Tagged: weather satellites

Discovery Dish Updates and Some Cool Hi-Res Images

We have recently posted an update on our Discovery Dish crowd funding campaign over on Crowd Supply. Check it out on the update page, or on the repost down below.

Discovery Dish Teardown Session Livestream Recording

Thank you to Helen Leigh and Crowd Supply for featuring us on one of their Teardown Sessions live streams a few days ago. If you missed it, feel free to watch the recording below. On the livestream we discussed the Discovery Dish and talked a bit about the journey we took to get to the final product design.

Teardown Session 38: Discovery Dish

Enclosure Glands and Vents

We have decided to include a few cable glands and vents with the Discovery Dish Enclosure, as these will ensure that the bottom of the enclosure is protected against water jets and any splash back from the ground, as well as allowing the electronics inside to breathe a bit. Allowing waterproof enclosures to breathe is important in many environments to avoid condensation build up inside.

The glands and vents will be metal to ensure that RF tightness of the enclosure is maintained as much as possible.

The electronics inside can be passively cooled via thermal pads that sink all generated heat to the metal enclosure which acts as a large thermal mass and heatsink.

In the image below you can also see the mounting board. We are still planning to reduce the hole spacings on the board.

Rotator Timelapse

We’ve been testing an early prototype design of our upcoming antenna rotator for the Discovery Dish, and have created a quick preview timelapse of it running overnight. With mechanical designs like this it’s important to do some long-term testing, so we’re going to be running prototypes non-stop for several months while tracking many more satellites than would be typical.

DD Rotator Preview

 

Example Weather Satellite Images Downloaded

Some people have asked for high resolution examples of what can be received from satellites with the Discovery Dish. Below are a few samples.

GOES 18 Full Disk

Discovery Dish GOES 18 Full Disk Blend

 

GOES 18 Mesoscale

GOES 18 EMWINN

GOES 18 NWS

Metop AVHRR (Advanced Very High Resolution Radiometer)

Metop IASI (Infrared Atmospheric Sounding Interferometer)

GK-2A Full Disk

FengYun 4A Full Disk

Meteor MSU-MR (Multispectral Scanner Unit - Medium Resolution)

NOAA AVHRR (Advanced Very High Resolution Radiometer)

Crowdfunding Goals

We just wanted to clarify a point regarding how crowdfunding works. If the goal isn’t reached then everyone who ordered won’t be charged. We have had a few concerns from potential customers wondering if we will keep the money if the goal isn’t reached, but this is certainly not the case! In fact, credit cards will only be charged if we hit our funding goal. You can learn more in the Crowd Supply Guide.

The goal is set relatively high as this product requires a number of molds to be created for the dish and the various plastic parts, and molds typically have a high fixed initial cost. There is also a high minimum order quantity that we need to commit to in order to do a production run.

But the campaign is currently over 70% to its funding goal and we are expecting some large reseller orders to come in during the last few days of the campaign, so please don’t worry as the goal will almost certainly be reached with the help of just a few more individual supporters. If you have been on the edge, please consider supporting us to get this product started!

Customer Questions

In my environment temperatures get down to -20 to -30 degrees C. Will the electronics in the feed hold up?

The components used in the feed all have ratings down to at least -40 degrees C. In very cold environments, the one thing we would suggest considering is if a dish heater is required. These are heating strips that can be placed on the dish and can help melt snow/ice buildup.

What is the hole pattern on the dish?

The hole pattern on the dish has no specific function, the holes are simply used for reducing wind loading and weight. The manufacture of the prototype dish requires that the holes be cut by laser cutter, but the laser cutter we have available was not large enough to do the entire dish at once. So it was manually rotated around, and this caused an uneven pattern.

The production version of the dish will split into three petals, and each petal will be manufactured via a stamping process. Stamping is when a sheet of metal is placed under a heavy molded block of metal, and then that block of metal is pressed down on the sheet metal to create a desired shape. With this stamping process we will have perfectly neat hole patterns.

I suggest that the S-band version of the feed not use a downconverter, and just use an SDR that can receive S-band instead.

We currently have a similar opinion.

To explain this customer question/comment, we note that as mentioned in the previous update, we are planning to soon test an S-band version of the feed which should be able to receive S-band satellites.

However, the typical software defined radio used is an RTL-SDR, which cannot reach S-band frequencies like 2.2 GHz where most S-band satellites transmit. To get around this, we could add downconversion circuitry to the S-band feed, which would increase complexity and cost. This would convert the 2.2 GHz frequencies down to a frequency that the RTL-SDR can receive (below 1.766 GHz). Alternatively, we could simply recommend that customers interested in S-band reception instead use another SDR such as the HackRF, PlutoSDR, or LimeSDR Mini 2.0.

Once we have tested the S-band version of the feed, we will make a decision on if we should add a downconverter or just recommend the use of other SDRs that can reach the S-band.

Can any of the feeds be used for 1296 MHz EME (earth-moon-earth bounce communications)?

Sorry no, the feeds will not be suitable for EME, as that requires transmission which our feeds do not support.

