As for why we don't support adding optics between the phone and the sky, there are a few reasons. The accuracy from phone's camera lens is good enough, and we don't want to introduce complexity. The plate solving algorithm also benefits heavily from knowing the field of view, which you get from phone's built in camera but need user input for custom optics. Finally, supporting smaller field of view means shipping a much larger star database which most users won't use, so it's just a waste of storage and bandwidth. Not to mention blind solving a small FoV would be very slow and not work interactively.

For alignment, we support two alignment methods. You can align it like a finderscope, i.e. aim your telescope at a distant treetop and drag the crosshair over it. Once you begin observing, you can also sync to the object, which should give you better accuracy.

As an amateur astronomer living in New York City, finding objects in the night sky has always been a huge challenge. I thought about using the smartphone's gyroscope and magnetometer, but the accuracy left a lot to be desired.

Then I learned about plate solving: given a picture of the sky, we can determine exactly where in the sky the camera was pointing by identifying the star pattern. This was a much better fit - as long as the phone and the optics are rigidly connected, we can repeatedly photograph the sky and determine the pointing direction with very high accuracy.

A lot of work was done to design an algorithm that works reliably with smartphone cameras, which have limited light sensitivity and wider field of view which includes buildings and trees. I experimented a lot with machine learning, and to my surprise, traditional CV methods actually performed better at extracting stars from the image.

The result is AstroHelm, an iOS and Android app that helps figure out where your telescope or camera is pointing, and guides you to the object of your choice. Just follow an arrow on screen, and the object will land right in your eyepiece or viewfinder. Everything happens on device, and no internet connection is required.

AstroHelm is free to use and comes with beginner-friendly objects selected for each night. Optional one time purchases unlock more objects and advanced features, such as interoperability with other astronomy software. I am also proud to partner with astronomy clubs and organizations to offer free licenses for outreach.

I hope AstroHelm can make it a little easier to discover the wonders of the night sky, and I look forward to your feedback!

Comments URL: https://news.ycombinator.com/item?id=49954015

Points: 100

# Comments: 31

Those ladies may be part of the elite now. But remember their parents or grandparents went through the Great Chinese Famine where an estimated 15-60 million people died.

Chinese government actively shapes the online discourse, so the messaging is already filtered. To make it worse, it meant people found out that the easiest way to silence your opponent is to brand them as anti-China, so you see a lot of pro-China virtue signaling. Finally, people also realized patriotism is lucrative.

All the authors observations ring true, and they all stem from one simple fact: China was a very poor country just forty years ago, and even today is only a middle income country.

The uncomfortable truth is a lot of the things westerners take for granted are, in fact, luxuries. Arts and creativity is a luxury. Freedom to pursue passion is a luxury. Compassion is a luxury. Self-esteem is a luxury. If you barely have enough food to feed your family, as a significant number of Chinese people were in the 60s and 70s, you cannot afford any of these.

China has grown richer at a remarkable rate, but the mentality shift can take generations.