Seeing Satellites With The Discovery Drive

追加: 2026-05-09

[00:00:00]Hi, and welcome back to the Save it for Parts channel, where today we are moving ahead with some of my radio astronomy experiments. Now, in the past, I've looked at satellite signals using miniature radio telescopes, usually hacked TV dishes, and I would like to graduate into looking at natural features out in space. Now, I still don't 100% understand all of the ways to go about doing that, so I'm slowly developing my skills using more of the satellite microwave imaging stuff that we've done before. I have several videos where I've done that. I've used a little RV dish as a microwave imager to scan the sky in usually the KU band, the commercial television satellite band, and just show me hot spots, which in those cases are KU band satellites. Now, I'd like to do this with some other frequency ranges, and I have a bunch of feeds that go on a Discovery dish, including one for natural radio astronomy for the neutral hydrogen frequency, but that's a little more complicated because I think I need longer integration times. Basically, I need to aim the dish at one point in the sky for several minutes to get a good signal because the neutral hydrogen line clouds of gas out in space are very, very faint signals. So, you can't really pick up the signal from those in just a fraction of a second the way you can with an artificial satellite. So, we are going to start again with artificial satellites using some of my newest motorized scanning systems, the Discovery Drive that goes with the Discovery dish and some other antennas.

[00:01:30]And then, if we have time, we're going to look at the big motorized dish out at Sandland that I have been calling the Sandland Radio Observatory. That's in the 18-ft geodesic radar dome that we got from a real radio observatory up in Canada, and the idea there is to scan clouds of hydrogen in the sky, stars, pulsars, all kinds of stuff, but that's kind of in the future. Like I said, I'm still developing my skills in that direction. I'm still learning. I'm still building on my past experience a little bit at a time so that I can work my way up to the big interesting science stuff.

[00:02:04]So, I've really been enjoying the Discovery Drive from KrakenRF. They sent me a prototype while back, and this prototype has a couple issues, but they are now releasing the commercial version, and if you want to buy one for yourself, I'll put some links down in the description. I do have an entire review on this, too. So, if you're interested in knowing how it works, uh you can check out that video. And I do have other antennas, like you can see some around me here. I've got a hacked RV dish that I use quite a bit. I've got some commercial dishes that have azimuth-elevation motor tracking, but not all these work very well for everything I want to do, and the Discovery Drive here is actually closer to the big motorized dish out at Sandland, at least in how you interface with it using the rotor control software or package for Linux, and um yeah, it's it's basically just a nice test version for what I want to do, and it's a really nice antenna system. You can put different things on it. You can put the Discovery dish on here. You can put like an arrow antenna on here, which is what I have now, so very flexible.

[00:03:03]A little bit more expensive than some of the dumpster dived options that I have, but yeah, as far as a consumer grade rotor system, it's one of the most affordable ones out there. And as usual for these videos, I'm out here running all my code from a laptop stacked on some buckets.

[00:03:18]Um you might be asking, why don't I have a ham shack? Didn't I set up a ham shack in a prior video inside the garage? And yes, I did, but for one, I don't have all the wiring run down to it yet. I still need to drill some holes in the wall. And number two, I like to be able to see what the actual hardware is doing, and I do have a security camera up there, but it's a little bit easier to run the code here and then just turn around and see what is actually happening with the antenna. Is it face-planting onto the roof? Is it falling apart? Is it slamming the antenna into something it shouldn't? And then I can just pull plugs if I need to.

