As part of his Masters in Design Studies studies Daniel Tompkins created an art installation called "signs of life" which was focused around his interest in weather satellite reception with an SDR.
FM radio headphones were given out at the door. Each set was tuned beforehand to receive a broadcast from my pre-programmed station.
Visitors were then invited to walk around the room, contemplating the artifacts of the exhibit. A V-dipole at one end of the room captures the broadcast and displays a real-time spectrogram of the radio waves on a small display.
Across the room, a satellite dish points back, creating an alignment across the projected GOES-16 "full-disk" image animation of the Earth. Along the back wall, a few dozen images show demodulated signals from the NOAA 15/18/19 satellites as they passed over Cambridge, Massachusetts in the months of October and November 2018.
The experience demonstrated my interest in tapping into an invisible (wireless) environment of digital information. A USB, software-defined radio (SDR) dongle helped me reach the satellites.
In listening to the transmission, the visitors are engaging in a shared experience, but are somehow still alone and unable to communicate while wearing their headphones. The performance of the exhibition is designed to be a place which simulates the real disconnection of techno-humanity. The "reﬂecting pool" of the earth spinning on the ﬂoor might provide a metaphorical reﬂection of humanity and progress.
This installation reminds us of the "Holypager" live art piece which used a HackRF to receive and print out live pager messages with an aim to demonstrate the amount of personal data being sent publicly over pagers. Another related art piece was the "Ghosts in the Air Glow" project by Amanda Dawn Christie, which saw the HAARP Auroral research facility used to transmit various art pieces to be received from all over the world by people with HF radios.
[@aang254] made a custom HRPT decoder and ported HRPT blocks for NOAA, METEOR and MetOp to work with gnuradio 3.8 on Linux. Right now it is the only free and open source decoder for MetOp (that works), and he also thinks about implementing FengYun support. I tested the decoder and it works great.
He's also working on extracting the full data from HRPT, not just the AVHRR/MSU-GS imagery but also all the telemetry and other instrument data.
HRPT is a high resolution weather satellite image signal that is broadcast from the same NOAA satellites that provide the more commonly received low resolution APT images at 137 MHz. HRPT is also broadcast by the FengYun-3, Metop and Meteor satellites. However, HRPT transmits at 1.7 GHz, so a high gain dish antenna with motorized tracking mount (or hand guided tracking), LNA and a high bandwidth SDR like an Airspy is required to receive it.
Apart from APT there is also the HIRS instrument data which is transmitted in the Direct Sounding Broadcast (DSB) telemetry signal that is spaced at a slight offset from the APT frequency. According to NOAA, the HIRS instrument is "a discrete stepping, line-scan instrument designed to measure scene radiance in 20 spectral bands to permit the calculation of the vertical temperature profile from the Earth's surface to about 40 km". The SDR# screenshot below shows what the HIRS signal looks like, and to the sides you can see NOAA APT signals.
NOAA-HIRS-decoder makes use of the Project-Dessert-Tortoise NOAA satellite telemetry decoder that we posted about previously which can be used to decode data from most of the other scientific instruments on the NOAA satellites. The HIRS decoder by Zbigniew uses the raw text data produced by the Project-Dessert-Tortoise decoder and converts it into images. Full instructions on setting up the decoder on Windows is provided on the NOAA-HIRS-decoder website, just click the menu icon on the top right of the page, and go to "usage".
The received data contains 10 channels of long wave infrared, 9 channels of medium wave infrared, and one visible light measurement. The software will plot the 20 channels as images that are 56 pixels wide. This is not a high resolution picture, but it is nevertheless valuable data that can be used for scientific or weather prediction purposes.
A new video showing how to build a V-dipole for weather satellite reception has been uploaded over on the Tech Minds YouTube channel. A V-dipole isa dipole antenna arranged in a 120 degrees "vee" shape, and mounted horizontally. It was first popularized by Adam 9A4QV who realized that such a simple antenna would work well for low earth orbit satellites like the NOAA and Meteor weather sats.
The video shows how to use some steel rods, a plastic pipe and terminal block to build the v-dipole. After building and mounting the antenna in the required North-South orientation he shows how he's using Gpredict with SDR# and WxToImg to decode the NOAA satellite image.
How To Build A V Dipole For Receiving Weather Satellites
Over on YouTube the "Unboxing Tomorrow" channel has uploaded a video explaining how he uses RTL-SDR dongles to monitor various radio channels for storm warnings. He notes how he uses his RTL-SDR to monitor the NOAA national weather service channel as well as the Skywarn channel which is the amateur radio based storm spotting network used in some parts of the USA. He also monitors a P25 trunking network with DSD+ for good measure.
In addition he shows a bit of his setup which includes an RTL-SDR Blog V3 and Raspberry Pi connected to an LCD screen all mounted on a neat rail system made from T-slots.
In addition, he's also noted how the default config files provided by goestools do not download EMWIN (Emergency Managers Weather Information Network) images. EMWIN images are not photos, but rather weather forecast and data visualizations that may be useful for people needing to predict or respond to weather. Over on his Github he's uploaded a modified version of goestools which has config files for EMWIN and other image products that might be of interest to some.
If you're interested, Carl Reinemann also has various bits of information about building APT/Meteor satellite RTL-SDR receivers on his main site too. Of interest in particular is his notes on creating wide area composites of NOAA APT images with WXtoIMG which we have posted about in the past.
Over on YouTube the "Ham Radio Crash Course" channel has uploaded a new video showing how to receive APT images from NOAA weather satellites. There are many tutorials (such as ours here) and videos on this topic already, but more cannot hurt, and this one makes specific reference to how to download the WXtoIMG software now that the official website has been abandoned.
In the tutorial he uses an SDRplay with SDRuno as the receiver software, VBCable as the audio piping software, and WXtoIMG as the decoding software.
How To Receive Images Directly From NOAA Satellites
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.