How to receive images directly off of Satellites

General Understanding Most weather satellites like NOAA or Meteor M2 transmit images back down to earth over VHF or UHF radio bands. These are all free to receive without a license, just don’t transmit on frequencies you don’t know unless you know exactly what you are doing. They send down images of the earth on different light spectrums and with different data like rain and thermal data overlayed, these can be used for Meteorology or just as a thing you can brag to your friends about. There are several methods to receive these radio transmissions, from the easy way with an SDR(Software Defined Radio) and a Laptop to the hard ways with just a HAM Radio and a phone. All you need is a device capable of receiving these frequencies and a device capable of decoding the received transmissions. In this guide we will go into how to receive analog NOAA APT images, meaning we will just need some simple equipment you might just have laying around at home. What is NOAA APT? NOAA Weather Satellites are a series of satellites sent up by the National Oceanic and Atmospheric Administration for the purpose of further studying our earth and for Meteorology Purposes. They send down images using APT, (Automatic Picture Transmission) thissystem is an analog image transmission system developed for use on weather satellites. They also send down images using other types of Transmission but we won’t go into that since this is a beginners guide. Receiving NOAA APT using an SDR, a Laptop and a V-Diapole Antenna (Easy Method, $30 - $90) This is the easy method, it costs anywhere between $30 and $90 depending on if you want the good equipment and if you want to DIY some stuff. Let’s first talk about what a Software Defined Radio(SDR) is, an SDR is a device that digitally receives radio signals, the one I’m going to be referencing in this guide is the RTL-SDR V4, a USB dongle type SDR, which you simply plug into your Computer, get some software like SDR++ or SDR# running (Personally I recommend SDR++) and you’re ready to go besides for some simple driver installations. Another thing you will need with an SDR is an antenna with the correct connector. In this case we will be using a V-Diapole Antenna (also commonly refferred to as a “Rabbit Ears Antenna”) since it is the cheapest and easiest to use in this scenario. You can either build this kind of Antenna yourself (there are lots of guides for that on the internet) or buy one like the RTL-SDR Blog Multipurpose Dipole Antenna Kit Now let’s talk about how to set up the software. In this case, we will be using SDR++. To set up your RTL-SDR BLOG V4, please use this guide but do not complete Step 13 and further since we will be using SDR++. Now download SDR++ Nightly from this page, extract the downloaded file and open it, it should look something like this: Go ahead and open sdr++.exe This is what you should be greeted with: Firstly, select RTL-SDR as a Source Now, select your SDR and change the sample rate to the highest possible (for example 2.4 MhZ or 3.2 MhZ), this will ensure you have the highest possible quality. Also slide the “Gain” slides to the maximum. Now that we have our software set up, we simply need to choose which Satellite to receive and learn how to track it. At the time of writing this there are 3 functional NOAA Satellites you can receive from. NOAA 15, 18 and 19. In this case I will be using NOAA 19, but you should just use whichever Satellite passes over you at the most convinient time. To see the frequencies of these Satellites and where they are/when they will pass over your location, you should use N2YO. After searching for whichever Satellite you want to receive, you should land on a page similar to this: The most important information we need to extract is the time of the pass, the Maximum Elevation and the frequency. 1: Start time, this is the time the Satellite will start to be visible/able to be received 2: Max elevation, this is the Maximum elevation in degrees the Satellite will go over the horizon, 1° meaning just barely and 90° meaning directly overhead, I would not recommend trying passes with a Max. Elevation of under 25° 3: Frequency, the first frequency (in this case 137.100MhZ) is the APT Frequency for this particular Satellite. Now, to actually receive the Satellite you will most likely need to go outside. So bring a laptop, your radio equipment and your phone with you and set it up in an area with a mostly clear horizon. Now get an app like Look4Sat on your phone, this will help you correctly track the Satellite with your Antenna to get the best frequency possible. Set your Radio setting to WFM on SDR++, then adjust your recording settings to either Audio or Baseband, Audio will have the smallest filesize but a tiny bit of quality loss and Baseband will have a big filesize but you will be able to do the most with it. Once the satellite starts being visible according to Look4Sat, go ahead and press on Record on SDR++ and start tracking the Satellite with your antenna like this: Each V-Diapole antenna side should be around 53cm long and there should be an angle of about 120° between them. Now you should get a signal that looks like this on SDR++: If you are using the Audio recording setting you should adjust your Bandwidth tightly around the signal, the bandwidth is the little white selection field around your cursor. This will make the signal get a little better. After the pass, stop the recording and download SatDump, we will use this to decode the Signal we just got into an image. Extract the downloaded file and open satdump-ui.exe This is what you should be greeted with: Firstly, search for “NOAA APT” in the search bar: Now select your recording, where you want the images to be stored and if you recorded in baseband or audio. Also select which NOAA Satellite you recorded and turn off “SDR++ Noise Reduction”, Samplerate should be set automatically. Then press Start to start decoding. You should first see something like this: Then it should turn into something like this: And after a tiny bit it should send you back to the start screen, this means your decoded images are in the folder you set as output. This is what you should expect as an output in the folder: Here you see your decoded image in lots of different channels like Thermal, with rain overlay, with a map overlayed, etc. Congrats, you have done it! You have received images from a Weather Satellite! Example Images NOAA METEOR This has been an MIS Blog Post.