[00:03:51]So, it is still more convenient to field test things in the field outside like this. All right, I'm trying to run my code, and I'm already having some issues with mismatching variable types. That's fairly expected with my level of coding skill. So, I went to college for computer science. I have a bachelor's degree in computer science, and I actually have a master's degree in computer science, and I'm terrible at programming. That's probably why instead of working for a AI or IT company these days, I'm sitting here at my laptop between the compost bin and the barbecue hacking satellite dishes. So, what should be happening here is that the dish basically sweeps back and forth across the sky and uh records the signal strength at each position. I wrote this for another antenna, actually one of my hacked RV dishes before um with different motors, so we might have to change some timings or put in a delay here or something. Okay, so that's what the southern sky looks like, or at least a small portion of the southern sky in 401 MHz. There is some sort of signal source down on the lower right, and that's about where my house is, so that makes sense. There's probably something in the house putting off um some radio frequency interference around 400 MHz, and the rest of the sky is fairly uniform, just background static essentially. Again, this is just a very abbreviated range of the sky, so each pixel is 1 degree, so this is a very low-resolution scan. I think this is going to be more interesting with a dish on it, so I'm going to pop off the arrow antenna and put the Discovery dish back on. I've been kind of going back and forth here. I I need to 3D print like a quick-connect interface so I can swap antennas more easily, and that's it's on the to-do list, but there's a lot of stuff on the to-do list, so part of my problem is I don't remember what I wrote last time. Like I I have to go back and reread my comments. I have to reread the the readme file in GitHub because I don't I don't remember what I did. And people ask me sometimes, they'll be looking at my GitHub and say, well, how did you do this and how would you change this to fix it and how would you update this to work with the new version of NumPy or whatever whatever one of the requirements is that's changed, and I have to tell them I I have no idea cuz I don't remember what I did.

[00:06:04]Even with my own code here, I I had to downgrade NumPy, which is a Python plugin, because the new version wouldn't work at all with my own code, and I don't know why. So, I just stumble my way through it, and I Google all the errors and kind of apply what people what other people have done for other projects that are similar enough to this that eventually sometimes it works. All right, so I'm swapping over to the Discovery dish, which is also made by KrakenRF.

[00:06:30]And the Discovery Drive here is made to go with it, but again, pretty flexible, and the the dish here is pretty flexible, too. I've got a 1680 MHz feed on it, so I may or may not pull out some other feeds, but I'm I'm using an RTL-SDR uh software-defined radio for this at the moment, and that one is uh it is kind of limited. It goes up to about 1.7 GHz, so uh or thereabouts, so I won't be able to go into S band with that radio.

[00:06:58]Uh and if we use something like the HackRF One software-defined radio, which I also have, I'm going to have to rewrite my Python code to interface with that instead of with the RTL-SDR. All right, we're going to try another scan here with the dish, and we are going to try to look at both of the GOES satellites, so GOES East and GOES West.

[00:07:20]And if this works, then we should end up getting an image that looks like kind of a long rectangle with a bright spot on the left and a bright spot on the right, and each of those bright spots will be the satellites. I'm going to speed up this video so we don't just look at this thing forever. Going back to look at the sped-up video might also help me identify any little wobbles. Like it seems like the dish is occasionally overcorrecting, like it's maybe going up by 2 degrees and then back down by 1 degree. It's not super easy to see that at its default speed, but if I speed this up, it maybe it'll be more visible in the video. So, there we go. We have a long rectangular image with two bright blobs. The one on the left is GOES East, the one on the right is GOES West. And we can see we have a major indexing issue because we have alternating lines of bright and dark. So, the uh left direction scans are not syncing up with the right direction scans, and uh that's kind of what I suspected from the way the dish was moving. It means I have some more tweaking to do. I need to throw a delay in somewhere so that the motor catches up with where the computer is commanding it to go. All right, I've been tweaking some things with the code, and this is a little bit of a cleaner image, although um we had some high winds there on the left. So, I've been running into an issue in my scan script where the left scans and the right scans don't match up. There's an offset, and this has plagued me before when I've worked with other dishes. With the Tailgater, that was due to gear meshing, where the motor would start spinning, but the gear teeth wouldn't quite engage for about 3 degrees, so I'd be off by 3 degrees in each direction. On this one, um I've opened up the Discovery Drive to see if there's any gear meshing. There's not supposed to be with these drives, and um it doesn't seem like there is. When I tell it to go just a couple degrees one way and then a couple degrees back, there's essentially no delay between the motor running and the thing moving, so I don't think that's the issue here, but I'm not quite sure what it is. Writing code to interface with real-world physical hardware like this is one reason why I am not good at uh getting suggestions from people on the internet or pull requests on GitHub because a lot of people making the suggestions don't have the hardware, and a lot of my coding relies on trial and error. Try something, see if it works in real life, fix it, change it again. If somebody just writes a bunch of random code for me, and they don't have something to test it on, it's not going to work, and I won't know why. And that's kind of the same reason I don't use AI because I can't explain to AI how to interface with this physical device. There's not really enough documentation out there for the thing, so a lot of this is I think I'm the first one to write this program. I won't be the best. There will be other people to write this program that will interface with the Discovery dish better, smoother, cleaner code. Um but I have one of the prototype models, so I might be the first one trying to do this. This is especially true when I'm using like totally hacked-together hardware like the um traveler dishes here or the Tailgaters or the Carryout dishes. Nobody else does that. So, you can't explain that to an AI of what you're trying to do and what the feedback is or at least I don't know how to explain that to an AI. And I also like to learn the code for myself. I don't necessarily just want a bot to do it for me. And I know anytime I mention code, I will get a ton of comments down below that will say something like "Hello, I am not a spam bot, but you should definitely check out Wizbang code version 4.3 AI available at this link."

