Tagged: NOAA

Raspberry NOAA V2 Edition 2023 Image Released

Thank you to Manuel Lausmann for submitting news about the release of the "Raspberry NOAA V2 Edition 2023" image for Raspberry Pi's. This image has been created by Jochen Köster (DC9DD), and contains a few enhancements over the previous image, mainly by including a program that allows users to create composite images of images from the Meteor weather satellites. Manuel writes:

This is based on the well-known Raspberry Noaa V2. In this image, however, the latest MeteorDemod has been added, which makes it possible to generate composite images, which was previously only possible under Windows with Meteorgis.

Furthermore, the image has an additional FTP uploader. The image was created by Jochen Köster DC9DD. It's available from today. This image is also part of my off-grid station in Northern Norway.

Download link for the image: https://www.qsl.net/do3mla/raspberry-pi-images.html

Here is a link to the Facebook group for the image: https://www.facebook.com/groups/raspberrynoaav2edition

Here is a link to ranged from my off-grid station where this image is running: https://usradioguy.com/science/off-grid-apt-lrpt-satellite-ground-station

An example of a composite image from multiple Meteor satellite images.

More Information about the NOAA-15 AVHRR Failure

Thank you to Carl Reinmann (aka usradioguy) for submitting his blog post which goes into deeper detail about the NOAA-15 weather satellite imaging failure that we posted about last week. 

In his post Carl discusses in detail the technical aspects of the AVHRR Scan Motor failure, shows plots of the AVHRR motor current increasing, provides multiple examples of corrupt images being recently received and notes the history of previous failures which were eventually resolved.

He also notes that even with the AVHRR failure the other sensors on the satellite will remain functional, however a failure of this instrument would mean the end of the easy to receive APT images at 137 MHz from NOAA-15. We note that there is still the opportunity to receive NOAA-18 and NOAA-19 which are the remaining operational satellites that transmit APT at 137 MHz.

NOAA have now also released an official notice about the failure which reads:

Product Outage/Anomaly: NOAA-15 AVHRR degraded image data issued by NESDIS NSOF
Date/Time Issued: Oct 22, 2022 1947Z

The NOAA-15 AVHRR Scan Motor current began showing signs of instability on Oct 18 at approximately 1800Z, when the current began to gradually rise from about 205 mA to about 250 mA, where it remained until Oct 24. At about 0000Z on Oct 24, the current began rising again throughout the day, peaking at about 302mA on Oct 25. Scan motor temperature began rising about the same time and is currently steady at ~29°C. The instrument is still producing data, but it is highly degraded. This behavior may be a sign of an impending scan motor stall but requires further investigation. Options for recovery are limited.

NOAA-15 Scan Motor Failure

The NOAA-15 Weather Satellite may be Failing (Again)

The NOAA APT weather satellites are popular because they fly over most places on earth frequently, and they are easy to receive images directly from with modest hardware such as an RTL-SDR and v-dipole antenna.

Three NOAA APT satellites currently operational include NOAA-15, NOAA-18 and NOAA-19. The satellites are however long past their rated mission age, with NOAA-15 being almost 25 years old now.

Unfortunately NOAA-15 appears to be having trouble with it's image scanning motor at the moment, and it is producing corrupted images. This problem has occurred in the past in 2018 and 2019, before fixing itself, so the hope is that it will fix itself again this time.

NOAA does not appear to have released any information about the outage yet on their General Satellite Messages page.

We also wanted to note the recent news that NOAA will be transitioning NOAA-15, 18 and 19 to a private company for on-orbit operations.

SatDump ReWork Release with Significant Feature and GUI Updates

SatDump is a popular piece of software that can be used with RTL-SDRs and other software defined radios for decoding images from a wide array of weather imaging satellites including GOES, GK-2A, NOAA HRPT, FengYun, Electro-L and Meteor M2 LRPT + HRPT, and many others (note: there is no APT support at the moment, but it is planned for the future). It is compatible with Windows, Linux and even has an Android APK available.

