Tagged: APT

Creating An Automated Raspberry Pi and RTL-SDR Based NOAA Weather Satellite Station

The nootropicdesign blog has recently uploaded a comprehensive tutorial showing how to create an automated NOAA Weather Satellite ground station using an RTL-SDR V3 and an Raspberry Pi 3. The project also makes use of an Amazon S3 bucket, which is a cheap web storage platform that allows you to store and access the downloaded images.

The tutorial starts by showing you how to set up your Amazon AWS credentials and bucket on the Raspberry Pi, and how to host a simple webpage that can be accessed publicly. The second stage shows how to set up the RTL-SDR drivers and wxtoimg which is used to decode the images. Finally, the third stage shows how to create the automation scripts that automatically schedule a decode, and upload images to the AWS bucket.

Flowgraph for an automated NOAA satellite weather image station.
Flowgraph for an automated NOAA satellite weather image station.

r2Cloud: Software for Automatically Decoding APT/LRPT Weather Satellites and Cubesats on a Raspberry Pi with RTL-SDR

Thanks to a tweet by @rf_hacking we recently came across an interesting project called "r2cloud". This is an open source program provided on a ready to use image for the Raspberry Pi that can be used to set up an automated satellite recording station for NOAA APT and Meteor LRPT signals, as well as for CubeSats.

The software presents a web based user interface that is easy to setup and view decoded images on. It appears that the software also communicates with a public server that can aggregate and log your data, and also provide it to SatNOGS and provide FunCube satellite telemetry to FunCube Warehouse.

Block Diagram for the r2cloud software.
Block Diagram for the r2cloud software.

Hackaday Article about the Slow Death of NOAA-15

If you've been following our blog, or have your own RTL-SDR based weather satellite station, then you'll know that the NOAA-15 APT satellite has been experiencing issues lately. There appear to be problems with it's camera scan motor resulting from it running low on lubrication. This is fully understandable as the satellite is 21 years old and well past it's expected life span. The satellite appears to be working some days, and producing garbage image other days.

Over on Hackaday, Dan Maloney has uploaded an interesting article that explores the history and technology behind NOAA-15's camera, and why it is now failing.

When NOAA-15 fails for good, don't feel too bad as we still have NOAA-18 and NOAA-19, the Russian Meteor M2, and Meteor M2-2 satellites, and the GOES satellites, all of which can be received by an RTL-SDR. Several new weather satellites are also planned for 2020 and onwards.

NOAA-APT Software Decoder: Users Guide Now Available

Back in August, 2018 we posted about NOAA-APT, which back then was a new NOAA APT image decoder program. Recently Martin, the author of NOAA-APT has written in and wanted to note that he's now created a guide and video tutorials for his software, and for NOAA APT reception in general.

NOAA weather satellites broadcast an Automatic Picture Transmission (APT) signal, which contains a live weather image of your area. With an RTL-SDR and antenna they can be received and downloaded every time one of the satellite's passes overhead which could be multiple times a day.

Our standard NOAA weather satellite tutorial makes use of SDR#, audio piping and the WXtoIMG to receive NOAA satellite images. Martin's guide and software might be slightly easier for newbies as it only involves recording an audio WAV file, then loading it up into his software. The disadvantage is that the image is not colorized, and not displayed in real time as it is in WXtoIMG.

As you may already know, the old standard software in NOAA image decoding, WXtoIMG, is now considered abandonware, and the only place to get it is from a third party mirror rehosting the now defunct WXtoIMG website. As WXtoIMG is closed source no further development can occur on it. Martin's NOAA-APT still misses a lot of the advanced features of WXtoIMG but it is fully open source and multiplatform, and so it is a very promising program.

Receiving NOAA satellite images with noaa-apt and SDR#

New NOAA APT Image Decoder

Over on GitHub user martinber has released a new NOAA APT image decoder that can run on both Linux and Windows. The decoder is called noaa-apt and takes a .WAV file of a NOAA satellite pass, and turns it into an image file. The .WAV file can be recorded in any SDR program like SDR#, HDSDR, GQRX etc.  The program is programmed in Rust, and has ready to run binaries available for both Linux and Windows available on it's GitHub Releases page.

