I perform comparison tests of the levels measured between these 2 devices, in particular the maximum level observed in an acoustic image and the level measured by a sound level meter at the same distance from 1 controlled sound source, I look for references in similar experiences, thanks.
With a sound level meter you want to know the sound level in the microphone position. With an array you want to know the source levels in all geometry around your position to detect sources. Then you can say that the sum of all sources has to be comparable with the sound level in the microphone position measured using a sound level meter. Anyway in general the source levels identified using arrays can be valid as a relative source power but not in absolute value.
In support to Tim's comments, I would comment that a single microphone records the global fluctuation of pressure: if your sensor faces a flow (wind, moving support...) then you record also "pseudo sound" which is pressure variations that remain local: sound is solely the fraction of dynamic pressure that propagate unattenuated (in energy terms in a perfect fluid) as being the "singular value" of the equilibrium equation.
You need an array to excerpt in the vicinity of the sound source the true sound from the pseudo-sound, and a well suited processing (e.g. the acoustic holography quoted by Tim)
In a calm fluid, far from the source, an array is only helpful to improve the Signal/Noise ratio as it provides a Directivity Index. The array size must exceed several wavelengthes while the mike's spacing must remain less than half wavelengths (lambda/2) at Freq max (Shannon condition)
I don't understand really what you mean by "acoustic image" but it sounds like acoustic holography. As it filters the pseudo-sound, you should find the same sound level if you "propagate the image" with your holography algorithm up to your point of measure, as long as your mike is at least at lambda/3 of the sound source ! (or more if the source is not punctual re wavelength)
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