[00:10:42]Yeah, great. I look, we know the tech bros are desperate for people to actually use AI because nobody's found a a money-making use for it yet. In like maybe another decade or two, it'll be useful and it'll make money, but it's kind of a scam so far. So, I won't show every error along the way of this coding process because there are a lot of errors, but I did manage to find an amusing one. I'm trying to live update a preview image of what the uh dish or antenna is seeing as it scans just so I can kind of see how things are going.

[00:11:12]And I seem to have managed to make the Python code equivalent to pointing your camera at your screen.

[00:11:18]Yeah, um I have no idea what I did there, but uh we have an infinite uh Matplotlib graph, so I guess it's back to the programming drawing board. All right, so we have live preview working. So, um this is definitely very hacky code, and I will definitely be yelled at in the comments by people who are better at Python, and I will also definitely have 500 comments telling me to use some gimmicky AI bull.

[00:11:43]But I'm pretty happy with this so far.

[00:11:45]It's doing just about everything I want.

[00:11:47]So, my scanning program seems to be working pretty well. I've left this running and done some scans on different frequencies. So, let's see what various satellites look like. First off, we have the GOES series geostationary operating environment satellites. So, on the left, we can see GOES East or GOES 19. And on the right, we can see GOES West or GOES 18. And these are uh pretty standard uh weather satellites that I look at a lot, and you can really see in the image um the peak of the signal right in the center of those bright spots. And as you get farther out from the center, the signal starts to drop off. And this is really helpful for aiming a dish. Once you start aiming in the right area, you will start getting a signal. Kind of the um the darker reds and whatnot. And then as you move towards the center, as you move towards the precise satellite location, the signal gets stronger and stronger until you are aimed correctly.

[00:12:43]And you can see that GOES East is much stronger for me. It has a brighter uh signal in the center than GOES West.

[00:12:49]That's because the eastern satellite is a little bit closer to me. It's a little bit higher in the sky for me. So, it is just a better signal in general.

[00:12:56]So, if we look at another frequency for Inmarsat, this is a commercial communication satellite, and there's one of these over kind of the middle of North America. So, you can easily see this one. There's some choppy kind of noise in this scan. I think the signal from Inmarsat kind of varies depending on what kind of traffic is going through that on the L band. So, uh there might be moments when it is stronger or weaker, and that's why we get kind of some some sort of static or inconsistent signal strengths around that one. Next up, I wanted to look at some medium Earth orbit satellites like GPS, GLONASS, or BeiDou. Uh these are all navigation constellations, and they're in between low Earth orbit and geostationary orbit. So, they do move relative to us on the ground, but they move more slowly than a low Earth orbit satellite. So, I have a chance to catch them with this relatively slow-moving antenna. I do see some motion blur essentially. So, as the antenna is panning back and forth across the sky, these navigation satellites are also moving, and so they kind of come out as an elongated blob instead of a a circle.

[00:14:00]If we repeat the scans at different times on the same frequencies, we can see these satellites, and all three of the navigation constellations that I looked at do this. One thing I was not expecting was to see a signal, a GPS signal in geostationary orbit when I did multiple GPS frequency scans for the L1 frequency. I kept seeing this blob in the same spot that looks like a geostationary satellite, and I thought, "What what what is that?" I did this scan in 2023 and could detect some of the navigation satellites, but I didn't detect that weird geostationary one.