I would like to use the dish on an astronomical mount. What is the expected weight of the dish and feed?

The dish itself weighs less than 1 kg (2.2 lbs). Together with the feed and mount we expect it to weigh a total of less than 1.5 kg. This is significantly lighter than a Wi-Fi dish which is already 1.6 - 2 kg (depending on the brand) for just the dish by itself.

Are weather satellites encrypted?

No, most weather satellites like this are not encrypted. Although these satellites come from various countries’ governmental space and/or military agencies, weather satellite data is generally considered public science. If it’s not necessary, adding encryption is undesired as it adds complexity to the system and increases the amount of data that needs to be transferred.

Obviously high-end military and commercial satellites are encrypted and we cannot receive data from those. It’s possible that future weather satellites could be encrypted, but given the current trend of new weather satellites being unencrypted this seems unlikely.

 

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.

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

Raspberry-NOAA V2: Raspberry Pi Automated NOAA and Meteor Weather Satellite Capture

Raspberry-NOAA is open source code and a set of scripts that allows you to set up a Raspberry Pi as an automated NOAA and Meteor weather satellite station with an SDR like an RTL-SDR. The software makes use of the Raspberry Pi version of WXtoIMG and meteor_decoder for decoding the satellites, a program called predict for predicting satellite passes, and various automatically generated cron scripts to schedule recording and processing.

Recently V2 has been released by Justin Karimi who builds on the work of the original creators. It seems that the webpanel has been upgraded and made mobile friendly, as well as many more enhancements that can be seen on the Release page notes.

Raspberry-NOAA V2 Web Panel

Look4Sat: An Android App for Tracking and Predicting Amateur Radio and Weather Satellite Passes

Thank you to Arty Bishop for submitting news about his recently released Android App called Look4Sat. Look4Sat is a satellite tracker and pass predictor with a focus on amateur radio and weather satellites. The app is free, ad free, and open source on GitHub.  Arty writes that he's programmed this as a learning exercise and notes:

I always wanted to have an offline and not bloated satellite tracker on my phone, as carrying the laptop at all times is kinda not too handy.

The app uses predict4java library under the hood and is written in Kotlin. The TLE files are from Celestrak and the transmitters info is from SatNOGS and once they are  ownloaded the app doesn't need an internet connection.

The app creation and design is hugely inspired by Gpredict which is an absolutely brilliant piece of software. Thank you, Alexandru!

Obviously there is no ads and it's totally free. Hope more people find Look4Sat useful.

The features include:

  • Calculating satellite passes for up to one week (168 hours)
  • Calculating passes for the current or manually entered location
  • Showing the list of currently active and upcoming satellite passes
  • Showing the active pass progress, polar trajectory and transceivers info
  • Showing the satellite positional data, footprint and ground track on a map
  • Offline first: pass prediction is done offline. It's up to you to decide when
    to update the TLE file and the transceivers DB. (Updates once a week are recommended)
Look4Sat Android App Screenshots
Look4Sat Android App Screenshots

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.

Track Satellites in Orbit - 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.

Tracking Satellites in Orbit - Part 1

YouTube Videos: NOAA Satellite Tutorial and Building a Radio Telescope

Over on the Thought Emporium YouTube channel the team have uploaded two videos that may be of interest to radio hobbyists. The first video shows a nice overview about receiving NOAA weather satellite images. They explain everything from scratch for complete novice, so the videos are great for almost anyone to watch and learn about radio and SDR concepts. The blurb of the first video reads:

Over the past 2 months, me and my friend Artem have been building antennas to receive signals from weather satellites as they pass overhead. This video chronicles our progress through this project and goes through some of the science involved in working with radio and receiving transmissions. We explore how dipoles work and how to build them, and how we built our final double cross antenna. We used an SDR (software defined radio) called a HackRF to do the work of interpreting the received signals and then decoded them with some special software. We pulled images from 4 satellites: NOAA 15, 18 and 19 as well as METEOR M2. The satellites broadcast immediately as they take the images and no images are stored, so we’re likely the only ones on earth with these images.

How to Pull Images from Satellites in Orbit (NOAA 15,18,19 and METEOR M2)

The second video is about building a radio telescope. Like the NOAA video, they explain all concepts in a simple and easy to understand way, so that anyone even without any radio knowledge can understand what the project is about. In the video they also show how they use a 3D printer to create a tracking mount which can point a satellite dish. They then use the dish to create a satellite heat map. The blurb reads:

Over the last 2 months me and my friend Artem (you met him in the last video) built our first radio telescope. It was built mostly out of off the shelf components, like a satellite dish and Ku band LNB, as well as some parts we 3d printed. When all was said and done we had a system that could not only take images of the sky in radio frequencies (in this case 10-12ghz), but could also be used to track satellites. With it, we were able to see the ring of satellites in geosynchronous orbit, over 35,000km away, This is only the first of what I suspect will be many more telescopes like this. Next time we’ll be building ones that are far larger and can see things like the hydrogen lines so we can image the milky way.

How to Build a Radio Telescope (See Satellites 35,000km Away!)