Current topics on Radio Astronomy and looking for advice

Question

Background and Question: I'm an undergraduate student interested on Radio Astronomy. I consider myself enthusiastic about it and I project myself following this "path" so I'd like, apologizing myself if this is a naive question, to ask you, more experienced astronomers, what are the current topics being part of research in Radio Astronomy.

My thoughts:

• I know Cosmology and CMB Measurements are something that will keep its route for a long time as huge projects continue being developed.
• Also I'd say Radio-loud Galaxies are something that Radio Astronomers are putting lots of work into.
• Interferometric techniques, data reduction algorithms and image synthesis.
• Astro-Chemistry and the study of spectral lines using data cubes such as provided by ALMA.

More questions:

• Am I wrong with any of the topics listed? What else is being done now?
• How do you see this in the next 5 - 10 - 20 years ?
• Considering I want to work on my thesis project this year, what would you recommend (or to other undergrad. students) ? What would be a "good route" to follow after graduating? (my grades to this date are at ~ 80%).

Answer 1

Here are some examples that you can read about within Astronomy SE and Space SE:

Time Domain Astronomy (link)

e.g. LOFAR and (as it turns out) CHIME. Think better FRB detection gravitational lensing effects on pulsar timing (needs several questions of its own)

• Why did it take five years to "figure out" how to use astrometric calibration sources to deblur LOFAR images?
• Open dataset from antenna array

and

• How tightly clustered are the CHIME-detected FRB repeats?
• What are the challenges for the building and data analysis of the CHIME telescope?
• How does Canada's radiotelescope CHIME manage polarization-dependent apodization of the fast f/0.25 optics?
• What will succeed the Arecibo Observatory?

also

• What exactly is interplanetary scintillation; what was the Interplanetary Scintillation Array looking for? Did it successfully observe any?

Space based, and Satellite VLBI

• Far Side of the Moon stuff, e.g. Chang'e 4: The NCLE on the orbiter and the LFS on the lander work in synergy performing low-frequency (0.1–80 MHz) radio astronomical observations.
• What can be learned from low frequency radio astronomy available outside of Earth's ionosphere?
• Has VLBI been done using any space-based receivers besides Spektr-R? (Space SE)
• What's the status and timeline for Millimetron? (Russia's 10m Deployable Antenna cooled to 6 K Earth-Space VLBI) (Space SE)
• What are Spectr-R's major contributions to radio astronomy that could not have been done from Earth? (Space SE)
• How is Spektr-R doing these days? (Space SE)
• Has VLBI been done using any space-based receivers besides Spektr-R? (Space SE)
• What kind of ground-based radio astronomy is NASA's DSN used for? Who are the PIs? (Space SE)
• Are images of exoplanets' surfaces technically possible? (Space SE)
• Could a radio telescope orbit Earth-Moon L2 so that it is in the Moon's radio shadow?
• Rotating liquid mirror on the Moon: this answer to Why can't we build a huge stationary optical telescope inside a depression similar to the FAST?

Fancy, complicated focal plane arrays and techniques

• How would a Fast Fourier Transform Telescope work without a mirror, dish or lenses?
• How do ASKAP's focal plane phased array feeds interact with the entire array phasing?
• What is the highest granularity focal-plane array on a dish radio telescope? Or is this the ONLY ONE?
• Would Adaptive Optics be Useful in Radio Astronomy?
• Has radio astronomy ever been done on objects that appear very close to the Moon? Is this avoided?

Radar Astronomy (link)

• What are recent discoveries with Earth-based radar telescopes?
• What will succeed the Arecibo Observatory?
• What causes "North-South ambiguity" when doppler radar imaging a planet surface equator on?
• https://space.stackexchange.com/q/22493/12102
• What is the physical geometry of this apparent "eclipse" of a tiny moon of Asteroid Florence?
• Farthest distance to a solar system object that's been measured by radar? (Space SE)
• How did Arecibo detect methane lakes on Titan, and image Saturn's rings? (Space SE)
• Why is Saturn invisible in this radar image of its rings? (Space SE)
• Why was the 100m Green Bank dish needed together with DSN's 70m Goldstone dish to detect Chandrayaan-1 in lunar orbit? (Space SE, not exactly Astronomy but pretty cool from an instrumentation and signals point of view)
• Why are Titan's lakes “black” in radar images rather than transparent? (Space SE)
• Is delay-doppler radar imaging of NEO asteroids possible only if it spins fast enough? (Space SE)
• Separating fact from fiction, how to get from this radar image to this GIF? (Space SE)