[00:14:34]I did a little bit of research. It looks like this is Galaxy 30, a commercial satellite with a transponder for something called WAAS or Wide Area Augmentation Service. This kind of improves GPS accuracy by adding another system in geostationary orbit that works alongside of the medium Earth orbit satellites. It basically just means your GPS devices have better accuracy. I don't know why I didn't see this in 2023 because it looks like this started in 2022 from this satellite. Uh but it is interesting to be able to spot an anomalous signal and then do the research to identify what satellite is that and why is it doing that. That was just something that I found interesting.

[00:15:14]If we look at a website like Stuff in Space, we can get a visualization of what some of these different orbits look like. We can see geostationary orbit as the ring of stuff around the Earth in near-perfect circle. Although, if we look in more detail, we can see a lot of these geostationary or geosynchronous satellites are not truly in a perfect circle. Some of them are in inclined orbits. Some of them are in graveyard orbits where they've been abandoned.

[00:15:39]And some of them have failed like um this one did not get into the proper orbit. But we can also look at those navigation satellite constellations like GPS. We can see this interesting shell around the Earth. And if we look at um my location here on the ground, this yeah, these satellites would look like they're going across at about 45° angle, which is what we see in real life with the scanner. And the other navigation constellations are very similar, although some of them have fewer satellites or they have satellites um sharing similar orbits. Like the Russian one, a lot of the satellites kind of come over in big clumps. So, sometimes you will see almost none of them directly in a specific view, and other times you'll see a bunch of them in one view. So, and then again, that's that's what I'm seeing with my little scanner.

[00:16:26]Sometimes I see only one or almost no GLONASS satellites, and then other times I see multiple GLONASS satellites as they all come over in a clump.

[00:16:36]We can look at some other ones like that Inmarsat bird we were finding earlier.

[00:16:40]And if we uh zoom in here, we can see that is the specific Inmarsat satellite that I'm looking at from the middle of North America. Yeah, it's a really cool website. It is really handy for visualizing satellite orbits, for trying to identify what are you seeing, what type of orbits are where. Yeah, I like this site a lot, and I will put a link down in the description if you want to check it out for yourself. This smeared-looking image is actually really interesting because this is the BeiDou Chinese navigation satellite system. And these satellites operate at various orbits. So, the one on the left that is just a single blob with a little bit of motion blur is in a higher orbit. And the one on the right that is a big streak is in a lower orbit. Not truly a low Earth orbit, but a lower medium Earth orbit. So, the speed of the satellite kind of matched up with the speed of my dish. So, as my dish incremented through the elevation range, it just kept catching this same satellite over and over again. It's kind of like a time lapse of a moving vehicle where it's just a streak or a time lapse of a meteor or a satellite in the sky where it's a streak of light. We're seeing the exact same thing but with a radio signal. I just thought that was really cool, and it really illustrates the difference between these two orbits of frequency. Actually three satellites because there's one in the middle that is a fainter signal, but also kind of a smeared elongated streak. All right, next up we're going to do some actual radio astronomy. And I'm sitting here in the garage on the laptop so that I can leave this setup running overnight because this is supposed to be a much longer scan. So, I'm attempting to increase something called the integration time, which is basically how long the dish stays pointed at one particular place and records data from that orientation. So, right now, it's just recording. It's going relatively fast. Even though it looks slow and it still takes over an hour to do each of the scans I'm doing, it's recording less than 1 second of data from each location. I would like to increase that up to several minutes. However, I'm running into some issues where the laptop runs out of memory trying to record for that long. So, I probably am doing it wrong. I need to do some other method of uh doing the integration, but I have a makeshift way of doing it now. Yeah, this is all very experimental. I might get nothing at all. I might not be integrating long enough to get anything. I tried to scan earlier today for about 4 hours, and I was able to see the sun in the sky, but that's not really that special. You can see the sun on any frequency. I happen to be using the uh neutral hydrogen line uh feed right now with the LNA for uh the the H1 feed essentially for 1420 MHz. There aren't really a lot of other signals to look at on 1420, so I can't really test this out and look at other things. It's basically just uh radio astronomy with this setup. Anyway, I'm running this at night to reduce interference from the sun because I would like to be able to see background signals from uh the Milky Way, from the galaxy. And the idea here is to get signals in that neutral hydrogen frequency range that are coming from interstellar gas clouds. Um yeah, there's a lot of interesting stuff you can do with this. I'm hoping to make a picture of some of the interstellar hydrogen sources in the sky, which would be really cool. But again, I've never successfully done this before, so I don't know if it's going to work this way. What a lot of professional scientists will do is a drift scan where you basically just aim the dish at one elevation, you let the Earth's rotation carry you past uh the night sky, and you record that all night. Then you move it up a degree, you do it again, and so on and so forth. And if you want a 30° uh elevation range in your image, you need to do it all month. So, I'm a little impatient. I don't want to wait that long if I can possibly do it another way or take a shortcut. We're going to try the shortcut, and it may or may not work. And this is the frustrating and/or tedious part of doing radio astronomy stuff, especially when I'm developing my own code. If I have an error in the code, if something goes wrong, I won't know until tomorrow, and then I'll have to try to fix it, and then run it again, and it will take possibly 24 hours to really iterate uh changes to the code or bug fixes, and my attention span doesn't last that long. So, we may um we may or may not get some interesting data. If we don't, we'll have to come back to this in a future video because this one has already been running a little bit long, and I'm getting a little antsy to do other projects. So, let's just see what happens.

