Method and apparatus for location information acquisition in GNSS shadow area using drones including prism

A location information acquisition method of a computing device, comprising the steps of:

• acquiring first location information at which an electro-optical topographic surveying device is located in response to a received Global Navigation Satellite System (GNSS) satellite signal;
• acquiring photography information for positioning of a target object photographed by a drone while the drone is flying in a GNSS shadow area from the drone equipped with a survey prism that reflects light waves from the surveying device;
• calculating absolute coordinates of the drone corresponding to the surveying device based on reflective metering of the survey prism and the photography information for positioning;
• calculating GNSS based second location information as location information of the target object using the absolute coordinates and the first location information;
• determining a first point at which the drone is currently located as a reference point, and controlling relative location change movement of the drone on the basis of the reference point when a grey zone is identified, the grey zone in which a reflective metering strength of the survey prism is equal to or less than a threshold;
• and
• estimating and calculating the absolute coordinates of the drone located at the grey zone using a change in reflective metering strength of the survey prism detected with the relative location change movement of the drone,
• wherein
• the photography information for positioning includes at least one of a photography image of the target object or an orthomosaic image using the photography image,
• the photography information for positioning includes the photography image of the target object and further includes photographing time information corresponding to the photography image,
• the surveying device includes a plurality of surveying devices disposed at a plurality of preset locations at which GNSS signals are received,
• the step of calculating the absolute coordinates comprises the step of processing synchronization correction of the photographing time information using a preset weight matrix table for each location range by bundle block adjustment according to a relative coordinate relationship between the plurality of surveying devices,
• the preset weight matrix table comprises pre-calculated weight values for each bundle block, and
• the photographing time is a data acquisition time of survey data, and the data acquisition time is corrected based on the pre-calculated weight values.