Huh² Better Late Than Never... Discuss CURIE will investigate where solar radio waves originate in coronal mass ejections, like this one seen in 304- and 171-angstrom wavelengths by NASA’s Solar Dynamics Observatory. (Credit: NASA/Goddard Space Flight Center) SPACE (KXAN) — Radio signals are coming from somewhere within our sun and NASA wants to find out from where. On July 9, the space administration will launch the first mission designed to locate these signals: CURIE. The CubeSat Radio Interferometry Experiment (CURIE) will use two small cube satellites to locate the source of these radio signals, emitted during solar storms, solar flares and coronal mass ejections (CME). Understanding more about these forms of space weather is extremely important. Storms on the sun can impact technology on Earth, including our communication networks. According to NASA, scientists first detected these radio signals decades ago. While they know that they occur during solar storms, they don’t know where from. Solar storms and flares could soon be detected in advance of communication blackouts According to the European Space Agency, these radio waves must be observed from space. The Earth’s ionosphere absorbs them before they reach the ground. The ionosphere extends 30 to 600 miles above the Earth’s surface and is filled with charged gasses. How will NASA track mystery radio signals? CURIE, once in orbit, will separate into two. The two cube satellites will then move two miles apart. CURIE team members work on integrating the satellites into the CubeSat deployer. (Credit: ExoLaunch) When the sun emits a radio wave, the two satellites will capture the signal and then triangulate where it came from. CURIE will fly into orbit onboard the Ariane 6 rocket. This rocket is operated by the European Space Agency. It will be its first flight. CURIE is sponsored by NASA’s Heliophysics Flight Opportunities for Research and Technology (H-FORT) Program. NASA later plans to launch the SunRISE mission, which will track radio signals with six satellites. SOURCE: https://www.kxan.com/news/science/mysterious-radio-signals-focus-of-new-solar-mission/
To be on the right track, to get to know the mechanism in and of the Sun. Basic research, not only for space weather.
The satellites will receive signals from 100kHz to 19MHz https://www.ssl.berkeley.edu/curie-ready-for-ariane-6-launch/ https://space.skyrocket.de/doc_sdat/curie.htm
AT any given time, this is a 2 element interometer with a fixed baseline. If you ASSUME the area of eruption is not changing over a large frequency range---say 1 MHz to 10 MHz--then you can let the spatial frequency spectrum be deteremined by measurements at different frequencies and actually 'image the region. In that case all you have is a single data point of fringe at each frequency and each frequency must be regarded as independent. IMO that is a poor assumption. The grating lobes are a major PITA and will clearly pick up on other regions of the sun's low freq emission. I would bet the the optical thickness also changes as a function of frequency.IOW the region looks 'different' as you change frequency. Or worse, they will resolve the region and get no fringes. I would see this as a technology demonstrator and nothing else. MO. It DOES bring up an interesting question if, at solar MIN, one of these regions erupts AND hams set up their own earth baed interferometer (you have to observe below the ionosphere's MUF) to 'image ' it. 73 Chip W1YW
Of course the frequencies are low. What the scientist maybe are looking for, can be a magnetic reconnection in or in the near of the Suns core. The connection is the same than the magnetic belt around a nuclear plant. It happens when big electric power is generated.
The sun is opaque. You are incapable of seeing the Sun's core. The core is millions of degrees. The Sun is SO opaque that it takes 1000 years or more for a photon to 'bounce' its way out to space. No one is seeing the core through the blackbody of the Sun.
That's not what's happening here. It is a two element interferometer, where the spatial frequencies are synthesized by using a broad spectrum of RF frequencies. There are only two receiver/antennas. The NRAO description is for multiple antennas and physical baselines.
The on line NRAO demonstration can be configured with two antennas. Are the presented, two antenna, images reasonable? "Physical baseline" as opposed to... ?
The two element interferometer in space can be configured for simultaneous fringing at a variety of frequencies. That means the baseline is wavelengths changes at each simultaneous frequency, thus 'sampling the UV plane' at a variety of points, while the physical baseline is fixed, with one separation length. Most interferometry is done the other way, where there are a variety of physical baselines and many antennas. That two-element approach only works if the object being viewed has the same structure at the simultaneous frequencies. If not, you are looking at different depths of the structure, depending in the frequency.
It is difficult to comprehend that two CubeSats just a couple of miles apart will be able to pin point the source within such a huge object as the Sun, located 150 million km away. Anyway, the space scientists will have their on calculations, unlike my rough guess! Anyway, I liked the name CURIE, which made me remember the works of Madam Curie and Pierre Curie which I read as a high schooler, decades back. If I remember correct, in those days, Madam Curie was the only person who had won the Nobel Prize twice, with the first along with Pierre Curie who passed away much earlier.
W1YW's comments tell us why this is an initial prototype "proof of concept" test. Given budget constraints and the "unknown unknows" that will crop up when gathering data, a "2 element interferometer" demo seems to be a good first step. Note that the final sentence in the "news release" says "NASA later plans to launch the SunRISE mission, which will track radio signals with six satellites." Yup, the experiment's designers aren't dumb. They know that they will eventually need more than two satellites to get detailed info. Kudos to W1YW for telling us why.