We are excited to announce that we are celebrating yet another significant milestone for the SatNOGS project as the SatNOGS DB stored its 200 millionth data frame!!!
The milestone data frame
The 200 millionth frame was received on the 31st of October. It was a frame of satellite 47438 – UVSQ-SAT that was received by ground station 2760 – M0GKK-BB. And it was observation #8429588 for the SatNOGS Network.
We can only be thrilled with the enormity of this massive number, and we are also very grateful for these contributions. Congratulations to all for reaching such a fantastic milestone!
The SatNOGS DB
The SatNOGS DB is a component of the SatNOGS project, and it is a collaborative effort to create a holistic, unified, global database for all the artificial objects in space. A point of reference for all the satellites and spacecraft. Data frames are sent to the SatNOGS DB from stations belonging to the SatNOGS Network, as well as independent stations and telemetry forwarders. The SatNOGS DB receives frames from more than 1500 stations around the globe. Tracking over 1650 satellites and 3040+ transmitters in 50 different modes and ten bands. All these add up to the amazing 200 Million data frames received. Thus constituting the SatNOGS DB, the biggest, open-source and crowd-sourced database for openly distributed satellite data.
The Libre Space Manifesto
Like all the Libre Space Foundation projects, the SatNOGS DB also adheres to the principles of the Libre Space Manifesto. Supporting and promoting Openness (Open development and governance, open data, open-source, and free access to Space) with dedication to enhancing knowledge and scientific research.
The SatNOGS Community
SatNOGS is brought to life and expanding because of the unceasing collaboration, devotion, and ongoing contribution of its community. The latter is comprised of a vast network of space enthusiasts, radio amateurs, university teams, satellite operators and ground station owners. All the members and the open-source supporters who make up the SatNOGS Community add to the project’s success.
To all of you, we are whole-heartedly grateful!
Do you want to join SatNOGS and be part of the next Milestone?
If the SatNOGS project has sparked your interest, and you love space and open-source technologies, then there are many ways you can contribute. You can help with the SatNOGS DB by joining the SatNOGS Network, setting up a station or forwarding the frames to the SatNOGS DB through the SiDS protocol. You can also opt to create decoders to help us decode the load of data received and visualise them on the SatNOGS Dashboard. If you are fluent in Python and/or JS, you can contribute to the satnogs-db web application.
The SatNOGS Community is a global, diverse, inclusive, collaborative, open community that welcomes people from different backgrounds. People who wish to contribute by devoting their valuable time, ideas, knowledge and expertise to the SatNOGS project. If this appeals to you, you can start by checking the SatNOGS knowledge-base wiki. You are also welcome to join our community forums and drop us a line on the chat. Get in touch with us!
We are looking forward to having you onboard the SatNOGS project and community. Join us now so that you are part of our next Milestone!
Among amateur radio operators, the Icom 7610 and Elecraft K3S radios stand out as popular choices, renowned for their superior performance and advanced features. Despite their impressive attributes, these radios can be further optimized by adjusting their SSB listening receiver...
The SatNOGS Network has achieved yet another amazing Milestone! It has reached its eight millionth observation, and we are deeply grateful to the entire Community for this achievement!
Eight million Observations
On the 11th of August 2023, observation #8000000 was uploaded on the SatNOGS Network by station 2173 – PE0SAT-21 in the Netherlands. The observation was scheduled by Jan Van Gils (PE0SAT), receiving data from satellite TigriSat. The eight millionth observation is of good quality.
It is an observation coming from an operational satellite that has been making its way through space for almost ten years.
TigriSat
TigriSat is a 3U CubeSat built by Iraqi students in collaboration with the La Sapienza University of Rome. Its mission is to detect dust storms over Iraq. For this, the CubeSat features an RGB camera. It was launched into space by the Dniepr launch vehicle from Orenburg, Russia, on June 19, 2014. TigriSat is considered to be Iraq’s first satellite.