Compared to the features found in WXtoIMG the software is fairly basic, but as WXtoIMG has been abandoned it's good to see new APT decoders still being worked on. The software can also be used to simply resample the .WAV file into a sample rate required by other more featured decoders like aptdec.

NOAA weather satellites broadcast an Automatic Picture Transmission (APT) signal, which contains a live weather image of your area. With an RTL-SDR and antenna they can be received and downloaded every time one of the satellite's passes overhead. We have a tutorial on using an RTL-SDR with WXtoIMG available here.

NOAA-APT: NOAA APT Weather Satellite Image Decoder
NOAA-APT: NOAA APT Weather Satellite Image Decoder

Building a Tracking Mount for HRPT Weather Satellite Reception Part 2

Earlier this month we posted about The Thought Emporium who uploaded a video to YouTube where they documented the first steps of their construction of a tracking mount for a 2.4 GHz grid WiFi dish which they intend to use for HRPT weather satellite reception.

If you didn't already know, receiving HRPT weather satellite signals is a little different to the more commonly received NOAA APT or Meteor M2 LRPT images which most readers may already be familiar with. HRPT is broadcast by the same NOAA satellites that provide the APT signal at 137 MHz, but is found in the L-band at around 1.7 GHz. The signal is much weaker, so a high gain dish antenna with motorized tracking mount, LNA and high bandwidth SDR like an Airspy is required. The payoff is that HRPT images are much higher in resolution compared to APT.

In this video they document the steps required to finish the physical build and add the electronics and motors required to control and move the dish. The final product is a working tracking mount that should be able to track the NOAA satellites as they pass over. In the next video which is not yet released they plan to actually test reception.

DIY Satellite Tracker/Radio Telescope - Part 2

Building a Tracking Mount for HRPT Weather Satellite Reception

Over on YouTube channel The Thought Emporium recently released a new video where they show the first steps they've taken towards building a home made satellite tracking mount for receiving HRIT and HRPT low earth orbit weather satellites. In their build they use a 2.4 GHz WiFi parabolic grid antenna, gears and mounts made from milled wood, and some metal supports. The build is not yet finished, but they intend to show their progress in future videos. Note that we're not confident that the 2.4 GHz grid antenna will actually work for them. In the past people have had success with 1.9 GHz Grid antennas however.

If you didn't already know, receiving HRPT weather satellite signals is a little different to the more commonly received NOAA APT or Meteor M2 LRPT images which most readers may already be familiar with. HRPT is broadcast by the same NOAA satellites that provide the APT signal at 137 MHz, but is found in the L-band at around 1.7 GHz. The signal is much weaker, so a high gain dish antenna with motorized tracking mount, LNA and high bandwidth SDR like an Airspy is required. The payoff is that HRPT images are much higher in resolution compared to APT.

Actually, it's not entirely true that a tracking mount is required, although it certainly makes things easier. We've seen in the past that 'Tysonpower' was able to receive HRPT by tracking his dish by hand.

The Thought Emporium also note that they hope to use their tracking mount in the future for other purposes like amateur radio astronomy. In one of their previous experiments they've build a smaller version which was able to create a heat map of WiFi signal strengths in their area.

Building a Motorized Satellite Tracker for HRIT/HRPT Reception and Radio Astronomy - Part 1

New Alternative WxToImg Website with Most Files

Last month we posted that the website for the popular NOAA APT weather satellite decoding software known as WxtoImg went down. Since then we've been in contact with the developer of the software, and he did indicate that he may restore the site at some time in the future, but is currently busy with other projects so doesn't have much time to devote to his old software at the moment.

In the meantime (or perhaps permanently) a WXtoImg fan has created a clone of the original website which he's called "WXtoImg Restored". The site contains most of the downloads as well as a professional edition update key, which was released for free by the original author before. If you don't trust the third party site, some downloads are also still available from the internet archival project's copies of the original WXtoImg website.

There are still some files missing on WXtoImg Restored, and these are outlined on the new website's homepage, so if you have them please contribute them to the site email.