The phrase "are capable of observing" is correct and usable in written English.
You can use it when discussing someone's or something's ability to notice or perceive something.
Example: "The researchers are capable of observing subtle changes in behavior over time."
Alternatives: "have the ability to observe" or "are able to notice".
Today's radio telescopes are capable of observing at most wavelength regions from a few millimetres to about 20 metres.
"Mankind is everywhere the same," she writes to her daughter, then adds: "This observation might be carried yet further: all animals are stimulated by the same passions, and act very near alike, as far as we are capable of observing them".
Recently developed real-time DNA microarrays are capable of observing kinetics of the binding process.
Similarly, the objects of propositional attitudes are fixed by looking to find objects that are the common causes, and so the common objects, of the attitudes of two or more speakers who are capable of observing and responding to one another's behaviour.
Three GCR observations responsible for different rigidities, GG-component (approximately 80 GV), GMDN (approximately 60 GV), and NMs (approximately 17 GV) are capable of observing the NS anisotropy on daily basis, and their cross-calibration allows us to obtain the information about the rigidity dependence of the NS anisotropy.
When the New Horizons team set out to map the mission's trajectory, they discovered that no one knew precisely where Pluto was; its orbit takes so long (two hundred and forty-eight Earth years) that humankind had been capable of observing only about a third of it, and the best guesses as to its distance from the sun had a six-thousand-mile margin of error.
Several detectors exist that will be capable of observing some subset of those neutrinos.
The satellite will be capable of observing exoplanets in a Neptune Earth scale and obtaining data of interstellar dust.
The detector is capable of observing very low neutron fluxes in the presence of ambient gamma background and does not require scintillator pulse-shape discrimination.
Feed the computer enough data on a number of "parallel universes," she wrote, and the computer will be capable of observing the implications of each of these universes and then find patterns, allowing predictions to be made about the future of the conflict.
This facility is capable of observing from 0.3 μm to 1.6 mm with an average transmission greater than 80% averaged over all wavelengths.
