1. A method for acquiring a magnetic resonance measurement data set of a breathing subject, comprising: operating a magnetic resonance apparatus, in which a breathing subject is located, to acquire a plurality of magnetic resonance data subsets; entering the plurality of magnetic resonance data subsets into an electronic memory representing k-space, wherein k-space is comprised of a plurality of segments, and entering the respective magnetic resonance data subsets individually into respective k-space segments; also operating said magnetic resonance apparatus to make at least two navigator data acquisitions, before each respective acquisition of said magnetic resonance data acquisitions subset acquisitions, and using said navigator data to determine a respiratory position of the subject, and a respiratory phase of the subject and assigning said respiratory position and phase to the magnetic resonance data subset acquired in the respective acquisition; and providing the respiratory position and the respiratory phase to a processor and, in said processor, using the respiratory position and the respiratory phase, assigned to each of the magnetic resonance data subsets, to decide automatically whether a respective magnetic resonance data subset is included or not included in a final magnetic resonance data set from which a magnetic resonance image is to be reconstructed, and making said final magnetic resonance data set available in electronic form at an output of said processor.