A new L‐band 7‐Feed‐Array at the 100‐m telescope in Effelsberg will be used to perform an unbiased fully sampled HI survey of the full northern hemisphere observing both the galactic and extragalactic sky in parallel.
The use of FPGA‐based digital Fast Fourier transform spectrometers allows a sophisticated RFI detection scheme. Software to carry out stray‐radiation correction, RFI mitigation, and source detection is already working, as well as a C‐implementation of the least‐squares frequency switching (LSFS) scheme for the bandpass calibration.
The survey data will be very valuable for a broad range of scientific research areas, e.g. the study of the low‐mass end of the HI mass function (HIMF) in the local volume, as well as environmental and evolutionary effects on the HIMF, the search for galaxies near low‐redshift Ly‐α absorbers, the analysis of multiphase and extraplanar gas, HI shells, and Ultra Compact High Velocity Clouds.
