A guide light irradiation device to irradiate guide light to indicate a direction to a survey operator, includes a plurality of irradiators configured to each irradiate guide light differing in pattern between the left and the right of an irradiation direction as a center, the plurality of irradiators are juxtaposed in the up-down direction, and are disposed so that irradiation directions of the respective irradiators match in the horizontal direction, and make a predetermined angle with each other in the vertical direction. Synthetic light of guide lights irradiated from the respective irradiators has brightness as a sum of brightnesses of light sources of the respective irradiators, and has a fan shape extending in the vertical direction. A distance from which light is visually recognized is long, and guide light is easily found even at a location with level differences.

A guide light irradiation device to irradiate guide light to indicate a direction to a survey operator, includes a plurality of irradiators configured to each irradiate guide light differing in pattern between the left and the right of an irradiation direction as a center, the plurality of irradiators are juxtaposed in the up-down direction, and are disposed so that irradiation directions of the respective irradiators match in the horizontal direction, and make a predetermined angle with each other in the vertical direction. Synthetic light of guide lights irradiated from the respective irradiators has brightness as a sum of brightnesses of light sources of the respective irradiators, and has a fan shape extending in the vertical direction. A distance from which light is visually recognized is long, and guide light is easily found even at a location with level differences.

A guide light irradiation device to irradiate guide light to indicate a direction to a survey operator, includes a plurality of irradiators configured to each irradiate guide light differing in pattern between the left and the right of an irradiation direction as a center, the plurality of irradiators are juxtaposed in the up-down direction, and are disposed so that irradiation directions of the respective irradiators match in the horizontal direction, and make a predetermined angle with each other in the vertical direction. Synthetic light of guide lights irradiated from the respective irradiators has brightness as a sum of brightnesses of light sources of the respective irradiators, and has a fan shape extending in the vertical direction. A distance from which light is visually recognized is long, and guide light is easily found even at a location with level differences.

A guide light irradiation device to irradiate guide light to indicate a direction to a survey operator, includes a plurality of irradiators configured to each irradiate guide light differing in pattern between the left and the right of an irradiation direction as a center, the plurality of irradiators are juxtaposed in the up-down direction, and are disposed so that irradiation directions of the respective irradiators match in the horizontal direction, and make a predetermined angle with each other in the vertical direction. Synthetic light of guide lights irradiated from the respective irradiators has brightness as a sum of brightnesses of light sources of the respective irradiators, and has a fan shape extending in the vertical direction. A distance from which light is visually recognized is long, and guide light is easily found even at a location with level differences.

A guide light irradiation device to irradiate guide light to indicate a direction to a survey operator, includes a plurality of irradiators configured to each irradiate guide light differing in pattern between the left and the right of an irradiation direction as a center, the plurality of irradiators are juxtaposed in a left-right direction, and irradiation units of the plurality of irradiators are disposed so that the irradiation units match in the horizontal direction, and optical axes of the plurality of irradiators make a predetermined angle with each other in the vertical direction. Synthetic light of the respective guide lights has brightness obtained by summing brightnesses of the light sources of the respective irradiators, and has a fan shape extending in the vertical direction. A distance at which the light is visually recognized is long, and the guide light is easily found even at a location with level differences.

A guide light irradiation device to irradiate guide light to indicate a direction to a survey operator, includes a plurality of irradiators configured to each irradiate guide light differing in pattern between the left and the right of an irradiation direction as a center, the plurality of irradiators are juxtaposed in a left-right direction, and irradiation units of the plurality of irradiators are disposed so that the irradiation units match in the horizontal direction, and optical axes of the plurality of irradiators make a predetermined angle with each other in the vertical direction. Synthetic light of the respective guide lights has brightness obtained by summing brightnesses of the light sources of the respective irradiators, and has a fan shape extending in the vertical direction. A distance at which the light is visually recognized is long, and the guide light is easily found even at a location with level differences.

Embodiments described herein are directed to an apparatus for determining a direction in which a tree will fall and a method for using the apparatus. The apparatus may comprise a plate including a substantially straight edge suitable for alignment with a vertex formed by a top cut and a bottom cut of a notch cut into a tree and a substantially level bottom surface suitable for stable placement upon the bottom cut of the notch. In some embodiments, the plate may define an internal cavity sized to accommodate a laser light generator. In other embodiments, a rotatable housing including a cavity sized to accommodate a laser light generator may be adjoined to the plate. Embodiments may permit a laser light generator contained within the cavity or the housing to emanate a beam of laser light in a direction that is substantially perpendicular to the substantially straight edge of the plate.

Current GNSS-inclinable surveying pole systems rely on magnetometer sensors. The use of these types of sensor implies performance degradation when operating near magnetic fields. The invention provides a new approach to ranging pole systems, able to provide requested performance even when working near magnetic fields.

Current GNSS-inclinable surveying pole systems rely on magnetometer sensors. The use of these types of sensor implies performance degradation when operating near magnetic fields. The invention provides a new approach to ranging pole systems, able to provide requested performance even when working near magnetic fields.

The present invention provides a ruler, comprising a first ruler body and a second ruler body, wherein the first ruler body and the second ruler body are connected in a relatively rotatable manner to enable both leveled and perpendicular connections of the first ruler body and the second ruler body.