SatNOGS achieved another milestone!
We are thrilled that SatNOGS has achieved another astonishing Milestone. Everything accomplished is thanks to the active and vibrant community. As is the case, every SatNOGS achievement results from the collaborative work and the continuous efforts made by hundreds of ground station owners around the globe. They are the ones who have made this milestone (and everything) possible by scheduling observations, tracking satellites and, in general, dedicating time and effort to the success of the SatNOGS project.
SatNOGS in Numbers
The SatNOGS network counts over 240+ fully operational ground stations and 150+ in testing mode. The observations come from 1545+ satellites and 2890+ transmitters delivering over 192M data frames. As the numbers show, SatNOGS has significantly expanded and has become the biggest, global, open-source network of satellite ground stations.
Outer Space Open For All (The Libre Space Manifesto)
All Libre Space Foundation’s projects are built to enhance scientific research and knowledge about Space and to enable everyone interested in exploring Space for peaceful purposes. These values are also at the core of the Libre Space Manifesto.
Outer Space Open For All (the SatNOGS way)
Abiding by the Libre Space Manifesto values, SatNOGS is a project that not only is built and developed in a modular, open-source way but also the data collected is distributed openly. The SatNOGS community offers support and guidance in onboarding new members and even helps satellite teams with their missions. Throughout its years of operation, SatNOGS has helped hundreds of Satellite Teams from all over the world to successfully identify and track their satellite. The community and its members assist missions from all corners of the world to run their experiments and tests and successfully complete their missions. Not only can the community help you communicate with your satellite as it schedules around 10,000 observations per day, but it can also guide you throughout the onboarding process. Guide you through the actions you need to take and help you with creating and populating the dashboard of your mission with the data received. All you need to do is contact the SatNOGS team early on and provide the necessary details and information about your mission.
Want to join the SatNOGS community and be part of the next Milestone?
The SatNOGS community is open and inclusive, welcoming everyone who wishes to contribute their time, knowledge and expertise to the project. If SatNOGS has sparked your interest and you want to learn more, check out the SatNOGS wiki knowledge base. You can drop us a line on the community forums and the dedicated SatNOGS chat. We would love to hear from you and have you join the SatNOGS network and community and be part of the next million observations.
Join SatNOGS now and help make Outer Space Open for All!
We are excited to share with you the news of SatNOGS achieving yet another milestone, as it has reached 7 million observations.
On the 8th of January, observation #7000000 was uploaded on the SatNOGS Network by station 901 – VE2WI – UHF in Quebec, Canada. The observation was scheduled by Laurent Beaudet, the station owner, receiving data from AMSAT-OSCAR 7. Though the seven millionth observation is of a rather poor quality, it is, in fact, coming from a satellite that has been making its way through space for almost 50 years.
Satellite AMSAT-OSCAR 7 was launched on November 15, 1974, and by mid-1981, it had been rendered non-operational due to battery failure. It was almost 20 years later, in 2002, that it was brought back to life when one of the shorted batteries became an open circuit, and the satellite could operate again. This time using solar panels. What this means is that when in eclipse, the satellite cannot supply enough power to the transmitter to modulate the signal. When continuously illuminated, though, the mode will alternate between A and B every 24 hours. AMSAT-OSCAR 7 became SatNOGS‘s 7 millionth observation 20 years after its resurrection and 49 years after its deployment.
SatNOGS has achieved yet another astonishing Milestone, all thanks to its community. This is the result of the collaborative work and the continuous efforts made by hundreds of ground station owners around the globe. They are the ones who have made this milestone possible by scheduling observations, tracking satellites and, in general, dedicating time and effort to the success of the SatNOGS project.
So let us celebrate this Milestone by taking a closer look at some of the highlights of 2022 for SatNOGS and for everything the SatNOGS Community has achieved in the past year.
Making over 1.670.000 observations, an average of 4.5K observations per day.
