An autonomous mobile work system for performing work in a designated area, the system comprising: a first variable reflectivity base station, the base station being configured to change its reflectivity; and an autonomous mobile work device including at least one sensor characterized in that the work system further comprises a second variable reflectivity base station: each of the first and second variable reflectivity base stations comprises a radar reflector having a variable radar cross section; and the autonomous mobile work system is configured to; provide a location of the first variable reflectivity base station to the autonomous mobile work device; change an electromagnetic reflectivity state of the first variable reflectivity base station in response to a command from the mobile work device; calculate a first distance between the first variable reflectivity base station and the autonomous mobile work device: provide a location of the second variable reflectivity base station to the autonomous mobile work device; change an electromagnetic reflectivity state of the second variable reflectivity base station in response to a command from the mobile work device; calculate a second distance between the second variable reflectivity base station and the autonomous mobile work device; and determine a first location of the autonomous mobile work device based on the provided locations of the first and second variable reflectivity base stations and the calculated distances to the first and second variable reflectivity base stations. a first variable reflectivity base station, the base station being configured to change its reflectivity; and an autonomous mobile work device including at least one sensor characterized in that the work system further comprises a second variable reflectivity base station: each of the first and second variable reflectivity base stations comprises a radar reflector having a variable radar cross section; and the autonomous mobile work system is configured to; provide a location of the first variable reflectivity base station to the autonomous mobile work device; change an electromagnetic reflectivity state of the first variable reflectivity base station in response to a command from the mobile work device; calculate a first distance between the first variable reflectivity base station and the autonomous mobile work device: provide a location of the second variable reflectivity base station to the autonomous mobile work device; change an electromagnetic reflectivity state of the second variable reflectivity base station in response to a command from the mobile work device; calculate a second distance between the second variable reflectivity base station and the autonomous mobile work device; and determine a first location of the autonomous mobile work device based on the provided locations of the first and second variable reflectivity base stations and the calculated distances to the first and second variable reflectivity base stations. each of the first and second variable reflectivity base stations comprises a radar reflector having a variable radar cross section; and the autonomous mobile work system is configured to; provide a location of the first variable reflectivity base station to the autonomous mobile work device; change an electromagnetic reflectivity state of the first variable reflectivity base station in response to a command from the mobile work device; calculate a first distance between the first variable reflectivity base station and the autonomous mobile work device: provide a location of the second variable reflectivity base station to the autonomous mobile work device; change an electromagnetic reflectivity state of the second variable reflectivity base station in response to a command from the mobile work device; calculate a second distance between the second variable reflectivity base station and the autonomous mobile work device; and determine a first location of the autonomous mobile work device based on the provided locations of the first and second variable reflectivity base stations and the calculated distances to the first and second variable reflectivity base stations. provide a location of the second variable reflectivity base station to the autonomous mobile work device; change an electromagnetic reflectivity state of the second variable reflectivity base station in response to a command from the mobile work device; calculate a second distance between the second variable reflectivity base station and the autonomous mobile work device; and determine a first location of the autonomous mobile work device based on the provided locations of the first and second variable reflectivity base stations and the calculated distances to the first and second variable reflectivity base stations.