Wow, why is a Russian satellite signal stronger than all the GPS satellites in New Zealand?

Something bright in the radio sky

First noticed yesterday (24 Feb 2019) that a very bright object has appeared in the radio-sky at civilian GPS frequency (1.575 GHz).. This object is stationary, and it's sky-coordinates corresponds to the Russian LUCH 5A geostationary satellite. It hasn't moved in more than 24 hours.

This object is so bright that all other GPS, Galileo and even the Japanese QZS satellites are drowned out. The image below is a snapshot all-sky image taken with the TART radio-telescope located in New Zealand. 
An all-sky radio telescope image showing the Russian military satellite
Transient Array Radio Telescope all-sky image taken from near Dunedin New Zealand. Image Date: 2019-02-25 10:57am NZDT. The image is looking straight up, with the largest circle being the horizon. Due south from New Zealand is down.

What is it the Luch 5A?

The position corresponds to a Russian geostationary relay satellite, the LUCH 5A. My estimate is that the signal strength is 300 times stronger than a GPS satellite signal. This satellite has two antennas in the S- and Ku-band antennas for communications between spacecraft in the low Earth orbit, including ISS, with mission control when they are beyond the range of ground control. 
The Luch 5A satellite. Image (c) Bin im Garten [CC BY-SA 3.0]
The satellite , shown above, has two large directional antennas, which might be capable of operating on the GPS L1 band. However the L1 band does not lie in the 2-4 GHz range of the S-band or the 12-18 GHz Ku band. 

 Certainly the signal strengths observed are consistent with a large directional antenna pointing at New Zealand.

What is it doing?

Really, I have no idea, but would love to know. Aside from drowning out all other sources in our radio telescope, there is a small chance that the strong signal will reduce the effectiveness of civilian GPS receivers that operate in the L1 band at 1.575 GHz.

How is the Telescope Image

The radio-telescope that detected this interference consists of 24 antennas operating together to create an image of the entire sky. The telescope is  an open-source project developed by  Elec Research in New Zealand. More information about the telescope is available here.

Comments

Post a Comment

Popular posts from this blog

Installing Tensorflow and CUDA 10 on Debian Buster the easy way

Installing Tensorflow and CUDA 10 on Debian Buster the easy way There is plenty of conflicting advice on installing GPU accceleration (CUDA) on Debian machines.  If you haven't yet purchased a GPU, I'd recommend getting an AMD GPU and installing ROCm. It just works, and the driver is built into the linux kernel! If however you have an old Nvidia GPU (I have a 1070Ti) there is a pretty easy approach is outlined here ... This link needs to be updated to use the latest tensorflow which depends on CUDA 10. Step 1. Install Nvidia Drivers This requires a specific version of the nvidia driver (418.56 at the time of writing). This is available in the stretch-backports repository. So first add a line for stretch-backports to /etc/apt/sources.list Then clean out any other version of the driver (really you want to uninstall all possible nvidia software.     aptitude purge nvidia-driver nvidia-dkms nvidia-alternative nvidia-legacy-check nvidia-opencl-common libcuda...
Read more

The three golden rules of SPICE in KiCAD

Image
There are three things that stop spice from working inside KiCAD. Here they are. 1. Use a .spiceinit file To allow ngspice to use PSPICE models, place a .spiceinit file in your home directory. With the contents: * user provided init file set ngbehavior=ps 2. You need a zero node Always place a node zero from the PSPICE library in the Schematic Editor. Normally you will connect this symbol to your ground. 3. Match Package Pins Always match the pins on the package to the SPICE model pins. This is done when you edit the spice model for a component. For transistors, SPICE expects pins 1,2,3 to be collector, base, emitter respectively. You should modify the pin order to match the pins in the pakage. For the BC807 the correct alternate numbering is 3,1,2 as pin 3 is the collector, pin 1 is the base, and pin 2 is the emitter. See Figure below For the 741 model, the pin order must match the package pins.
Read more