Scheduling a sizeable number of observations per deployment ….(There was a time in 2022 that we scheduled over 1800 observations for the first 48 hours of a launch…)
On average, receiving the first signals of the satellites within the first few hours of their deployment.
Contributing to missions with more than 11K observations.. the GASPACS mission was one such mission…
Collaborating with International satellite teams from over 15 countries (Brasil, USA, Spain, Italy, France, Luxemburg, Germany, Finland, Turkey, Israel, UAE, India, Nepal, Korea, Taiwan, and Japan) and more than 20 Universities from around the world.
Celebrations and Goodbyes…
In 2022, SatNOGS and its Community celebrated anniversaries together as satellites continued their lonely yet magical journey through space.
and…
And bid goodbye to satellites that travelled in space and re-entered gloriously.
and
But we were not saddened…
As many of the satellites provided us with wonderful images before they disappeared…
RamSat, a CubeSat built by the students of the Robertsville Middle School in Oak Ridge (Oak Ridge Public Schools), Tennessee, USA, with the supervision and mentorship of the Oak Ridge National Lab, provided us with some breathtaking photos…
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and enlighted us with their insightful analyses that taught us beautiful things about space and satellites. The RamSat team was kind enough to share with the SatNOGS Community their findings during RamSat’s quest in space. The team shared some detailed analyses and helpful lessons learned. Among these analyses falls their input on the extreme temperatures RamSat experienced in space due to the intense conditions. https://community.libre.space/t/ramsat-mission-progress/8219/52.
Tracking our very own…
Among the year’s highlights was the return to space of the Libre Space Foundation. It was a moment of great excitement for the LSF team to track the QUBIK mission. To hunt the PICOBUS deployer and PocketQubes, QUBIK-3 and QUBIK-4, as they made it to orbit onboard Firefly Aerospace’s Alpha Flight 2.
Art and SatNOGS
A few months before 2022 was gone, Nye Thompson, a visual artist and a member of the SatNOGS Community, began working on an experimental art project using SatNOGS.
The project uses SSTV transmitted via a satellite as a way to generate and distribute new images. It’s also a kind of networked performance with the satellite.
You can find more details about how you can contribute to SatNOGS art in the dedicated thread on the Community Forum.
Wrapping up …
2022 was a great year for SatNOGS as the Network, and the DB continued to grow, and its Community kept expanding. SatNOGS has now proudly reached over 400 ground stations spread in 50 countries across the globe, having tracked 1177 satellites, 2180 transmitters, 165 million data frames and 7 million observations. It thus remains the world’s biggest open-source network of satellite ground stations.
Led by a Community that fosters collaboration, inclusivity and diversity, SatNOGS welcomes everyone who wishes to contribute their time, knowledge and expertise to the project. A project built and developed to enhance scientific research, knowledge about Space and to enable everyone interested, to explore Space for peaceful purposes, as the Libre Space Manifesto states explicitly.
You are welcome to join the project too, and be part of our next Milestone as we work hard to make…..
We are excited to share with you, the new milestone achieved by the SatNOGS network, as it has reached 6.000.000 observations!
On the 27th of May, observation #6000000 was uploaded on the SatNOGS network by station 1936 – VK4JBE-UHF, in Camp Hill, Queensland, Australia . The observation was scheduled by VK4JBE, the station owner, receiving data from AAUSAT-II, a Danish CubeSat of the University of Aalborg. Although the satellite is operational, it seems to be tumbling in space, resulting in generating rather poor observations.
Achieving the astonishing 6 Millionth Observation is a Milestone that SatNOGS has reached thanks to its community. This too is the result of the collaborative work and the continuous efforts made by hundreds of ground station owners around the globe. They are the ones who have made this milestone possible, by scheduling observations, tracking satellites and in general, dedicating time and effort to the success of the SatNOGS project. So let us take a closer look at some of the astonishing statistics of the project.
