Inmarsat Software Defined Radio Pdf

A subreddit for the low-cost, DIY software defined radio (SDR) community. While originally dedicated just to the project, relevant legal content related to general SDR, RF and similar projects is also welcomed.

Feel free to ask questions but please. Rtl-sdr 'rtl-sdr' is a generic term for cheap USB digital TV (DVB-T) receivers that use the Realtek RTL2832U chipset, which can function as general purpose software defined radios (receive only). All rtl-sdr compatible devices employ the RTL2832U as an ADC and USB controller, but different RF tuners may be used. Note that rtl-sdrs do not transmit! Typical specs (some depend on specific tuner): • Cost: ~$5-45 USD • Frequency range: 24 - >1760 MHz (100 KHz - 24 MHz in direct sampling mode) • Max sample rate: 3.2 MS/s (2.6 MS/s in practice) • Resolution: 8 bits/sample • Noise figure. Hey I wrote the article.

I used an R820T2. The ambient temperature here when I tested was about 16-17 degrees celcius. I knew about the temperature issues so I tested it with the dongle insulated in some heavy fabric and reception failed after about 30 - 60 minutes. Also failed after the same time when running in direct sunlight.

When running in the shadows it ran indefinitely. I also tried an R820T but it was almost useless that high - it worked fine for about 1 minute then failed to RX at 1.5 GHz any more once the dongle warmed up very slightly. I'll edit the article to make a bigger point of the temperature issue, thanks for bringing it up. I think that they got the idea from one of youtube video where the guy is using commercial equipment and testing setup with one adn two LNAs. Beside the dongle issues, the most important thing is not explained: antenna. Modifying GPS antenna with 2 LNA stages on backside gave not so good result. Well, what can be expected from the tiny patch antenna.

Better results obtained from the L band patch antenna (part of the future Outernet) where aperture is bigger hence the bigger gain. From the photo attached I can see the patch masked with the protection (most probably copyright:-)) but the trimmed corners to obtain RHCP are too big. Important: if you want to play with the GPS, Inmarsat, Iridium on the L band use the RHCP (righ hand circular polarization) for the antenna, and the LHCP for the Thuraya. With the patch antenna you can get the 9dbi (max) for one patch.

As there are no measures publicated, for everyday user it may be difficult to build the patch antenna but less troubles may be making RHCP helix antenna with let say 25 turns and 15dBi gain. This will bring your signal out of the noise and one LNA will be enough. As the inmarsta satellites are geostacionary, a tv dish antenna may be used, again with the helix feed, but only 2 turns and LHCP!! Due to changing pol. Because of the dish miror. At the end, using downconverter may open your eyes and bring another dimension to the dongle.

Yeah I got the idea from that video, plus stories on how some people were using GPS antennas to receive Iridium pagers. Outernet sent me a sample patch antenna and I was looking for ways to test it, since their service is not running yet. The GPS antenna is I think, just on the edge of being able to decode the NCS channel with an RTL-SDR (it is better with the Airspy). But as I see some GPS antennas on eBay for under $4 shipped, I think it is worth a shot if you just want to give it a try. Mentioning the helix antenna is a good point, i'll put in some links in the article for helix antenna builds.

I got permission to post pictures of the air gap patch from Outernet. I can take some more pictures if you want?

GMDSS GUIDE 14073SK Printed in. The coverage of Inmarsat geostationary satellites. Sea Area Area outside A1, A2 and. (VHF) Coast Radio Station Medium Frequency (MF). A subreddit for the low-cost, DIY software defined radio (SDR) community. While originally dedicated just to the rtl-sdr project, relevant legal content related to.

With the patch one LNA was enough with a short coax cable. Outernet is apparently working on a downconverter LNB, and I think someone here was too (was it you?). A downconverter will make the RTL much better at receiving L-band. The article will be nice, when you add the extra informations you have. The outernet guys are taking advice and thats good. The patch antenna and downconverter was proposed here by me on some post earlier and this can be way to go. It should be interesting to see how they plan to make the LNB.

Yep, I am also working on LNB for the L band. Proof of the project done, now designing the fist all in one pcb prototype but the new ideas are just poping out and constant upgrading on the project:-) It is easy to build the project with unlimited funds but more chalenge to get the same results with limited funds. Thanks for the infos and the web site you are keeping live and interesting. In series means in series:-) what else.

