Profile cover photo
Profile photo
Juha Vierinen
112 followers
112 followers
About
Posts

Post has attachment
Dr McKay, I presume?
Last Friday marked the PhD defense of Dr Derek McKay's thesis titled: "KAIRA -- The Kilpisjärvi Atmospheric Imaging Receiver Array, Design, operations, and first scientific results". The defense was successful, and our friend shall from now on addressed usi...
Dr McKay, I presume?
Dr McKay, I presume?
radio-science.net
Add a comment...

Post has attachment
EISCAT Svalbard Radar measures NorSat-1
Yesterday, I told you that the latest beam park measurement of space debris detected two clusters of Cubesats. Norway's first satellite, Norsat-1, is such a Cubesat, and after talking with Lasse Clausen from UiO today, I figured out that Norsat-1 is one of ...
Add a comment...

Post has attachment
Correlating space object detections
Beam park radar observations are commonly used to determine how much space debris is out there. One points the radar in one direction, and measures for 24 hours. Each space object observation is recorded, and thus one obtains a statistical sample of the deb...
Add a comment...

Post has attachment
Clustering space debris detections
After we have the output of the range-velocity-acceleration matched filter bank, we still don't have a list of space debris detections. We need to use some machine learning algorithms to cluster out results. I tried K-means and some other techniques, but en...
Add a comment...

Post has attachment
Analyzing Space Debris With the Svalbard Radar
Range-Velocity-Acceleration matched filterbank output for the Svalbard Radar. The colors scale ranges from SNR=12 to 200. The x-axis is range (300 to 3000 km), and the y-axis is time (0 to 200 seconds). The coherent integration length is  ten 1.92 ms transm...
Add a comment...

Post has attachment
ESA and EISCAT 3D Space Debris Simulation Hackathon
Field of view of EISCAT 3D (green lines). Points depict space debris object in space, based on the MASTER 2009 model. Orange points depict space debris objects that can possibly be observed with EISCAT 3D. Last week, Daniel Kastinen from Institute for Space...
Add a comment...

Post has attachment
Observing the universe right after the cosmic microwave background
One of the most exciting radio science discoveries this year is the first detection of the epoch of reionization (EoR) signature. The measurement allows scientists to study the evolution of the early universe right after the big band, by observing HI emissi...
Add a comment...

Post has attachment
Day time D- and E-region at Arecibo
The normal day-time D-region electron density is extremely difficult to measure with incoherent scatter radar. This is because the radar cross-section is very low, about -125 dBsm. Keep in mind, that the radar cross-section of a 1 square meter plate is 0 dB...
Add a comment...

Post has attachment
Arecibo line feed (or what is left of it)
One of the first things I did when I got to Arecibo, was to pay my respects to the line feed that was hacked down by hurricane Maria. This was my favorite feed -- the most sensitive one to use for incoherent scatter radar. Here are some pictures of one of t...
Add a comment...

Post has attachment
Arecibo Ionosonde
Once of the things found in the storage area behind the Arecibo Observatory  is the ionosonde antenna. It's not there for storage, but located there, presumably so that it is further away from radio astronomy instrumentation, causing less interference. This...
Arecibo Ionosonde
Arecibo Ionosonde
radio-science.net
Add a comment...
Wait while more posts are being loaded