Space · 2024-11-23

Chinese Engine Test Accidentally launches and explodes.

A rocket stage test firing by Chinese commercial company Space Pioneer ended in catastrophic failure and a dramatic explosion Sunday. Space Pioneer conducted a first stage engine test of the rocket Tianlong-3 Amateur Footage captured by Gongyi citizens and posted on Chinese social media shows the nine-engine test stage igntiting and then, exceptionally, taking off. Hold-down clamps and other structures are typically used to securely keep stages in place. Thankfully, no one got hurt during this shocking accident. Space Pioneer issued its own statement later, stating there was a structural failure at the connection between the rocket body and the test bench. The rocket’s onboard computer automatically shut down the engines and the rocket fell 1.5 kilometers southwest. This launch site was the same site that had a big catasthrophe on the 22nd of June (2024) where debris of a Chinese Satellite Mission fell over a populated area. This has been an MIS Blog Post.

Space · 2024-07-01

NOAA's newest Satellite Launch

Introduction The National Oceanic and Atmospheric Administration (NOAA) has recently launched a new Geostationary Operational Environmental Satellite (GOES) on SpaceX’s ‘Falcon Heavy’ Rocket. It was launched at 5:26 PM EDT frm Kennedy Space Center, Florida, United States. The newest Satellite called GOES U/19 is the fourth and final satellite in the GOES-R Series. Where GOES-19 will work in tandem with GOES-18, which serves as “GOES West.” Together, these satellites will watch over more than half the globe – from New Zealand to the west coast of Africa and from near the Arctic Circle to the Antarctic Circle. The current GOES East (GOES-16) will become an on-orbit backup. Details Liftoff happened at 5:26 PM EDT without problems. Both of the side boosters were decoupled at about T+00:02:30, Booster 1 and 2 Landed at about T+00:08:09 and T+00:08:14 respectively. The Satellite was successfully dropped off in Geostationary Orbit at T+04:30:11, it has a planned lifespan of about 15 years. This has been an MIS Blog Post.

Space · 2024-06-27

What are Black Holes?

The Basics A Black Hole is a Celestial Object that has a very strong gravitational pull that not even light can escape. This happens because Black Holes have an astronimically large mass. The lowest-mass known black hole belongs to a binary system named XTE J1650-500. The black hole has about 3.8 times the mass of our sun. How do they form? Black holes are formed when a massive star reaches the end of its life and implodes, collapsing in on itself. Now you might be thinking our sun could become a black hole, but that is wrong. It’s way to small for that, The sun would have to be about 20 times as massive to become a black hole at the end of it’s life. Different Parts of a Black Hole This illustration of a black holes show us all the different parts. The Singularity is the core of a black hole, this is where all the matter has collapsed into, making a tiny, infinitely dense point. The Event Horizon is the part of the black hole that is actually black, if anything is at this point it will not be able to escape. Relativistic jets are the jets of particles and radiation being produced when a black hole feeds on stars, gas or dust, this results in the jets of particles and radiation blasting out from the black holes poles at near light speed. They can extend for thousands of light-years into space. The Accretion disc is a disc of superheated gas and dust which whirls around a black hole at very fast speeds, producing electromagnetic radiation that reveal the black holes location. The Innermost stable orbit is the inner edge of an accretion disc, it is the last point where an object can orbit safely without falling past the point of no return This has been an MIS Blog Post.

