Category: Applications

A Technical Overview of the Watch Duty Wildfire Monitoring Project Powered by RTL-SDRs

Previously in 2022 we posted about Watch Duty, a nonprofit organization aiming to improve access to live public safety information regarding wildfires in California. Several populated regions of California are extremely prone to wildfires, and it's important that residents get timely notifications about nearby wildfires so they can evacuate early and/or prepare their defensible spaces.

The system works by using RTL-SDRs to monitor public safety radio channels, and ADS-B aircraft positions of firefighting aircraft in order to gather information in real time about how wildfires are moving. Volunteers monitor this information and distribute anything of importance via a smart phone app to the public. Often the information is significantly more timely compared to official channels.

Recently Nick Russel, the VP of Operations at Watch Duty sent us a link to a technical overview blog post explaining how their 'Echo' remote monitoring devices work. The post describes how Echo devices consist of a Raspberry Pi and multiple RTL-SDR Blog dongles, with all the electronics being powered via Power over Ethernet (PoE). For the antenna a wideband Discone is used. 

Inside the Watch Duty 'Echo'
Inside the Watch Duty 'Echo'

The rest of the post explains how their voice monitoring system works, how "tone out detection" works, which are orders for engines, strike teams, and other heavy equipment, how they make use of ADS-B data and how they are able to remotely maintain and update the system.

Importantly, Watch Duty note that they rely on volunteers and donations from the community, so please consider donating via the Watch Duty app.

Watch Duty | Echo Radio Project | Fixing emergency radio dead zones

Lab401: HackRF on Windows YouTube Tutorials

Over on the Lab401 YouTube channel, 'RocketGod' has uploaded three videos that are various tutorials for the HackRF on Windows. The first video covers the basics like installing software and shows how to decode pager signals with PDW.

The second video shows how to decode police transmissions, car key fobs, use rtl_433, and how to use Universal Radio Hacker to capture and analyze signals. 

The third video is not yet released, but is due to premier on YouTube in 10 hours from the time of this post. In that video RocketGod will show how to install and use DragonOS, and how to install and use SDR Trunk which turns the HackRF into a police scanner. Finally, he will demonstrate SDR Angel and show it decoding ADS-B signals from aircraft to show you live flight tracking data.

Part 1 is embedded below, and Part 2 and Part 3 are linked here.

ROCKETGOD's HackRF One guide - part 1/3 Basics, Windows apps, setting up - LAB401

SDRSharp Controller Plugin: Control SDRSharp via any USB Hardware Controller

Thank you to Alan De Windt who has submitted news about the release of his latest SDR# Plugin called "SDRSharp Controller". Alan writes that this is a plugin that is "similar to the existing SDRSharp Net Remote plugin by Al Brown but which allows simpler physical controllers to be built". 

With this plugin you can create a key/value text mapping to turn any USB control device into something that can control various settings in SDR#. The controller hardware could perhaps be anything from a USB knob controller to a gamepad.

Alan also provides an example of a hardware USB knob controller that he's created which works together with the plugin. On the linked page he shows the components required to build the controller, how to wire up the circuit and provides the Arduino code.

A custom SDR# controller knob

Saveitforparts: Building an L-Band Satellite Antenna out of an Umbrella

Over on his YouTube channel "saveitforparts" has uploaded a video where he uses an umbrella, pin tin and tin foil tape to create a simple dish antenna for receiving GOES, NOAA and METEOR HRPT satellites.

The full build consists of an umbrella covered in tin foil tape, a helical wire feed on a pie tin, a filtered LNA, an RTL-SDR and an Android phone running SDR++. While he did have initial success at receiving, he soon decided to swap out the helical wire feed for a PCB linear feed instead which worked much better as helical feeds can be very difficult to get right.

Through the video saveitforparts goes over the failures he had, in the end noting that it's not a great antenna, but it's something that can be used in a pinch.

We've also seen the umbrella satellite dish used a few times in the past, where here it was used for NOAA APT reception, and here for Hydrogen Line radio astronomy.

We also want to remind readers that we are currently Crowd Funding for our Discovery Dish, which will be a low cost way to get into L-band satellite reception.

Can I Get Satellite Data With An Umbrella?

DragonOS: Tracking ADS-B, UAT, ACARS, VDL2 with TAR1090 and a KrakenSDR

Aaron who created and maintains the DragonOS SDR Linux distribution has recently uploaded a new video where he uses a KrakenSDR to simultaneously receive and decode multiple aircraft tracking, telemetry/messaging signals including ADS-B, UAT, ACARS and VDL2.

