A method of providing a relative navigation system comprising: projecting into space from a second object a grid (170, 190) comprised of a plurality of grid lines, the grid (170, 190) originating from a second origin point, or from a known location spaced from a second origin point, of a second relative reference frame associated with the second object; repeatedly detecting, using a detector array comprising a plurality of non-collinearly arranged detector modules of a first object, the grid lines from the first object having a first relative reference frame associated with a first origin point on the first object; repeatedly determining the range from the second object to the first object based on the grid lines, determining the range comprising either: counting a number of bit transitions of a grid word detected at each detector module, wherein the plurality of grid lines are encoded with different grid words in different regions of the grid (170, 190) to indicate regions within the grid (170, 190), the encoding of the grid word occurring by modulating a beam used to form the grid lines; or counting a number of lines seen by one or more of the detector modules; repeatedly determining over time the relative attitude between the first and second relative reference frames to form a plurality of relative attitudes, determining the relative attitude comprising determining a distance from each detector module to the second object; and adjusting at least one of the attitude and range of at least one of the first and second objects based on the determined range and relative attitude; wherein both of the first and second objects are moving objects and wherein one of the first and second objects is a target vehicle and the other of the first and second objects is a chase vehicle. projecting into space from a second object a grid (170, 190) comprised of a plurality of grid lines, the grid (170, 190) originating from a second origin point, or from a known location spaced from a second origin point, of a second relative reference frame associated with the second object; repeatedly detecting, using a detector array comprising a plurality of non-collinearly arranged detector modules of a first object, the grid lines from the first object having a first relative reference frame associated with a first origin point on the first object; repeatedly determining the range from the second object to the first object based on the grid lines, determining the range comprising either: counting a number of bit transitions of a grid word detected at each detector module, wherein the plurality of grid lines are encoded with different grid words in different regions of the grid (170, 190) to indicate regions within the grid (170, 190), the encoding of the grid word occurring by modulating a beam used to form the grid lines; or counting a number of lines seen by one or more of the detector modules; counting a number of bit transitions of a grid word detected at each detector module, wherein the plurality of grid lines are encoded with different grid words in different regions of the grid (170, 190) to indicate regions within the grid (170, 190), the encoding of the grid word occurring by modulating a beam used to form the grid lines; or counting a number of lines seen by one or more of the detector modules; repeatedly determining over time the relative attitude between the first and second relative reference frames to form a plurality of relative attitudes, determining the relative attitude comprising determining a distance from each detector module to the second object; and adjusting at least one of the attitude and range of at least one of the first and second objects based on the determined range and relative attitude; wherein both of the first and second objects are moving objects and wherein one of the first and second objects is a target vehicle and the other of the first and second objects is a chase vehicle.