SatNOGS in Numbers
The SatNOGS network counts over 265+ fully operational ground stations and 145+ in testing mode. The observations come from 810+ satellites and 1500+ transmitters having delivered over 144M data frames. As the numbers show, SatNOGS has expanded greatly and has become the biggest, global, open-source network of satellite ground stations.
Outer Space Open For all
SatNOGS, much like all Libre Space Foundation’s projects, is built to enhance scientific research, and knowledge about Space, and to enable everyone interested, to explore Space for peaceful purposes. These are all, values that are at the core of the Libre Space Manifesto and guide SatNOGS too.
Thus, the project itself is not only built and developed in a modular, open-source way but the data collected is also distributed openly. The community offers support and guidance in onboarding new members and it even helps satellite teams with their missions. Not only can the community help you communicate with your satellite but they can also guide you throughout the onboarding process. All you need to do is contact the team and provide the necessary details and information about your mission.
Want to join the SatNOGS community and be part of the next million observations?
The SatNOGS community is open and inclusive, welcoming everyone who wishes to contribute their time, knowledge and expertise to the project. If SatNOGS has sparked your interest and you want to find out more, check out the SatNOGS wiki knowledge base. You are welcome to drop us a line on the community forums and the dedicated SatNOGS chat. We would love to hear from you and have you join the SatNOGS network and community.
Last year, I was "car camping" with a bunch of friends - all of which happened to be amateur radio operators. Being in the middle of nowhere where mobile phone coverage was not even available, we couldn't resist putting together a "portable" 100 watt HF station. While the usual antenna tuner+VSWR meter would work fine, I decided to build a different piece of equipment that would facilitate matching the antenna and protecting the radio - but more on this in a moment.
A bit about the Wheatstone bridge:
The Wheatsone bridge is one of the oldest-known types of electrical circuits, first having been originated around 1833 - but popularized about a decade later by Mr. Wheatstone itself. Used for detecting electrical balance between the halves of the circuit, it is useful for indirectly measuring all three components represented by Ohm's law - resistance, current and voltage.
Figure 2: Wheatstone bridge (Wikipedia)
It makes sense, then, that an adaptation of this circuit - its use popularized by Dan Tayloe (N7VE) - can be used for detecting when an antenna is matched to its load. To be fair, this circuit has been used many decades for RF measurement in instrumentation - and variations of it are represented in telephony - but some of its properties that are not directly related to its use for measurement that make it doubly useful - more on that shortly.
Figure 2 shows the classic implementation of a Wheatstone bridge. In this circuit, balance of the two legs (R1/R2 and R3/Rx) results in zero voltage across the center, represented by "Vg" which can only occur when the ratio between R1 and R2 is the same as the ratio between R3 and Rx. For operation, that actual values of these resistors is not particularly important as long as the ratios are preserved.
If you think of this is a pair of voltage dividers (R1/R2 and R3/Rx) its operation makes sense - particularly if you consider the simplest case where all four values are equal. In this case, the voltage between the negative lead (point "C") and point "D" and points "C" and "B" will be half that of the battery voltage - which means the voltage between points "D" and "B" will be zero since they must be at the same voltage.
Putting it in an RF circuit:
Useful at DC, there's no reason why it couldn't be used at AC - or RF - as well. What, for example, would happen if we made R1, R2, and R3 the same value (let's say, 50 ohms), instead of using a battery, substituted a transmitter - and for the "unknown" value (Rx) connected our antenna?
Figure 3: The bridge, used in an antenna circuit.
This describes a typical RF bridge - known when placed between the transmitter and antenna as the "Tayloe" bridge, the simplified diagram of which being represented in Figure 3.
