A method for detecting entities based on movement, the method comprising: transmitting a stepped-frequency radar signal from a first side of a wall to a second side of the wall; detecting reflections of the transmitted signal (115A, 120A, 125A, 130A) with an antenna (114, 116, 160, 210, 510A-530A) while the antenna (114, 116, 160, 510A-530A) is in motion; determining one or more characteristics of motion of a system (110, 150, 802A) which includes the antenna (114, 116, 160, 210, 510A-530A) during the detection of reflections of the transmitted signal (115A, 120A, 125A, 130A), wherein determining the one or more characteristics of the motion of the system (110, 150, 802A) includes receiving an indication of the one or more characteristics of the motion of the system (110, 150, 802A) from a motion sensor included within the system (110, 150, 802A), wherein receiving an indication of the one or more characteristics of the motion of the system (110, 150, 802A) from the motion sensor includes receiving information from an inertial sensor; generating data including information associated with frequency and phase shifts between the transmitted signal and the reflections of the transmitted signal (115A, 120A, 125A, 130A) detected with the antenna (114, 116, 160, 210, 510A-530A) while the antenna (114, 116, 160, 210, 510A-530A) is in motion; and analyzing the generated data to determine information associated with a moving object (115, 120, 125, 130, 640A, 740) located beyond the second side of the wall, the analyzing including using the determined one or more characteristics of the motion of the system (110, 150, 802A) to compensate for the effect of the motion of the system (110, 150, 802A) on the phase shifts between the transmitted signal and the reflections of the transmitted signal (115A, 120A, 125A, 130A). transmitting a stepped-frequency radar signal from a first side of a wall to a second side of the wall; detecting reflections of the transmitted signal (115A, 120A, 125A, 130A) with an antenna (114, 116, 160, 210, 510A-530A) while the antenna (114, 116, 160, 510A-530A) is in motion; determining one or more characteristics of motion of a system (110, 150, 802A) which includes the antenna (114, 116, 160, 210, 510A-530A) during the detection of reflections of the transmitted signal (115A, 120A, 125A, 130A), wherein determining the one or more characteristics of the motion of the system (110, 150, 802A) includes receiving an indication of the one or more characteristics of the motion of the system (110, 150, 802A) from a motion sensor included within the system (110, 150, 802A), wherein receiving an indication of the one or more characteristics of the motion of the system (110, 150, 802A) from the motion sensor includes receiving information from an inertial sensor; generating data including information associated with frequency and phase shifts between the transmitted signal and the reflections of the transmitted signal (115A, 120A, 125A, 130A) detected with the antenna (114, 116, 160, 210, 510A-530A) while the antenna (114, 116, 160, 210, 510A-530A) is in motion; and analyzing the generated data to determine information associated with a moving object (115, 120, 125, 130, 640A, 740) located beyond the second side of the wall, the analyzing including using the determined one or more characteristics of the motion of the system (110, 150, 802A) to compensate for the effect of the motion of the system (110, 150, 802A) on the phase shifts between the transmitted signal and the reflections of the transmitted signal (115A, 120A, 125A, 130A).