[00:21:09]All right, it is morning, and last night I thought of about uh four things that I need to change on this code. So, two major errors, um one kind of oversight that I forgot, and then one kind of improvement that makes things better. So, we're going to edit these.

[00:21:26]Um I did get a scan last night. However, it doesn't really look like anything. We can tell there's some signal noise coming from the ground. There is kind of radio emissions either from the ground or reflections, uh stuff bouncing off of trees. I think I'm going to have to run this again, and have the dish start at a higher elevation to avoid some of that low elevation noise.

[00:21:51]And I'm still not convinced that my integration time is long enough. So, uh we might have to tweak that some more.

[00:21:57]Some other astronomy-related complications, um since I am in the northern hemisphere, if I look up in the sky, I'm looking up at 45° angle or thereabouts, and everything in the sky to me seems to go in an arc because I'm kind of looking uh down at things like the sun. You know, the sun rises, it goes in a curve, it comes down. Let's see if I can do a scan that will illustrate that. If I scan the sun using my astronomy code that compensates for Earth's rotation, then the sun in the scan should remain in the same place horizontally, but it should be a little bit of an elongated blob vertically because the sun through my perspective is not only going east to west, it is also rising in the sky, and my code does not account for that uh angular offset. It does not account for elevation changes relative to me based on the Earth's rotation. So, here's our scan of the sun, and yes, it looks pretty much like I expected. It is elongated in the vertical direction because I'm not compensating for the sun changing elevation, but it's pretty much the right size in the azimuth range because I am tracking along as the Earth rotates. It still looks a little bit funny. I I could maybe clean up some of the indexing a little more, but um yeah, that's basically doing what I want. If I look too far down uh towards the horizon, I get all that ground noise.

[00:23:19]If I look too far up, since the dish is using kind of circular coordinates, um basically if I aim the dish straight up and tell it to rotate, it's just going to spin, and it's always going to look at a position straight up, uh which is why people do things like drift scans because you can aim your dish straight up, let the motion of the Earth move you. Um but for my purposes, basically the more I go up towards the top, the more I'm just kind of looking in the same circle, and I have basically less spatial resolution at higher elevations than I do at lower elevations. The astronomy stuff is pretty hard. Just imaging satellites, I kind of understand that.