Clearly, if we used, as a stand-in for our antenna, a 50 ohm load, the RF Sensor will detect nothing at all as the bridge would be balanced, so it would make sense that a perfectly-matched 50 ohm antenna would be indistinguishable from a 50 ohm load. If the "antenna" were open or shorted, voltage would appear across the RF sensor and be detected - so you would be correct in presuming that this circuit could be used to tell when the antenna itself is matched. Further extending this idea, if your "Unknown antenna" were to include an antenna tuner, looking for the output of the RF sensor to go to zero would indicate that the antenna itself was properly matched.
At this point it's worth noting that this simple circuit cannot directly indicate the magnitude of mismatch (e.g. VSWR - but it can tell you when the antenna is matched: It is possible to do this with additional circuitry (as is done with many antenna analyzers) but for this simplest case, all we really care about is finding when our antenna is matched. (A somewhat similar circuit to that depicted in Figure 3 has been at the heart of many antenna analyzers for decades.)
Antenna match indication and radio protection:
An examination of the circuit of Figure 3 also reveals another interesting property of this circuit used in this manner: The transmitter itself can never see an infinite VSWR. For example, if the antenna is very low resistance, we will present about 33 ohms to the transmitter (e.g. the two 50 ohm resistors on the left side will be in parallel with the 50 ohm resistor on the right side) - which represents a VSWR of about 1.5:1. If you were to forget to connect an antenna at all, we end up with only the two resistors on the left being in series (100 ohms) so our worst-case VSWR would, in theory, be 2:1.
In context, any modern, well-designed transmitter will be able to tolerate even a 2.5:1 VSWR (probably higher) so this means that no matter what happens on the "antenna" side, the rig will never see a really high VSWR.
If modern rigs are supposed to have built-in VSWR protection, why does this matter?
One of the first places that the implementation of the "Tayloe" bridge was popularized was in the QRP (low power) community where transmitters have traditionally been very simple and lightweight - but that also means that they may lack any sophisticated protection circuit. Building a simple circuit like this into a small antenna tuner handily solves three problems: Tuning the antenna, being able to tell when the antenna is matched, and protecting the transmitter from high VSWR during the tuning process.
Even in a more modern radio with SWR protection there is good reason to do this. While one is supposed to turn down the transmitter's power when tuning an antenna, if you have an external, wide-range tuner and are quickly setting things up in the field, it would be easy to forget to do so. The way that most modern transmitter's SWR protection circuits work is by detecting the reflected power, and when it exceeds a certain value, it reduced the output power - but this measurement is not instantaneous: By the time you detect excess reflected power, the transmitter has already been exposed - if only for a fraction of a second - to a high VSWR, and it may be that that brief instant was enough to damage an output transistor.
In the "old" days of manual antenna tuners with variable capacitors and roller inductors, this may have not been as big a deal: In this case, the VSWR seen by the transmitter might not be able to change too quickly (assuming that the inductor and capacitors didn't have intermittent connections) but consider a modern, automatic antenna tuner full of relays: Each time the internal tuner configuration is changed to determine the match, these "hot-switched" relays will inevitably "glitch" the VSWR seen by the radio, and with modern tuners, this can occur many times a second - far faster than the internal VSWR protection can occur meaning that it can go from being low, with the transmitter at high power, to suddenly high VSWR before the power can be reduced, something that is potentially damaging to a radio's final amplifier.
While this may seem to be an unlikely situation, it's one that I have personally experienced in a moment of carelessness - and it put an abrupt end to the remote operation using that radio - but fortunately, another rig was at hand.
A high-power Tayloe bridge:
It can be argued that these days, the world is lousy with Tayloe bridges as they are seemingly found everywhere - particularly in the QRP world, but there are fewer of them that are intended to be used with a typical 100 watt mobile radio - but one such example may be seen below:
Figure 4: As-built high-power Tayloe bridge with a more sensible
bypass switch arrangement! This diagram was updated to include a
second LED to visually indicate extreme mismatches and provide another
clue as to when one is approaching a match.
Figure 4 shows a variation of the circuit in Figure 2, but it includes two other features: An RF detector, in the form of an LED (with RF rectifier) and a "bypass" switch, so that it would not need to be manually removed from the coax cable connection from the radio.
