April 16th 2020 bolide in Peru

Around 2020-04-16T01:02:10 UTC a bolide was sighted in Peru. The good news is that the SIMONe Peru meteor radar network at the Jicamarca Radio Observatory was operational. The team at IAP Kühlungsborn are trying to figure out the trajectory for this bolide.

So far, we have been able to detect trail echoes corresponding this bolide in the data for three receiver stations and an approximate location for the atmospheric entry point for the bolide has been determined from the trail echo.

I have been helping out with the IAP effort by writing some new analysis software, which allows head echoes to be detected in the coded continuous-wave meteor radar data. I ran the data for one of the transmit-receive links (Jicamarca Radio Observatory -> Azpitia), and was able to detect the range and Doppler shift of the bolide! I'm now working on the other links. You can find my code here: https://github.com/jvierine/meteor_head_cwradar/

Let's hope we can piece together a trajectory and hopefully then we can recover some meteoric rocks!

Here are some videos I found on social media. One can definitely see the meteor fragment towards the end of some videos. I unfortunately was not able to determine who shot these videos, so I can't give proper credit.

Here is a determination of the position of the trail echo of the bolide, which was made by Carsten Schult at IAP.

The locations of the radar receivers are shown in blue. The transmitter is shown in red. (Figure: Carsten Schult)

Here are some measurements of the trail echo at Huancayo and Azpitia made by Miguel Urco. The transmitter in Jicamarca is a MIMO transmitter, with five spaced antennas, each transmitting a different pseudorandom code. This allows us to localize the echo in space using phase and time delay, just using one receiver. This is somewhat similar to how GPS works, except that in this case, we have five radar transmitters located Jicamarca Radio Observatory, instead of GPS satellites flying in space.

Range-Time-Intensity plot of echo power measured at Huancayo. The range corresponds to total range between Jicamarca and Huancayo. The echo lasts for about one minute! (Figure: Miguel Urco)

Here are phase differences measured between transmit antennas. This is in the case of the Jicamarca-Azpitia path. The uniform phase means that the echo is coming from a certain direction, and the phase difference is determined by the locations of the transmit antennas and the location of the meteor trail. (Figure: Miguel Urco)

Here is a range-time-intensity radar measurement of the same bolide, showing a head and trail echo. With the head echo, it may be possible to determine an accurate trajectory, assuming that we can get
a similar head echo from at least three links.

Range-time-intensity of radar echoes corresponding to the April 16th bolide. The head echo is the weak echo, which is traveling down in range. The trail echo is the strong echo that follows the head echo, which is caused by the turbulent plasma wake left behind the meteor as it burns up in the atmosphere.
Here is an example of the range-Doppler spectrum with a head echo and a trail echo:
Range-Doppler spectrum estimate containing a head echo (left) and a trail echo (right).  This is for the Jicamarca-Azpitia link.

Detected range and Doppler shift. This corresponds to total radio propagation distance (km) and Doppler shift (Hz) for the transmit-receive path between Jicamarca Radio Observatory and Azpitia.