Space · 2024-06-21

How to destroy Black Holes

There is currently no known physical process on how to destroy a Black Hole, but there is the theory that hawking radiation could destroy a black hole after a long period of time. This theory was proposed by physicist Stephen Hawking, the theory suggests that black holes emit radiation due to quantum effects near the event horizon. After an incredibly long time this radiation could cause the Black Hole to lose mass and eventually “dissapear” completely. This process would take ages (far longer than the universe’s current age). This has been an MIS Blog Post.

Space · 2024-06-21

What is Delta-V (Δv)?

What is it? Delta-V (Δv) represents the maximum change in velocity a rocket can achieve. It is a measure of the rocket’s capability to perform maneuvers such as launching, orbiting, or landing. Importance Delta-V (Δv) is crutial for any mission, since you need a certain amount of it to perform the mission, therefor it is calculated beforehand How to Calculate Delta-V (Δv) The equation used to calcute Delta-V is: Δv = vₑ * ln (m₀/mₜ) in which vₑ is the exhaust Velocity, m₀ is the initial mass (e.g a fully fuled rocket) and mₜ being the final mass (e.g a half empty rocket) This has been an MIS Blog Post.

Space · 2024-06-19

What is Thrust to Weight Ratio (TWR) in Rockets?

Thrust to Weight Ratio (TWR) is a dimensionless ratio of thrust to weight of a rocket, jet engine, propeller engine, or a vehicle propelled by such an engine that is an indicator of the performance of the engine or vehicle. In rockets, it indicates how fast you can go with the weight and thrust of your rocket. A higher TWR means that you can go faster, while a lower TWR means you go slower. On Earth During liftoff you need a TWR of atleast 1.00 to overcome the atmosphere and gravitational forces. In Space While in space, TWR doesn’t really matter due to there not being an atmosphere and gravitational forces being much lower or in some cases even nonexistant. A low TWR in space just means that you will go slow, which in many use cases does not matter at all. Even if you cannot execute a burn due to your vessel being way to slow, you can still, in most cases like changing apoapsis or periapsis, break up the burn into many different burns. How to Calculate TWR Thrust to Weight Ratio TWR is calculated by dividing the Thrust by the Weight (TWR=T/W) Weight Weight is calcuated by multiplying Mass and Acceleration due to Gravity (W=m⋅g) For Earth, The Acceleration due to Gravity would be 9.81 m/s² Thrust Thrust is usually indicated by the Rocket Engines Manufacturer, it is usually measured in Newtons (N) It can be calculated, but calculating it requires some more advanced math that I’m not gonna go into detail with. Here is an article from NASA on how to calculate thrust. Example Here is a generic example of a TWR calculation: TWR= 735,750N/800,000N ≈ 1.09 (Note: To have a TWR > 1.00, thrust must be greater than the weight, so double-check the numbers to ensure accuracy) This has been an MIS Blog Post.

Space · 2024-06-18

How do Geostationary Orbits work?

What is an orbit? An orbit is a regular, repeating path that one object in space takes around another one. It is achieved by going (In earths case) over the atmosphere and achieving a speed that “outruns” the gravitational pull, making you do circles around the earth. Sometimes orbits are completely circular, othertimes they’re elliptical. What is a Geostationary Orbit? A Geostationary orbit is when the object that is orbiting the planet always stays at the same spot from the planets perspective. How is a Geostationary Orbit Achieved? A Geostationary Orbit is Achieved by being exactly 35,786 km over the equator. At this altitude, a satellite’s orbital period matches Earth’s rotation period of approximately 23 hours and 56 minutes. Usecases The most common usecase of a Geostationary Orbit is either a Meteorological satellite or a communications satellite. Even amateurs can receive signals from Meteorological Satellites in geostationary orbit, like for example the GOES series of satellites. This has been an MIS Blog Post.

Space · 2024-06-18

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