In this case, the 50 ohm resistors are thick-film, 50 watt units (about $3 each) which means that between the three of them, they are capable of handling the full power of the radio for at least a brief period. Suitable resistors may be found at the usual suppliers (Digi-Key, Mouser Electronics) and the devices that I used were Johanson P/N RHXH2Q050R0F4 (A link to the Mouser Electronics page is here) - but there is nothing special about these particular devices: Any 50-100 watt, TO-220 package, 50 ohm thick-film resistor with a tolerance of 5% or better could have been used, provided that its tab is insulated from the internal resistor itself (most are).
How it works:
Knowing the general theory behind the Wheatstone bridge, the main point of interest is the indicator, which is, in this case, an LED circuit placed across the middle of the bridge in lieu of the meter shown in Figure 1. Because RF is present across these two points - and because neither side of this indicator is ground-referenced, this circuit must "float" with respect to ground.
If we presume that there will be 25 volts across the circuit - which would be in the ballpark of 25 watts into a 2:1 VSWR - we see that the current through 2k could not exceed 25 mA - a reasonable current to light an LED. To rectify it, a 1N4148 diode - which is both cheap and suitably fast to rectify RF (a garden-variety 1N4000 series diodes is not recommended) along with a capacitor across the LED. An extra 2k LED is present to reduce the magnitude of the reverse voltage across the diode: Probably not necessary, bit I used it, anyway. QRP versions of this circuit often include a transformer to step up the low RF voltage to a level that is high enough to reliably drive the LED, but with 5-10 watts, minimum, this is simply not an issue.
Because the voltage across the bridge goes to zero when the source and load impedance are matched (or the switch is set to "bypass" mode) there is no need to switch the detector out of circuit but note that the LED and associated components are "hot" at RF when in "Measure" position which means that you should keep the leads for this circuit quite short and avoid the temptation to run long wires from one end of a large enclosure (like an antenna tuner) to the other as excess stray reactance can affect the operation of the circuit.
Note: See the end of this article for an updated/modified version with a second LED .
A more sensible bypass switch configuration:
While there are many examples of this sort of circuit - all of them with DPDT switches to bypass the circuit - every one that I saw wired the switch in such a way that if one were to be inadvertently transmitting while the switch was operated, there would be a brief instant when the transmitter was disconnected(presuming that the switch itself is a typical "break-before-make" - and almost all of them are!) that could expose the transmitter to a brief high VSWR transient. In Figure 3, this switch is wired differently:
When in "Bypass" mode, the "top" 50 ohm resistor is shorted out and the "ground" side of the circuit is lifted.
When in "Measure" mode, the switch across the "top" 50 ohm resistor is un-bridged and the bottom side of the circuit is grounded.
Figure 5: Inside the bridge, before the 2nd LED was added
Wired this way, there is no possible configuration during the operation of the switch where the transmitter will be exposed to an extraordinarily high VSWR - except, of course, if the antenna itself is has an extreme mismatch - which would happen no matter what if you were to switch to "bypass" mode.
An as-built example:
I built my circuit into a small die-cast aluminum box as shown in Figure 5. Inside the box, the 50 ohm resistors are bolted to the box itself using countersunk screws and heat-sink paste for thermal transfer. To accommodate the small size of the box, single-hole UHF connectors were used and the circuit itself was point-to-point wired within the box.
For the "bypass" switch (see Figure 6) I rescued a 120/240 volt DPDT switch from an old PC power supply, choosing it because it has a flat profile with a recessed handle with a slot: By filing a bevel around the square hole (which, itself was produced using the "drill-then-file" method) one may use a fingernail to switch the position. I chose the "flush handle" type of switch to reduce the probability of it accidentally being switched, but also to prevent the switch itself from being broken when it inevitably ends at the bottom of a box of other gear.
Figure 6: The "switch" side of the bridge.
