How to Receive Images from VHF Satellites
Hi, have you ever thought about something as random as “what satellites are passing over my head?”
If you look into it, you’ll discover a type of satellite that sends cool and useful pictures from space. However, receiving images from these satellites often requires a satellite dish, a custom LNB (Low Noise Block), and manual tracking (or an automated rotator, which can be built or bought). Fortunately, there are also VHF (137 MHz) satellites that send images to us here on Earth, and they are much easier to receive. Currently, there are five active satellites in this frequency range that are operational:
Active Satellites
- 🇺🇸 NOAA 15: 137.620 MHz
- 🇺🇸 NOAA 18: 137.9125 MHz
- 🇺🇸 NOAA 19: 137.1 MHz
- 🇷🇺 Meteor M2-3: 137.9 MHz
- 🇷🇺 Meteor M2-4: 137.9 MHz
These satellites are easy to receive and, most importantly, are free to use—they are unencrypted and meant for geeks like us, to play around with. So let’s start.
What do you need?
- VHF Radio
- Antenna tuned for 137 MHz
- Computer
Yes, these are the only things required to receive these satellite images. So let’s talk about them individually.
Receiver
To make your life easier and even make it automatable, I highly recommend an SDR radio. The most popular and cheapest is an RTLSDR Blog. But be careful, because there are a lot of clones, so do not get scammed!
You can also use a handheld VHF radio, but you would only be able to receive NOAA satellites (more on that later). So I will be primarily talking about using an SDR radio.
Antenna
One of the best antennas that I know of and I have is a QFH antenna. It is a spiral rotated to match the circular polarization of the signal coming from the satellite.
But you can also use a V-Dipole antenna.
Computer
Obviously, you will need something to decode and display the images captured somewhere. And for that, you can use a really good piece of software called Satdump.
It has built-in decoders for all kinds of satellites (including our VHF sats), it can track, view, record, decode, basically everything related to satellite shenanigans.
The Process
So, how does the process work? Here’s the step-by-step guide:
-
Track the Satellite
There are a lot of applications/websites that make this process easy. One of my favorites is a website called n2yo.com.
It has loads of satellites, including our VHF meteor satellites. You can also use Satdump, but N2YO is simpler to use. Once you find the time of the pass, set your radio to that frequency. -
Set Frequency
For example, if there is a NOAA 15 pass, you will want to receive on frequency 137.620 MHz FM. -
Record the Signal
Once you start hearing sounds, record them!
After recording, transfer the signal to a computer. -
Process the Signal
To process the signal, you will use Satdump. There are a lot of tutorials showing how to use Satdump, so I won’t go into too much detail here. -
Get Your Image
After processing, you should have a working image! 🎉
Quick Recap
- Track the satellite (use N2YO or Satdump)
- Tune your radio to the satellite’s frequency
- Record the audio signal
- Process the signal using Satdump
- Enjoy your satellite image!
That’s all for now. I hope you enjoy experimenting with VHF satellites as much as I have!