Satran Satellite Tracking Antenna

Satran Satellite Tracking Antenna(danaco.se)

41 points by zenbryo 5 years ago | 18 comments

golem14 5 years ago |

Neat! It would be good to know how this is different from Satnogs, e.g., max weight/momentum of antenna, what APIs etc.

Satnogs looks great and is probably more sturdy, but I can't just buy one (no kits afaik), and it is probably more complex to build one.

zenbryo 5 years ago | |

Specs will be released later on since its still in prototyping phase. Satnogs looks sturdy and has a similar control board but seems more complicated. My goal is to offer complete kits for 200USD (shipping and customs not included) but if you can 3D-print the plastic parts yourself you'll more or less cut the price in half.

fotbr 5 years ago |

Wish it had more details: Rate(s) of rotation, load capacities -- including windloading, etc.

Also rather wish it didn't rely on wifi/android, but that's mostly because I don't use anything android based, and don't run any wifi on the home network anymore.

All in all though, it's still a pretty nice looking little az-el rotator. With different control software, it might also be a useful little addition to give your static security camera a bit of extra capability without breaking the bank.

zenbryo 5 years ago | |

Thanks for the feedback! It's still under development so more specs will be released later on.

"Unfortunately" the entire design is based around ESP8266 to make it cheap and easy for people to modify so wifi is the current option but if there's interest for other alternatives, anything is possible.

Since the rotator uses simple HTTP GET queries for the azimuth and elevation, it should be possible to make it compatible with other ethernet enabled positioning software.

fotbr 5 years ago | | |

Regarding other software / platforms, HTTP GET seems easy enough to work with.

My issue with wifi is really just a matter of too-many-networks and interference making it a bad solution for me.

But I understand the appeal of the ESP8266 (and the rest of that family of chips) and don't blame you one bit. IIRC it has a serial port on a couple of pins, so that's another comm option.

In any case, I look forward to seeing your progress. Good luck!

penagwin 5 years ago |

Hmm this appears to be an alt-az mount. If they made a future version as an equitorial mount it would be even better for radioastronamy, and if it's strong enough astrophotography too. They're a lot more complicated though so it's understandable why they didn't go that route.

Especially if this is meant more for geostationary satellites and I'm guessing most satellites like NOAA aren't too bothered by the slightly rougher tracking. Plus I guess the passes are fairly short anyway...

supernova87a 5 years ago | |

I thought equatorial mount is much simpler than Alt-Az for astronomy, hence why the earliest large telescopes used them. All you needed was to align the mount correctly, and then a simple clock can run the movement.

Alt-Az requires a computer to tell the dials where to go at every step of the way and are very non-linear dependent on absolute position on the sky.

Also Alt-Az gives a much more compact design. So as long as you have the computer to control it, isn't Alt-Az preferable?

labcomputer 5 years ago | | |

That’s correct, but equatorial mounts also solve the problem of field rotation on long exposures (which, like the control problem, can be fixed with computers—-just stack short exposures and rotate in software). Field rotation isn’t an issue for radio astronomy, of course.

I’m not sure I would say that equatorial mounts are less compact though.

zenbryo 5 years ago | |

Correct its and "Az-El rotator" intended for amateur radio and was not designed with any other purposes in mind, but this is just the first release. Main objectives were price and simplicity. But I hope to get a good enough response to release other versions in the future, especially a much tougher all-metal weatherproof version.

dbuder 5 years ago | | |

Hey, great product

buescher 5 years ago | |

Just add an equatorial wedge. Search terms: "DIY equatorial wedge"

zenbryo 5 years ago | | |

Thx for the tip! Lots of different upgrades should be available later on and also I hope to build a community of open source designs and addons

benbojangles 5 years ago |

https://github.com/RedBalloonShenanigans/antenny

Rebelgecko 5 years ago |

Cool! I wonder how the pointing accuracy is? When we made something similar for a project that was a big problem with the Az-El servos. Is the microcontroller propagating TLEs itself or is that being done on the controlling device?

zenbryo 5 years ago | |

The accuracy is designed to be approx 1 degree. The current microprocessor code only handles full degrees. But since I hope to get enough traction to afford developing upgrades, using encoders and higher gear ratios could give a higher precision.

The positioning and calculating of TLEs happens in the android app. Hopefully I can also offer drivers for other software like Gpredict later on.

tjohns 5 years ago |

This looks great. It’s so hard to find an inexpensive antenna rotator.

Do you know when the project files will be available to download? I’d love to try making one.

zenbryo 5 years ago | |

These will probably be released at the end of this month I think, just have some tweaking left to do. I'd estimate that all the files take approx 30-40 hours in total to print with 0.4mm nozzle, 0.25mm layer height and 60mm/s main print speed on a standard 3D-printer with a 20x20cm bed.

You can visit my website and leave your email at the very bottom, and you'll get a reminder when I release something or start selling the kits/electronics.