On the other side of the box (Figure 7) the LED is nearly flush-mounted, secured initially with cyanoacrylate (e.g. "Super") glue - but later bolstered with some epoxy on the inside of the box.
It's worth noting that even though the resistors are rated for 50 watts, it's unlikely that even this much power will be output by the radio will approach that in the worst-case condition - but even if it does, the circuit is perfectly capable of handling 100 watts for a few seconds. The die-cast box itself, being quite small, has rather limited power dissipation on its own (10-15 watts continuous, at most) but it is perfectly capable of withstanding an "oops" or two if one forgets to turn down the power when tuning and dumps full power into it. It will, of course, not withstand 100 watts for very long - but you'll probably smell it before anything is too-badly damaged!
Operation:
As on might posit from the description, the operation of this bridge is as follows:
Place this device between the radio and the external tuner.
Turn the power of the radio down to 10-15 watts and select FM mode. You may also use AM as that should be limited to 20-25 watts of carrier when no audio is present.
Disable the radio's built-in tuner, if it has one.
If using a manual tuner, do an initial "rough" tuning to peak the receive noise, if possible.
Switch the unit to "Bridge" (e.g. "Measure") mode.
Key the transmitter.
If you are using an automatic tuner, start its auto-tune cycle. There should be enough power coming through the bridge for it to operate (most will work reliably down to at about 5 watts - which means that you'll need the 10-15 watts from the radio for this.)
If you are using a manual tuner, look at both its SWR meter (if it has one) and the LED brightness and adjust for minimum brightness/reflected power. A perfect match will result in the LED being completely extinguished.
After tuning is complete, switch to "Bypass" mode and commence normal operation.
* * *
Modification/enhancement
More recently (July, 2023) I made a slight modification to this bridge by adding a second
LED driven by the opposite swing of the RF waveform so that it would
not have any effect on the first - this LED designed to illuminate only under highly-mismatched conditions at higher power levels.
Figure 7: The "enhanced" version with TWO LEDs.
As seen in the Figure 7 (above) the "original" LED is now designated as being yellow (the different color allowing easy differentiation) - but the second LED - which indicates a worse condition - is
red and placed with a series 6.8 volt Zener diode (I used a 1N754A). The idea here is that if the VSWR is REALLY
bad and the power is high enough, BOTH LEDs will illuminate - but the
"new" (red) LED will go out first as you get "close-ish" to the match.
Figure 8: It has two LEDs now!
In testing with an open or short on the output and in "measure" mode the
red LED illuminated only above about 15 watts, so this second LED isn't
really too helpful for QRP unless the value of the 2k, 1 watt resistor
is reduced. Again, this isn't really to indicate the SWR, but having
this second, less-sensitive LED helps with the situation when using a
manual tuner in which the match is so bad that it's difficult to spot
subtle variations in the brightness of +the more sensitive (yellow) LED -
particularly at higher power levels.
The SatNOGS network has reached 5,000,000 observations and we are thrilled to share this news with you!
More specifically, on the 13th of November, Observation #5000000 was uploaded on the SatNOGS network from the 1126 – notch ground station in New Hampshire, USA. It was scheduled by user kc1ist and received data from satellite ACRUX-1.
And though the 5 millionth Observation was received from a satellite that is no longer active, still there are two interesting stories behind this observation that we would like to share with you. The first story revolves around the satellite ACRUX-1.
SatNOGS and ACRUX-1
Though nowadays, ACRUX-1 might be a “dead” satellite, the truth is that its story is not only fascinating but also indicative of the way the SatNOGS community operates. So let us take a closer look.
ACRUX-1, an Australian, university satellite, was launched at the end of June 2019. Upon deployment, the satellite was operating according to plan and for the first couple of days, everything was working fine. The TLEs had been released early on and the SatNOGS network was as usual, active and ready to track the satellite. But… after a few days of flying in space, ACRUX-1 went dead. And as the days passed and there was no signal received, everyone believed that that was the end for the satellite. The SatNOGS network though continued to keep an eye on ACRUX-1, by continuing to schedule observations.
