search

gut-space / satnogs

The goal of this project is to create a functional satellite ground station, able to receive VHF transmissions from NOAA sats and more!
https://aquarius.klub.com.pl
MIT License
10 stars 0 forks source link

Choose the right antenna #9

Closed fivitti closed 4 years ago

fivitti commented 4 years ago

Ok, we also need to pick the right antenna. Currently I know nothing about antennas.

It seems reasonable to start with a fixed, non-moving omnidirectional antenna.

The goal of this ticket is to determine which antenna we want to buy and where to buy it, so shipment to Poland doesn't take ages or is not too complicated.

Originally posted in #2 by Tomek Mrugalski at 2019-09-15T13:31:45.522Z

fivitti commented 4 years ago

@ewe, can we close this one?

Originally posted by Tomek Mrugalski at 2019-11-09T08:25:16.424Z

fivitti commented 4 years ago

Ok, we can probably close this one. @thomson went on a shopping spree and bought Pi 4B model with 4GB RAM. The box has been installed like two weeks ago and seems to be working fine. It comes with an official USB-C power supply that provides very stable operation.

Originally posted by Tomek Mrugalski at 2019-11-09T08:24:07.656Z

fivitti commented 4 years ago

mentioned in issue #16

Originally posted by Tomek Mrugalski at 2019-11-09T08:39:10.990Z

fivitti commented 4 years ago

closed

Originally posted by Ewelina Omernik at 2019-11-09T20:42:27.900Z

fivitti commented 4 years ago

Have you looked at the following:

While the wifi is not being used now, I can see it being very useful during tests (when it's deployed on my balcony). I haven't figured out how to put the cable from inside my flat to balcony. I have only a power outlet outside, not an Ethernet.

Originally posted by Tomek Mrugalski at 2019-10-22T13:15:23.559Z

fivitti commented 4 years ago

We decided to start with RPI 2 B+. If it will be insufficient then we upgrade them.

Originally posted by Sławek Figiel at 2019-10-12T12:51:52.765Z

fivitti commented 4 years ago

added ~2 label

Originally posted by Tomek Mrugalski at 2019-10-01T21:58:49.973Z

fivitti commented 4 years ago

assigned to @ewe

Originally posted by Tomek Mrugalski at 2019-10-22T09:57:34.081Z

fivitti commented 4 years ago

changed the description

Originally posted by Tomek Mrugalski at 2019-10-20T18:25:40.158Z

fivitti commented 4 years ago

Is it even possible to still buy RPi2? Looked at couple random stores in Poland and couldn't find anything older than 3B. Haven't looked too deep, though.

Originally posted by Tomek Mrugalski at 2019-10-22T13:11:18.363Z

fivitti commented 4 years ago

added ~1 label

Originally posted by Tomek Mrugalski at 2019-10-01T21:58:29.427Z

fivitti commented 4 years ago

From Satnogs Wiki:

The Raspberry Pi (version 3 and 4) is the reference platform for SatNOGS (see our Ansible guide to install SatNOGS on other Linux machines). You can try using various distributions for this (eg. Arch, Fedora), but the one we suggest is our custom image based on latest Raspbian.

The main difference between Raspberry Pi 2B and 3 is more efficient processor. Pinout is in general the same. I think that we can start with RPi 2 and update it if necessary.

Originally posted by Sławek Figiel at 2019-09-15T17:24:20.763Z

fivitti commented 4 years ago

RPi2 has a lower performance (CPU) and there is no build-in BT or WiFi (not needed anyway). I think that's enough for our needs.

Originally posted by Ewelina Omernik at 2019-10-12T23:01:38.715Z

fivitti commented 4 years ago

RPi models comparison

I found a helpful comparison of RPi models.

Power supply

how to power a RPi? We want to put it on the roof. What are we going to do if power is not available there? PoE options?

You can read about power here.

USB:

GPIO:

Ethernet:

I think we should use a micro-usb. We can connect a charger or powerbank.

Processing power

how much processing power do we need? My understanding is that every element in gnu radio pipeline adds computational complexity.

I can't find much info. From GNU Radio FAQ:

Hardware requirements basically depend on what you want to do. A modern PC/laptop computer is usually up to most tasks such as receiving broadcast signals, doing audio frequency processing, and many narrowband digital signals.

A modern PC/laptop.

So I think we should use the best RPi we can. In the above comparison we can see that RPis with four cores and at least 1GB RAM are the following:

Potential Expansions

what are the potential expansions that we may be interested in?

I think it's Wi-Fi module (but we can also buy a Wi-Fi USB adapter). RPis with built-in both Wi-FI and Ethernet:

Costs

what's the financial tradeoff? How much more does 4B costs vs 3B vs 2?

I checked the prices in Botland:

Originally posted by Ewelina Omernik at 2019-10-22T22:35:07.103Z

fivitti commented 4 years ago

@ewe any comments on RPi selection?

Satnogs page says RPi3 and 4 are a reference platform. One difference between 3 and 4 is that 4 uses USB-C for power.

Originally posted by Tomek Mrugalski at 2019-10-05T12:38:47.337Z