You connect the first one and after that the second one. One after other. Total gain will be gain of the first + gain of the second LNA. From the active GPS antenna picture I can recognise the two 2SC5508 or NE662M04 (depending on the manufacturer) transistors and the GPS filter in the center. Estimated gain of each is around 16-17dB and the NF 1dB.

They are rated to work over the 2GHz but modifying the GPS antenna I expect you can get usable range from 1-2GHz.

On YouTube has posted a tutorial video on how to receive, decode and plot AIS information. The is a system used for automatic tracking of large ships and passenger boats.

It is a similar idea to tracking aircraft with ADS-B. His method uses a RTL-SDR for receiving the AIS signals with SDRSharp, decoding received signals with AISMon and plotting the decoded information with OpenCPN. He uses VB-Cable for looping the audio from SDRSharp to AISMon, but if you have a ‘Stereo Mix’ or equivalent feature with your soundcard, that will be unneeded. Best results will be achieved using a narrow-band vertically polarized antenna tuned for 161.975 MHz and 162.025 MHz (marine VHF).

A directional antenna would also likely be a benefit. You can find some designs to try lower down the page. For safety, please only use this guide on land!

Wouldn’t want you getting lost at sea. Here are the homepages of the software used: • • – You may need to first join the group with a Yahoo account to gain access to the file section. • • (for looping audio from SDRSharp to AISMON) Below is a screenshot of OpenCPN in action: Here are some antennas designed for AIS reception: • • • • or any antenna tuned to ~162MHz For a tutorial with other software, check out the page at rtl-sdr.com.

For more than 50 years the National Oceanic and Atmospheric Administration’s weather satellites have been helping monitor the earth’s weather patterns. Now over on YouTube (IZ5RZR) has on how you can receive images from the NOAA (NOAA-9, NOAA-15, NOAA-18, NOAA-19) at home using an RTL-SDR. He gives a full walk through of using Orbitron to track the satellites, WXtoImg to decode received images and using SDRSharp to tune your RTL-SDR. He also suggests building and using a QFH Antenna or Turnstile Antenna with your RTL-SDR to receive the satellites. Here is a list of programs used and homepage links: • • • If you’re looking for some antenna designs, check out: • • • • • Here is an example of and image you could receive: UPDATE: Jordan Jean-Philippe Blanchard has shared a link on the to his setup for receiving the weather satellite images using an RTL-SDR, &.

Travis Goodspeed has shared a project about his adventure in tracking low orbit satellites using a fairly complex setup. He is using a dish intended for connecting to one of the Inmarsat satellites while at sea on a maritime vessel, a EiBotBoard connected to a BeagleBone for motor control and a RTL-SDR for receiving radio signals from the dish. His goal has been to track the whole sky, including moving targets and it looks like he has been pretty successful. “ At Black Hat DC in 2008, I watched Adam Laurie present a tool for mapping Ku-band satellite downlinks, which he has since rewritten as. His technique involves using an DVB-S card in a Linux computer as a receiver through a 90cm Ku-band dish with fixed elevation and a DiSEqC motor for azimuth motion. It was among the most inspirational talks I’d ever seen, and I had a blast recreating his setup and scanning the friendly skies. However, such a rig is limited to geostationary satellites in a small region of the sky; I wanted to see the whole sky, especially the moving targets.

In this article, I’ll demonstrate a method for modifying a naval telecommunications dish to track moving targets in the sky, such as those in Low Earth Orbit. My dish happily sits in Tennessee, while I direct it using my laptop or cellphone here in Europe. It can also run unattended, tracking moving targets and looking for downlink channels.” — via. Over on the, Boris Lukac has to an Instructable by for a omnidirectional fractal HDTV antenna.

The simple build covers 50-1100MHz making it perfect for general use with a RTL-SDR and for grabbing some extra HDTV channels when not hooked up to your dongle. “I have been getting into software defined radio via and found the stock antennas woeful for reception and picked up a tonne of noise from my LCD and laptop – though it’s hardly surprising. So to improve the situation and spend as little as possible I decided to make a antenna. Film Tinkerbell Secret Of The Wings Sub Indo Hwa. After some research I happened upon VE3SQB’s and a neat discone design for Windows.

As a compromise between frequency and unwieldyness I settled on 130MHz as the lower bound. Discones are inherently wideband and I expect the antenna to be useful for reception in the 60MHz to 1700MHz band the E4000 tuner can work with.” —.