Receiving weather satellite images
2025-11-02
I wanted to build my own satellite dish to receive GOES weather satellite imagery. This satellite is in geostationary orbit, so the signal is much weaker. I am targetting the HRIT linearly polarized signal at 1694.1MHZ. I went to the dollar store and bought an umbrella for 6 dollars. WTF they should just call it the 6 dollar store now… Anyways we love inflation and greed and overpaying for everything.
Took it apart. I removed the plastic by cutting out the plastic endcap. I used a hacksaw and some brute force to get rid of that pin. Then the entire plastic came off and some other parts. I also removed the spring for auto extend because I will just manually extend it. Quite a beefy spring too, can use it for future projects.
Next I bought a wood dowel 3/8 In. x 48 In. This will replace the aluminum rod in the middle. We want this rod to be non conductive or else it will interfere with the feed, messing up the radiation pattern and increase SWR. To remove the existing metal rod, there is a pin near the top. Use a screw and hammer, I smacked that out of the hole, then the whole assembly slid right off. Drilled a 1/16 In hole in the side of the dowel, roughtly 10In from the top, slid the assembly over, and hammered the pin in place to hold the umbrella back together.
I got myself a L bracket I found in my parts bin, drilled 2 holes, and used a wood screw into base of the rod, other side secured to my tripod using 1/4In nut.
Went on Amazon and bought a 47in(1.2m) x 98ft roll of 1.25mm aperture steel mesh. This dish is around 1.3m in diameter, so this should work. I didn’t want to stitch anything because I have no clue what I am doing. I just put the umbrella upside down in the vice, then hot glued the mesh into the metal frame, making sure to pull to remove the slack. The end result wasn’t a perfect circle, but it doesn’t matter, as long as it folds down and reflects radio waves. I also could have used alunimum foil or tape, but that wasn’t a long term solution and I would probably have to retape it every couple times.
I wanted to make a cantenna feed. I went around my neighbourhood and found so many 100mm cans. Unfortunately, the TE11 cutoff is around 1700MHZ, slightly too high. I tried it anyway. With a roughly 44mm feed and soldered to case ~44mm(1/4 wavelength at 1694MHZ) from back reflector, I get no response at target. If I isolate the RF ground from the can, I get great SWR(1.1), S11 of ~-20DB. I tried using this, but it didn’t work. I wasn’t able to receive GOES, likely due to the case not being connected to RF ground, which messed with the radiation pattern and dish illumination.
Because I couldn’t find any cans >100m easily and the cans I found online were way too big >150mm, I just 3d printed one real quick. For this design, the feed was positioned 1/2 wavelength(88mm) from back feed. The RF ground connected via aluminum foil and screws to the SMA connector. This gave me great performance on the VNA. 1.08SWR, -26DB s11. Ok great, slapped this on the dish and it actually worked!!!
2025-11-23
Roughly messing with the position and the focal point, I found that around 20cm depth, the focal point of my ~1.2m dish was around 50cm. I received a very weak signal, 0.4dB, which actually dropped way down to 0.1dB, where I got unrecoverable CRC errors. From my QTH, I can only receive GOES-WEST(GOES18), which is around 30 degrees in elevation. These were some images I got on my first attempt:
Will try in a couple more days to see what I can do. Also make sure to turn off your laptop fans!!! They make to much interference at 1694MHZ!!! I spent hours trying to pinpoint the src, wrapping everything in alunimum foil. Turned off the laptop fan and boom, no more noise…