, to extract the most of it, things aren’t easy to read at first. 

But there is a Swift Playground for those interested to learn. I wish I had more time for making this Playground more « ready to use ». But as for now, you need to dive a bit into the thing and the project to actually understand it. But time will come, I’ll prepare a better one.

In my website stats, I noticed that some people keep talking about iObserve, which is great. One post however mentioned the wish to have a Linux version of it. Those interested in what happens here @ probably understood that it is also part of the master plan. But current web-based technologies to make cross-platforms apps are difficult to put in place. I’ve tried about 6-7 times. But I don’t give up! 

I’ve received about 30 new observatories to be included in the next version of iObserve. That’s really great, as it is the sign of a strong usage of the app (more than 15k downloads so far). They are all in my list of to-dos, but I must say that it is sometimes hard to be motivated to finish this new new version, and I am late. But it will come! 


Master plan of the software department @

Software is amazing, because it let you create your own world. This is the world as I see it in the future. I learned so much by creating iObserve (over the course of the past years…). And as in science, the main lesson was that I didn’t know much actually… 

Hence, since I love challenges, I decided to dive into new questions:

  • new language for the app iObserve
  • new architecture for the app
  • own backend service with specific language
  • start cloud service with storage and online DB
  • extract as many macOS components from app into open-source libraries
  • finally implement dreamed features (night logs, observation simulator…)
  • I’m sure something is missing… 

If someone want to share the bumps ahead on the road, he|she is most welcome.

Clear skies to everyone!

P.S. By the way, just migrated to Python3… 

Le silence est d’or…

Dear iObserve users, not many news over here for some time. iObserve 1.5 is still downloaded quite many times every week (reaching 12.5k total downloads!). I can see that some of you send me new observatories. I’ll find some time to create an update of that bunch of new observatories.

Apart from that, I’ve been able to re-compile and re-run iObserve Touch on an iPad with iOS 9.3. And that’s nice, because it wasn’t so easy with the amount of code involved here and there. So maybe I could find some time for a little update as well. It reached almost 6k downloads by itself, wow!

On the other side, I’m a bit busy with new stuff. Most of which is the decomposition of iObserve code into little frameworks (for instance: But also scientific ones!

In particular, I am preparing a Swift playground with the best astronomical algorithms in town. The code will be good for developers, for iObserve2, but the Playground could be interesting to teachers! Check it out here the on-going work:

Talking about iObserve 2, I continue to develop things in preparation of it. Among which…! And its SDK (I started with Swift, but javascript will also come soon… <hum, hopefully>). I take the occasion to say that is open-source, and you can contribute!

Interestingly, this all-code activity is a kind of rest for me. At my startup job, I spend the day interacting with tons of new people (and it’s really great!). So it’s nice to interact with computers a bit. 🙂 

The master plan of iObserve 2

I’ve read somewhere that good software takes 10 years. Ah yes, here, from someone who knows a fair bit about it. As you have read here, iObserve is 6 years old. And despite recent 1.5 update series (to finally release Sky Maps), the code definitely reaches a level where any true new feature is immediately flooded by the amount of work of refactoring, additional bug fixing, not talking about the weaknesses revealed by the new feature… 

 The new Sky Maps view.
The new Sky Maps view.

But iObserve is a master piece I don’t want to just let go (some people are good at letting it go, at some stage in their life – I trust my fear of getting bored to continue creating lots of stuff…). So I prepare the version 2 of that app. 

To do so, I am working on a collection of great stuff, some of them being mine, some of them inspired by others, or by participating to other projects. Here a list:

Siesta is a great framework to consume REST APIs. It will make the access, download, cache, storage and update of data a looooooot easier than the current code in iObserve 1.

• Of course, iObserve data is of absolute central importance in the app. Nowadays, it is downloaded from the various services with custom connectors for each of them (SIMBAD, ADS, JPL Horizon…). That’s why has been built!

• The is being foreseen to be a whole cloud service by itself. With user accounts and all that stuff. And it will be part of iObserve 2 chain of software. There are periods of time where I put efforts on iObserve itself. And there periods where I put efforts on… Depends on the direction of the wind.

• The scientific part of iObserve is based on Jean Meeus’ textbook ‘Astronomical Algorithms‘. I’ve implemented part of it (available here, but not updated since exactly a year). But a lot more complete implementation has been developed in C++ by P.J. Naughter, called AA+, who let me write a wrapper for it. Thanks to recent efforts, I managed to bring the AA+ library to the Swift playgrounds! Nice to have little Solar Systems under your fingers. I will post example and movies as soon as it is stable. SwiftAA is open-source.

• An additional (and very important) part of scientific calculations is related to dates. Current implementation in iObserve is far from satisfactory. Hence, I’m helping improving the open-source project SwiftDate.

• In addition to that, I am preparing some useful UI components (all open-source) that can be used in pro apps like iObserve: tabs, jump bars, and split panes.

That’s all it takes for the foundations… 

Happy coding!