Recently author @aang23 has updated the software, noting that he's done an almost full rewrite, including major updates to the GUI. The SatDump blog post goes into greater detail about he updates, but as a summary some of the biggest updates include:

  • A reworking and tidy up of the GUI with improved FFT view
  • A viewer which allows you to view output image products, and create RGB composites
  • A projection tool on the viewer, allowing you to project images onto OpenStreetMap.
  • Upgrades to the plugins system, allowing developers to more easily add support for new satellites / missions and SDRs.
  • The addition of 'products' metadata, allowing users to separate raw channel data
  • The addition of demodulators like DVB-S2, GOES-R GRB, HimawariCast, DVB-S
  • Support for additional SDRs like BladeRF, SDRplay RSP Duo, PlutoSDR and MiriSDRs.
  • Updates to the CLI interface
  • Updated less buggy Android App
SatDump new Live Decoding / Recorder Interface

Tracking and Decoding Guide for NOAA Weather Satellites

Thank you to Samual Yanz (N7FNV) for submitting a guide that he's created about tracking and decoding NOAA weather satellites. The guide can be downloaded from this link as a PDF. 

Currently there are three operational polar orbiting NOAA weather satellites that transmit image data in the APT format at 137 MHz. When one of these satellites pass overhead, it is possible to use an RTL-SDR with appropriate satellite antenna and software to receive the satellite weather images they transmit.

Samual's guide focuses on the software and shows how to setup Virtual Audio Cable for piping audio between programs, SDR# for receiving the signal, Orbitron for tracking the satellite and WXtoIMG for decoding the image.

SDR#, Orbitron and WXtoIMG

Open-Weather: A Browser Based NOAA APT Satellite Image Decoder

Thank you to Sasha Engelmann for letting us know about the release of the Open-Weather community's web browser based NOAA APT decoder. The decoder allows for easy NOAA satellite decoding by allowing you to upload a wav file recording of a NOAA satellite pass, and it will decode it into an image within the browser. 

The project emerged from a desire to understand the process of decoding APT audio recordings into NOAA satellite images, and a need for an accessible browser-based decoder for new practitioners during open-weather DIY Satellite Ground Station workshops.

While we were inspired by Thatcher's APT 3000, we felt accessibility, documentation and features could be expanded and improved. open-weather apt allows you to select an audio file on your computer, choose a demodulation method, add histogram equalisation and download images. The website does not store your personal data, including your location or any files you upload.

Documentation of the decoder is available on Public Lab here: https://publiclab.org/notes/sashae/05-03-2022/an-accessible-browser-based-decoder-for-noaa-images

open-weather apt is forked from Thatcher's APT 3000. It is a collaboration between open-weather, Bill Liles NQ6Z and Grayson Earle.
Open-weather web based APT decoder

An off-grid wind and solar powered APT/LRPT satellite image receiver with RTL-SDR

Over on the usradioguy.com blog, Carl Reinemann has highlighted a very impressive remote off-grid radio satellite image receiver setup by Manuel Lausmann (DO3MLA). The setup consists of two Raspberry Pi's, two RTL-SDRs and a QFH satellite antenna connected to an antenna splitter and bias tee. It is able to receive APT and LRPT images from NOAA and Meteor satellites which transmit at 137 MHz. The received images are then uploaded to the internet via a mobile LTE router.

The system is located a remote part of Northern Norway and is powered by a dual solar and wind turbine system with battery storage. Being so remote with little interference, the system is able to receive very clean images, and with the location being so Northern, it can even glimpse the north pole.

Manuel has uploaded a YouTube video where he shows each part of the system. It is in narrated in German, however the YouTube caption auto translate feature can be used.

He notes that in the future he hopes to install a web SDR like KiwiSDR on the site too.

Autarkstation für Funkanwendungen

APT_COLOR: Add False Color to Black and White NOAA APT Images

Thank you to Sasha for submitting news about the release of their latest application called "apt_color". The most popular application for decoding APT weather satellite images from NOAA polar orbiting satellites is WXtoIMG. However, WXtoIMG is closed source and is abandonware. There are APT decoder alternatives, however unlike WXtoIMG most other open source APT decoders only provide black and white images, and do not have a false color feature.

The apt_color application can be used to turn black and white APT images received from NOAA satellites into false color images. Sasha writes:

I am working on an APT false color application here. The application is still in the very, very, early stages but still seems to produce good results. It does not need to rely on any overlays, it simply works off the data you give it - the original decoded image data. I will attach some results. NOAA-18 seems to be the best suited spacecraft for this program.

apt_color: Turn black and white NOAA images into false color
apt_color: Examples