It wasn’t until 5 months later, in December 2019, when a radio amateur picked up a signal of an “unknown” satellite and posted about it on Twitter https://twitter.com/CX8AF/status/1200969150094618624. A member of the SatNOGS network came across that tweet and recognised the “unknown” satellite. It was, in fact, ACRUX-1, that had begun transmitting again. The network was notified and it began tracking the satellite that inevitably became a priority. SatNOGS started receiving and collecting data about it!! ACRUX-1 was “resurrected” after almost 5 months and its signal was live again. Sadly, that transmission lasted only a couple of hours. One thing to note is that during its “resurrection”, the satellite transmitted in a different frequency than the one in the first place. And though the communication upon resurrection was maintained only for a few hours, the entire process was exciting to follow and monitor.
Before becoming Observation 5M, ACRUX-1 had numerous observations including Observation #1296318 scheduled back in December 2019, during its few hours of “resurrection”.
SatNOGS and the Hackaday Prize
Observation #5000000 was received on a day that is of great significance for SatNOGS. As years ago, on the 13th of November 2014 SatNOGS won the Hackaday Prize, and officially kick-started Libre Space Foundation. Since then and with the continuous help of the diverse community that supports us, SatNOGS has expanded and evolved into a global network, boasting amazing statistics.
More specifically, at present, the SatNOGS network counts over 260+ fully operational ground stations and 120+ in testing mode. The observations come from 710+ satellites and 1340 transmitters having delivered over 122M data frames.
We could not have done this without you!
As is the case with all the amazing milestones that SatNOGS has reached, this too is a result of the collaborative work and the continuous efforts made by hundreds of ground station owners around the globe. They are the ones who contribute to this milestone and to the success of the SatNOGS project itself. By investing their time and effort in this, they schedule, organise and perform satellite observations. It is because of the community and its members that SatNOGS has expanded greatly and has become the biggest collaborative, dynamic, global, open-source network of satellite ground stations.
Do you want to join our community and learn about open-source space technologies?
We always welcome people from around the globe who wish to contribute their time, knowledge and expertise to our projects. If you are interested in joining us check out the SatNOGS knowledge-base wiki and feel free to drop us a line on the community forums and our chat. We would love to hear from you and have you onboard the SatNOGS network and community. Join SatNOGS now and be part of the next million observations!
We are thrilled to have reached 5M observations and we are also grateful to be celebrating it with all of you. All the SatNOGS contributors, satellite operators, radio amateurs, space enthusiasts, university and scientific teams. It is because of you that SatNOGS keeps expanding and growing. Thank you.
After trying and failing at getting a working APRS set-up with voice alert here is my last try with a CRT 2M Radio, a rebranded Anytone AT588. Disclaimer Just the usual stuff here : if …
As is the case with all the amazing milestones that SatNOGS has reached, this too is a result of the collaborative work and the continuous efforts made by hundreds of ground station owners around the globe. They are the ones who contribute to this milestone and to the success of the SatNOGS project itself. By investing their time and effort in this, they schedule, organise and perform satellite observations. It is because of the community and its members that SatNOGS has expanded greatly and has become the biggest collaborative, dynamic, global, open-source network of satellite ground stations.
Interesting Statistics
The SatNOGS network counts over 260+ fully operational ground stations and 140+ in testing mode. The observations come from 580+ satellites and 1140+ transmitters having delivered over 100.000.000 data frames.
Do you want to join our community and be part of the next million observations?
We always welcome people who wish to contribute their time, knowledge and expertise to our projects. If you are interested in joining us check out the SatNOGS knowledge-base wiki, and feel free to drop us a line on the community forums and our chat. We would love to hear from you and have you onboard the SatNOGS network and community. Join SatNOGS now!
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