[00:23:55]I've done that before. I can build on my past knowledge, but I'm still learning how to do all of the bits and pieces that go into radio astronomy. So, I think we might have to come back to that in a separate video because this one is already going kind of long, but I do have a couple other satellites that I want to try looking at while we have this set up. So, I have something pretty cool that I bought from a viewer. Um this is a military satcom antenna, and if we can get it uh aimed and tracked, we could maybe make a sky map of uh fleet satcom birds, which would be pretty interesting. I've talked about this system before. It's a US Navy and Air Force communication satellite constellation that was originally launched in the '70s, and they didn't have any access control. So, anybody with the right radio can use these as a um as a repeater system. It's not legal to do, but people still do it, especially in South American countries and in Russia and other countries that don't really care about US law. It's a very popular to use these as kind of a space-based CB radio system. All right, I think that's how this all goes together. So, normally it's got this little tripod mount. You uh set everything up, you aim it at your satellite or generally south if you're in the northern hemisphere, and uh then your military unit is now communicating with headquarters. Now, I would like to use this on the Discovery Drive. I think it's light enough. It doesn't actually weigh very much. I just have to find a way to adapt this tripod mount to the plate on the Discovery Drive. So, I think we're going to have to do some more 3D printing for that. So, the first time I tried the UHF satcom frequencies with the Trivec antenna, I got absolutely nothing, and I was a little confused at first until I looked at my settings, and I accidentally had the bias T turned on. Don't do that. Don't Don't use the bias T with an unpowered antenna with no LNA. You're just feeding voltage into the antenna, which is not good for anything. Um I'm lucky I didn't burn something out or reflect voltage back to the SDR. So, big mistake on my part. Um we tried again without the bias T, and I still got kind of conflicting results here.

[00:25:58]There's definitely some signals, but it's hard to really pinpoint directionality on these. Um this antenna is I think more directional for transmitting than it is for receiving.

[00:26:09]Um so, maybe it doesn't do a great job of narrowing down a focus on a specific satellite. So, it just kind of got these blobs across the entire sky. There's supposed to be one major orbital slot uh for these over the continental US. So, if I'm only seeing one satellite, I should see it kind of in the middle.

[00:26:26]There's another one uh way off to the west that I maybe saw on a different frequency. I could see a strong signal way way off to the west right at the horizon essentially.

[00:26:37]But this satellite I think is technically below the horizon for me, so unless I'm getting some atmospheric uh scattering, unless I'm getting some reflections, I don't know if I'm actually seeing it. Round numbers, especially with an SDR, round number frequencies are very often some kind of interference. So, this could just be a random 250 MHz um noise pattern. So, right now, I'm actually scanning to the north because Russia operates some military uh communication satellites on similar frequencies in that UHF band uh below 300 MHz, but they have them in really weird orbits. Um it was really difficult for Russia to get anything into geostationary orbit in the old days, so they would put things in what's called a Molniya orbit or a Tundra orbit where it would basically go kind of weird big oval shape, and they had a number of satellites in these orbits.

[00:27:27]And this would not only be cheaper and easier to launch into than a uh geostationary orbit, it would also serve higher latitudes like Siberia, so they could get television this way. Although, they would often have to have a a tracking dish of some sort because these satellites would be coming in north and south relative to observers on the ground.

[00:27:47]Anyway, they also have some other transponders on there like uh some communication stuff around uh 279 MHz, and that's what I'm looking at now. You might notice my bracket changed there.

[00:27:59]I'm using an orange one now. I I reprinted that interface bracket in uh PC blend polycarbonate. That's supposed to be a little bit stronger, so I feel better leaving that out here long term. I'll probably throw that on uh Printables or Thingiverse or something if people are interested in checking that out. So, I scouted this a little bit beforehand with SDR++ and I did see what looked like a signal on 279.45 MHz in that uh northern direction in that Molniya orbit. Um it's an inconsistent signal, so it looks like we are getting a little blip from it here and there. You can see that kind of in the lower half of the uh the preview image there, but it's unfortunately not a steady signal, so we're not going to get a nice image of the satellite. We're just going to see brighter spots when it happens to be transmitting something more powerful. There's another system on GPS called SARSAT or search and rescue satellite. This is actually on uh many different satellites, but it is a uh transponder that picks up signals on 406 MHz, which is kind of an international distress frequency for emergency beacons, and you can see the um transponders active on the GPS satellites without any data. If you look at this image, there's kind of a lighter blob. That is a GPS satellite with its SARSAT transponder running, but not receiving anything to be retransmitted.

[00:29:20]And then down at the bottom, you can see that there's one that picked up a signal and retransmitted it um as my antenna was passing over that GPS satellite. I just thought it was really cool that you can visualize how some of these satellite systems work by doing a microwave scan like this.

