Tagged: RSP1

Testing VOR Navigation in the Stratosphere with an SDRplay RSP1 and High Altitude Balloon

Over on the SDRplay blog Jon has posted about the STRATONAV experiment which makes use of the SDRplay RSP1 software defined radio. The STRATONAV experiment uses high altitude balloons to carry the RSP1 as well and a commercial portable receiver. The two receivers were configured to receive aircraft VOR navigation signals in order to test the effectiveness of VOR when used at extreme altitudes of up to 28 km. The VOR navigational data was then compared against GPS tracks, resulting in a measure of how well VOR worked at those altitudes. 

VOR (aka VHF Omnidirectional Range) is a navigational beacon that is transmitted between 108 MHz and 117.95 MHz from a site usually at an airport. In the past we have posted about VOR a few times as it can also be decoded with an RTL-SDR, or used for passive doppler aircraft radar. 

The results showed that VOR navigation does indeed continue to function at extreme altitudes, proving that it can be used as a back up navigation system for stratospheric platforms. They also note that VOR navigation could also be used as a primary navigation system on smaller stratospheric platforms due to its low cost and low complexity to implement.

The full academic paper is available on sciencedirect, or for free via Sci-Hub.

SDRplay RSP1 (seen bottom right behind the metal mount) Flying on a High Altitude Balloon

TV Scrambling With GNU Radio and a FL2K Adapter

[mrgriscomredux] over on [Reddit] was interested in re-creating the nostalgia that was scrambled analog television from the 90s. To do this he captured an NTSC analog video signal using an RSP1 SDR and demodulated that into composite video using GNU Radio to process everything.

The methods that were originally used to scramble analog television are not well documented, however [mrgriscomredux] has done a fine job re-creating it himself in his own way.

He then uses a Python script to modify the “Gated Sync Suppression” within GNU Radio and then transmits that back on to the air using a low cost FL2K VGA adapter we’ve featured on the blog in the past.

These FL2K VGA adapters can be abused as crude software-defined transmitters and we’ve seen people do everything from video transmission to GPS spoofing with them. [Check out the FL2K article here]

broadcasting my own scrambled tv channel with SDR

RSP1 Metal Enclosure Price Reduced to $29.95

Recently we’ve reduced the price of our RSP1 Metal Enclosure upgrade kit from $39.95 down to $29.95 USD. You can purchase the kit from our store. The kit comes with:

  • 1x Metal Enclosure
  • 1x Carry case
  • 1x BCFM Filter with SMA Male to Male Adapter
  • 1x Accessory set including rubber feet, screws, grounding post.

On Amazon USA there are less than 16 units left, and shipped from China from our store there is less than 85. We won’t be restocking this item for a few months so please get in quick if you are interested.

We brought out this kit back in March and instructions for using the kit can be found on this post.

The RSP1 metal case kit
The RSP1 metal case kit

Listening to July’s Arecibo Observatory Ionospheric Heating Campaign

During July 24-31 the large Arecibo Radio Observatory in Puerto Rico (the big dish antenna that you may be familiar with from the movie ‘Contact’) ran an Ionospheric heating experiment which involves transmitting 600kW of net power up into the Ionosphere. This type of experiment is used for researching plasma turbulence in the ionosphere and upper atmosphere.

“The new Arecibo ionosphere HF heater nominally transmits 600 kW net power and has a unique Cassegrain dual-array antenna design that increases gain of three crossed dipoles for each band, using the signature 1000-foot spherical dish reflector,” explained Chris Fallen, KL3WX, a researcher at the University of Alaska-Fairbanks HAARP facility. He has reported that Arecibo would use 5.125 or 8.175 MHz, depending upon ionospheric conditions, but emphasized that these are estimates and frequencies may be adjusted slightly. On July 25, Arecibo was transmitting on 5.095 MHz.

Over on YouTube Mike L. used his SDRplay RSP1 together with our BCAM HPF to record some transmissions from the observatory.

Arecibo on 5.125 am