In the video Aaron uses his WarDragon which is a Mini PC that comes preinstalled with DragonOS. It is currently available on his website for $220, or $550 including a carry case, and Airspy R2.

The video shows how to setup all the software including FlightView GUI which is a graphical user interface that allows users to manage and configure various Docker based aircraft-related services including tar1090, readsb and acarshub.

WarDragon ADS-B, UAT, ACARS, and VDL2 w/ TAR1090 + ACARS Hub (KrakenSDR, Defli optional)

DragonOS: Running GNSS-SDR and Obtaining a GPS Position with an RTL-SDR and Patch Antenna

Over on his YouTube channel Aaron who created and maintains the DragonOS SDR Linux distribution, has uploaded a video demonstrating how to use the GNSS-SDR software together with an RTL-SDR and patch antenna to obtain a live GPS position.

Previously we had only seen a Windows method involving GNSS-SDRLIB and RTKNAVI working as GNSS-SDR on Linux seemed impossible to get running. However, Aaron managed to find a working RTL-SDR configuration for GNSS-SDR which made it come alive. This is great as now GNSS-SDR should be able to run on a portable single board computer like a Raspberry Pi.

The video is a tutorial that shows how to install all the required dependencies, how to compile GNSS-SDR, how to configure it for an RTL-SDR, and how to use it with our RTL-SDR Blog L-band patch antenna.

DragonOS FocalX Setup GNSS-SDR and Obtain GPS Position w/ RTLSDR (Patch Antenna, WarDragon)

SDRx.IO – A Public Server Network for RTL_TCP and/or Spyserver Stations

Thank you to Matt from SDRx.io for submitting a story on our forums about his project called SDRx.IO which is a service that hopes to be a platform that allows remote users to find and connect to public RTL_TCP and/or SpyServer servers. Matt writes:

A few days ago I started a project called SDRx.io. I could not find any platform with public RTL-TCP servers, so I thought I would try to make one for fun.

SpyServer mode (through internet proxy) is also supported. The official map/directory currently does not seem to support this. SpyServer is the default mode, because SDR stations can "somewhat" be shared between multiple clients.

Users can switch radio station modes using the web interface.

SDRx.io routes traffic in a way that protects the actual endpoint from internet exposure, and the server network acts as a CDN (the project currently has 5 servers). Servers can be seen as proxies for radio stations that host the SDR hardware.

The early preview currently on the site only has my own first 2 stations in Switzerland for VHF/UHF, and I am now looking for other users who would be interested in hosting/sharing new radio stations to connect to this project, or participate otherwise.

Required network throughput for RTL-TCP is about 35 mbps at 2.048 MS/s

I know there are already several other projects with public SDR servers, but few carry the full IQ signal, and none are currently providing direct TCP connections compatible with the rtl_tcp protocol.

Your feedback is of course welcome here :D

The service is currently not yet active due a lack of initial interest, but if you are interested you can get in contact with Matt at [email protected].

SDRx.IO Homepage

Automating NOAA APT and Meteor M2 LRPT Reception with SatDump 1.1.2

SatDump is a popular program used to receive and decode various forms of weather satellites, and in recent updates they added support for NOAA APT and Meteor M2 LRPT weather satellite decoding. In the latest 1.1.2 release they have also now added support for automation, amongst many other improvements.

Before this update, to automate the reception and decoding of APT and LRPT satellites a Windows PC, and a huge stack of various decoding and tracking programs and SDR# plugins are required, some of which are now even abandonware.

For APT a typical chain was SDR# -> DDETracker -> Orbitron -> WXtoIMG and for LRPT a typical chain is SDR# -> DDETracker -> Orbitron -> LRPT Demodulator -> LRPT Decoder -> SmoothMeteor -> MeteorGIS. Setting this chain of programs up can obviously be a lot of hard work.

The latest version of SatDump adds automation features which means these two entire chains can be replaced with just one program - SatDump. SatDump is available for Windows, Linux and Mac, so it can even run on something like a Raspberry Pi 5 or Orange Pi 5. 

To help users set up automation, @original_lego11 has written up an excellent tutorial that shows how to set the automation up. Automation involves entering your ground station details and selecting and configuring what satellites you want to receive and decode with your RTL-SDR or other SDR hardware.

SatDump 1.1.2 with the new automation features