Brother James, you had to see this coming. I actually don't think it would be a bad thing. If this already exists, please point me in the right direction. Now then, buckle up, this is going to be epic! So let's begin.... I would like to commission a very unique author for a very unique project. The goal of that project being, making me less dumb enough so that my questions might make sense. Easy Peasy! This author can't just be anyone, no Nicholas Sparks isn't right. Not only does this author need to be capable of writing in very detailed fashion, (s)he needs to be able to do so at the level of an 8 year old! I know, FUN, right?!?! But there is one last requirement, and this one is a doozy. This author must have, like a ridiculously comprehensive and granular level understanding of the inner workings, conceptual theories, and systemic understanding, no, expertise, like James-level expertise, in all things SDR, and preferably all things ADS-B, and even more preferably, all things Raspberry Pi. So, for the purposes of this exercise, let's suppose that for this SDR application we will be running the RTL-SDR v3 off of a Raspberry Pi 4 (2GB RAM) board, both of which are fully enclosed inside of a modified Argon40 M.2 case. The RasPi4 is running the stock version of the most recent release of the only software I would dare mention in these confines, the ADS-B Exchange Custom Pi Image Aircraft ADS-B feeder software, and are doing so in a headless configuration. To understand my need for this book, I want to quickly run you through what I call now my journey of enlightenment, to say the least. This occurred over the previous few months in an effort to gain a comprehensive understanding of exactly how these SDRs work and what components are controlling each function or process. I went completely off the tracks based on some ambiguous statements I read on a few SDR manufacturer websites, and as luck would have it, misconstrued some other evidence which erroneously provided validation of the flawed understanding of the SDR's operation, a frustrating realization to have. The crux of this inaccurate understanding was that I thought that these small dongle-tier SDRs (such as the RTL-SDR and Nooelec Nano 3) needed to be preprogrammed for the application I would be using them for, which in this case was 1090MHz. I won't delve into how I arrived at this conclusion because those details aren't relevant for this question, and I do not want to sound as if I'm blaming any source or website for my failings. Suffice to say, I spent more than a few hours trying every free SDR configuration software program I could find, but could not find the function that would allow me to preprogram the SDR to 1090MHz. So I went to the forums, and luckily, one kind individual replied with a response that represented that awful feeling which is the polar opposite of an exciting epiphany. At first, still perceiving his response behind the mind block caused by my severely flawed certainty, I interpreted his response as irrelevant and not addressing the question. I finally realized that I had committed a very common and easily avoided logical fallacy, one I have actually been formally trained to identify and avoid referred to as "Hasty Generalization". So, basically I had to start from square one, and made some headway, have a better conceptual understanding of which components in my ADS-B receiver setup are responsible for certain functions, but I have yet to find what I was truly looking for, which I feel would be worth a hundred books and forum posts if someone smarter than I could put it together. Which brings me to the exciting part of this post, where I beg and plead for someone to write a narrative, complete with basic illustrations, which walks the reader through every single step a signal takes along it's route. The name of this book will be "Mr. RF's Magical Journey Into the Cloud" I would like this story to begin at the very moment our main protagonist, Mr. RF, who just so happens to be a strapping 1090MHz (analog?) RF signal, is suddenly transmitted out from an aircraft's transponder antenna. What are some of the issues Mr. RF might encounter, issues that us budding SDRers should really know about, and then we follow Mr. RF as he is caught by an antenna that just so happens to be directly intersecting his trajectory, and also just so happens to designed specifically for Mr. RF's 1090MHz frequency, SWELL!. I know that antennas can be and are optimized for certain frequencies, but it would be tremendously helpful to learn how this is accomplished, and what the effects are on Mr. RF during this part of his journey. What is different for that Mr. RF as it propagates down an optimized antenna as opposed his experience had he instead been intercepted by a bent cloths hangar? Then Mr. RF emerges from the antenna's base and starts his exciting trek down the long skinny coax tunnel. But just after he entered, Mr. RF encounters a SAW filter, or a bandpass filter, or an amplifier, maybe all, maybe the one that should actually be there but I just don't know. After all this Mr. RF, I believe still in his OG analog form, but probably more isolated and way stronger based on those encounters in the coax tunnel, finally at the end of the tunnel, and realizes that he has arrived at the input of the SDR. I know there are multiple chip-sets in the SDR and multiple processes that occur, but that's it. I would love to hear the detailed process this modest analog signal undergoes, what order, why that order, and exactly what Mr. RF looks like when he exits the SDR output as a digital data signal. I don't understand what that looks like conceptually though. Does the SDR do any sort of data pre-processing so it exits as a data packet, or is it still an unprocessed digital version of what it once was in analog? Not looking for answers here, just seeding the lucky author's creative flow. Finally, Mr RF arrives (in my setup via a USB 3.0 U connection) into the Raspberry Pi 4 where I know the heavy lift portion of the processing occurs, after which the the ADS-B Exchange Custom Pi Image software packages it up with a few (hundred? thousand) other formatted data segments into a nice and tidy data packet, and shoots it up into the cloud at the speed of light, + or - a latent network switch or two along the way. Maybe at the beginning, or wherever it works best, there should also be a separate section which is similar to the last, but which walks the readers through each of the relevant processes that occur when the power is switched on and the the ADS-B Exchange Custom Pi Image begins running through it's boot-up scripts. I still don't truly understand the relationship the controlling software/ CPU have with the upstream SDR. The software defines the SDR's operational configurations by it's very definition,(nod to Brother James) but what does this look like? Does the software assign the 1090MHz frequency to the SDR just once at the beginning of the boot-up sequence and trust that the message was received and the instructions followed, all in the blind? Or do the components continually communicate back and forth in perpetuity for the entire time the power is applied and the data is flowing? Do they keep each other honest, or maybe one, probably the RasPi, monitors the SDR's processing integrity in some fashion, or are those types of RAIM-like systems reserved for air traffic navigation systems? All that and we are now circling right back to my original, question. I don't yet know, but I feel safe in assuming that if desired, one could hotwire the the ADS-B Exchange Custom Pi Image software (aka configure) to send a command to the SDR to toggle the bias-T function on. When does this occur? Does the SDR let the the ADS-B Exchange Custom Pi Image know that the message was received, "I did it, boss"? Or is the software, again simply sending commands in the blind without confirming that the SDR is in fact having a nominal enough day to comply with such a command? I know, this is the request of not just a next level nerd, but a next level NEEDY nerd! I won't argue or disagree, but I will not believe for one nano-second, that I would be the only bone-head in this galaxy, world, or forum who would find a tremendous amount of educational value in being able to read, and re-read, a heart warming story about our favorite signal in the whole world, Mr. RF, and all about his epic journey from the abyss of the National Airspace System, and all the way to the cloud. And hell yes, it needs to written for an 8 year old because that would be fantastic... Maybe 7....7 1/2 year old.... Yeah.. If there is the right author out there, and (s)he is someone who reads this forum post and actually writes us this book, I will, for no commission or fee, act as their publishing agent, have their Pulitzer Prize winning example of literary art translated into every language except Persian (Dang Dept. of Commerce Export Laws), and have them distributed so widely that these books will be piled high on every one of the shelves of..... of every Amazon Last Mile Distribution Center in the galaxy (Except Iran, sorry guys), and that person will be loved by all, including me, and maybe even the Iranians who will have obviously smuggled thousands of copies into their country, sanctions be damned!!! That person will be, the hero of the day! Good day, and may God have mercy on your soul....
I'm not worried..... jussst a matter of time...... Ye with patience is rewarded with... what he;s looking for....That didn't really work like I had hoped. annny minute
