Receiving GOES Weather Satellite HRIT with an SDRplay and 2.4 GHz WiFi Grid Antenna
Over on the SDRplay forums member RSP2user has posted a new tutorial, this time showing how to receive weather satellite images from GOES satellites with an RSP2 and cheap 2.4 GHz WiFi grid antenna.
GOES 15/16/17 are geosynchronous weather satellites that beam back high resolution weather images and data. In particular they send beautiful high resolution 'full disk' images which show one side of the entire earth. As the satellites are in geosynchronous orbit, they are quite a bit further away from the earth. So compared to the more easily receivable low earth orbit satellites such as the NOAA APT and Meteor M2 LRPT satellites, a dish antenna, good LNA and possibly a filter is required to receive them. However fortunately, as they are in a geosynchronous orbit, the satellite is in the same position in the sky all the time, so no tracking hardware is required.
In the tutorial RSP2user notes that he's been using a $16 2.4 GHz WiFi grid dish antenna and the NooElec SAWbird LNA. In the past we've also seen GOES reception from Pieter Noordhuis who used a 1.9 GHz grid antenna from L-Com which seems to be a better match to the 1.7 GHz GOES frequency. However, 2.4 GHz WiFi grid antennas are much more common and therefore much cheaper. In the past there has been debate on whether or not these cheaper WiFi antennas would be good enough for GOES, so it's good to see that the cheaper option is confirmed to work, at least for the satellite elevations found in the RSP2user's part of the USA.
The SAWBird is a 1.7 GHz LNA which is required to improve SNR by reducing system noise figure, and to filter any interfering out of band signals. The SAWbird is currently not available for public sale, but NooElec have noted that it is due to be released soon. RSP2user also notes that the polarization of the dish is important, so the dish may need to be rotated, and also that flipping the secondary reflector significantly increases the gain at 1.69 GHz.
For software the XRIT demodulator from USA-Satcom for a small fee is used together with the SDRplay RSP2. As seen by Pieter Noordhuis' results, it's also possible to receive these signals with an RTL-SDR and Pieters free software. So it may be possible to reduce the costs of a GOES reception system by using an RTL-SDR, SAWBird and 2.4 GHZ WiFi grid antenna. With those components the total cost would be well under $100.
As a bonus, in later posts on his forum thread, RSP2user shows that the system can also be used to receive HRPT images from the low earth orbit NOAA 19 satellite by hand tracking the antenna as the satellite passes over.
$16? Have you seen the price now?
I think too many of you have been buying these dishes 😀
I have my k5gna dish and aidc3733 (unmodified) from AO-40. Has anyone tried that setup?
Is it just me, or does the picture show the feedhorn reflector installed backward?
You are correct. According to the article, the secondary reflector is purposefully installed flipped over in order to improve reception at 1.6941 GHz as opposed to the original configuration intended for 2.4 GHz operation.
Is this on the regular 2.4 grid antenna? or is it the L band antenna
Actually it is flipped over to make the signal less bad…the dish is for 2.4 GHz. Two modifications that help a great deal is lengthen the dipoles to 43 mm (from 31, probably the single-best improvement you could do) and move the reflector back one inch (2.5 cm) so the signal doesn’t cancel. At the stock location for the reflector, the signal for 1.7 GHz is out of phase.
Hey, Is there any reson for the rotation of your antenna or is that just so it does not fall over? Also if you hook up your SDR to a raspberry pi and run spyserver you can connect to it with SDR# over your home network or you can port forward port 5555 and connect to it anywhere in the world.
The rotation angle of the grid reflector and receiving element is the skew angle relative to the vertical polarization of the satellite transmitted signal based on the actual position of the receiver on the Earth’s surface. You can use the online application at http://www.dishpointer.com to find the position of the GOES satellite relative to your position on the Earth as well as the skew angle for the rotation of the antenna.
There is no skew angle. GOES is circularly polarized. He’s taking a -3db hit with that design, not accounting for the frequency mismatch, which makes it worse. It’s great that it works though!
Are you saying that I can use a modified 2.4GHz antenna and point it at the right point in the sky without skew and I’ll still be able to receive the signal perfectly well?
Because that would save me quite some effort, my current tripod doesn’t have the skew adjustability.
Harry – Depending on your location in the continental U.S., the skew angle can be relevant in addition to the polarization angle. Some brands of the 2.4 GHz 1 meter grid parabolic antenna, such as the Premiertech ANT-GRID-24DBI, have been modified by users to work reasonably well at 1.6941 GHz for receiving the linearly polarized HRIT signal from GOES satellites. To answer your question, a number of people have been successful at using modified 1 meter 2.4GHz grid parabolic antennas to receive GOES HRIT signals by pointing the antenna at the right place in the sky using the proper skew angle for their location. Where to point the antenna and the skew angle for your location can be found here: https://www.dishpointer.com/ . The tripod does not need skew angle capability. It only needs to provide a vertical mounting post. The mounting hardware for the GRID-ANT-24DBI, for example, allows for 8 adjustments (45 degrees at a time) in skew angle rotation in addition to elevation and azimuth adjustments when mounted to a vertical post.
The GOES HRIT signal is linearly polarized. The post was about receiving the linearly polarized GOES HRIT signal, not the circularly polarized GRB signal.
But GOES-17 transmits RHCP HRIT signal.
“Another Passer by” please take time to do some basic research. The GOES 16 and 17 HRIT signals are transmitted using linear vertical polarization. Do a Google search on “HRIT/EMWIN – National Weather Service – NOAA vertical polarization” and open the pdf file from NOAA labeled HRIT/EMWIN – National Weather Service – NOAA. On p.16 you will find the specification form NOAA stating that the HRIT signal uses linear vertical polarization.
I respectfully disagree. RG-6 is dirt cheap and is the type of cable that is used for satellite and cable TV installations. It is swept tested for 3 ghz. A 50 foot run loses about 4.5 db. A sawbird LNA / filter at the dish gives 30 db gain and the dish itself another 20 to 25 db depending on the size of the dish. There will be a slight loss because of impedance mismatch but the SWR is only 1.5:1
i will be running coax for around 30 ft. what kind of coax is suggested thanks
Dont. Lna and sdr should be at antenna, then use active usb 3.0 wire to your shack. Or even better convert usb to ethernet wire to the shack. It u must try coax goes woth lmr400 from times microwave. 1.7ghz losses are bad in coax
Just bought all my stuff, including a very veeeeeery cheap 2.4 ghz antenna, I got it for 13USD. I hope it works!!!!
hey there, did you receive any hrit with that cheap wifi antenna? I’m curious
Not yet, Im waiting for my Sawbird and Nooelec SDR Dongle, I will let you know!!!
What about now? 🙂
I just got one for €30 delivered home. I’m going to try receiving METEOSAT-11, it’s the European variant to GOES. Uses same frequencies.
So how did your project end up?
This is awesome! I was waiting to see the thought emporium video to see if they can receive goes satellite with their wifi grid antenna, they probably will because they are using the same antenna (or a very simillar one). Now that I know it works, It’s on my “cool stuff to do in the future” list. Good news! Great!