[00:29:37]All right, we are out here at the Sandland Radio Observatory, the 18-ft geodesic radar dome, and we're going to try the same scanning code here on the big dish that lives inside the dome.

[00:29:52]As usual, there are a lot of weird echoes in here because it is a big a big sphere, so we're inside of that.

[00:30:01]All right, my code is slightly different for this dish, so it is not actually been tested yet, but if everything works, the dish should swing down and start scanning the southern sky. The potentiometers in there are not as accurate as the encoders in the discovery drive. So, the dish is hunting. It's I am telling it to go like 1° at a time, and sometimes it's going like 3° at a time, it's going back. So, the scan is going to be very inaccurate. It's going to be Yeah, just more and more issues here.

[00:30:30]All right, the scan has finished, so here is what the GOES satellites look like on the big dish, and this is both better and worse than what I was getting from the discovery dish. It's worse because the signal is not as good. They are fainter signals, but it's better because they are smaller.

[00:30:51]So, the beam width of this dish is tighter. The focus is tighter. With a bigger dish, the bigger the reflector, the tighter your focus is. So, with the discovery dish with the tiny little reflector, we got just a big smear of GOES signal all across the approximate elevation and azimuth, but with the big dish, it does focus in much closer. So, the blobs are smaller. That really illustrates the effect of beam width, of dish size. Now, they are fainter because I was using the wrong feed. This is a 2.3 GHz feed instead of a 1.7 GHz feed.

[00:31:27]It's also a it's a wideband LNA instead of a Sawbird GOES. So, I'm getting less signal overall. I ran that scan again with a higher gain setting, and we got sharper images from both of the GOES satellites, but we also got more ground noise. So, I think a Sawbird GOES LNA would be better than the wideband LNA.

[00:31:46]We'll have to try this again with a better feed and a better LNA in the future. And I would also like to do some more adjustments to the code on the big dish because it still has some issues, but overall, I think this was a good first try. I also looked at the Inmarsat band again, and we can see that same satellite that we could see from home.

[00:32:03]With the discovery dish, the Inmarsat signal was a bigger blob because again, that dish has a wider beam width. And here at Sand Land, it's a smaller blob, and the Inmarsat signal is still a little bit inconsistent. So, in both scans, we get those little blips of stronger data along with the baseline sort of background data from Inmarsat.

[00:32:23]So, I think we're going to wrap this video up. It's a decent starting point for some of my future radio astronomy experiments, and I know I've been saying that in several videos, but I'm sort of building my way up to learning enough about radio astronomy, about coding, about the behavior of some of these antennas to be able to do something a little more interesting with it, and hopefully it is interesting. I definitely found the satellite stuff interesting, and I learned new things while I was doing this video, as I often do when I'm doing these projects. I learned about some satellite signals that I was not aware of. I learned about what some of these satellite signals look like, how they appear over a long-term scan, what they look like basically to a human eye versus a radio, which I find really interesting. I feel like this is a really cool way to visualize things like satellite orbits, like radio signals, in a way that is much more intuitive, at least to me, than just looking at an SDR waterfall display, or looking at a bunch of math on a page. That often means little to nothing to me, but being able to see a picture of these signals from different satellites really makes sense to me. It really helps me understand a lot of this stuff.

[00:33:32]So, I think that's cool. Hopefully, it's helpful to some other folks out there.

[00:33:36]If you want to try this for yourself, if you have a discovery drive, or really any rotor system that can use the Hamlib or rotor control library, my code should be somewhat flexible, although it does have a lot of issues, and it does have a lot of room for improvement. So, I will put links to GitHub where you can find my code, and you are certainly welcome to fix it, improve it, make it better for your specific application, your specific drive.

[00:34:02]I'm just going to make it all open source. If you found this video interesting, and you'd like to support videos like this, then Patreon is a great way to do that. YouTube income is very inconsistent, and especially has gone kind of downhill lately. So, Patreon is really helpful to keep me doing videos along these lines. And of course, it always helps the channel if you click the like and subscribe button, and that's uh helps you keep on top of future videos that come out when I do follow-ups to things like this. As I said, we will be trying to do some more radio astronomy in the future, but I have a few more things to figure out before we get to that point. Until then, thank you to everyone for watching, and we'll see you next time.