Attitude estimation apparatus, attitude estimation method, and observation system

An observation system comprising an observation apparatus and an attitude estimation apparatus which operates in cooperation with the observation apparatus,

• the observation apparatus including:
• a positioning device configured to output positioning data indicating a position of a flying object in a geodetic coordinate system;
• a ranging device configured to measure a distance from the flying object to a range-measurement point located on a ground and measure an angular direction with respect to the range-measurement point, to thereby output ranging data;
• an imaging unit configured to capture images of the range-measurement point as seen from a plurality of imaging positions while incorporated in the flying object and output the captured images;
• and an attitude sensor configured to detect an attitude of the flying object with respect to a gravitational direction, to thereby output actual attitude data, and
• the attitude estimation apparatus including information processing circuitry configured to:
• acquire the positioning data, the ranging data, the actual attitude data, and the captured images from the observation apparatus;
• calculate geodetic coordinates indicating a position of the range-measurement point in the geodetic coordinate system, using the positioning data, the ranging data, the actual attitude data, and estimated values of one or more unknown parameters representing the attitude of the flying object;
• calculate coordinates of a projected point by performing a projection transformation of the geodetic coordinates from the geodetic coordinate system to an image coordinate system;
• perform image matching between a first captured image and a second captured image which are selected from the captured images, to thereby to detect image coordinates of the range-measurement point appearing in the first captured image;
• and
• correct the estimated values to thereby reduce an absolute difference between the coordinates of the projected point and the image coordinates.

An attitude estimation method to be executed in an attitude estimation apparatus which operates in cooperation with an observation apparatus comprising:

• a positioning device configured to output positioning data indicating a position of a flying object in a geodetic coordinate system;
• a ranging device configured to measure a distance from the flying object to a range-measurement point located on a ground and measure an angular direction with respect to the range-measurement point, to thereby output ranging data;
• an imaging unit configured to capture images of the range-measurement point as seen from a plurality of imaging positions while incorporated in the flying object and output the captured images;
• and an attitude sensor configured to detect an attitude of the flying object with respect to a gravitational direction, to thereby output actual attitude data,
• the attitude estimation method comprising the steps of:
• acquiring the positioning data, the ranging data, the actual attitude data, and the captured images from the observation apparatus;
• calculating geodetic coordinates indicating a position of the range-measurement point in the geodetic coordinate system using the positioning data, the ranging data, the actual attitude data, and estimated values of one or more unknown parameters representing the attitude of the flying object;
• calculating coordinates of a projected point by performing a projection transformation of the geodetic coordinates from the geodetic coordinate system to an image coordinate system;
• performing image matching between a first captured image and a second captured image which are selected from the captured images, to thereby detect image coordinates of the range-measurement point appearing in the first captured image;
• and
• correcting the estimated values to thereby reduce an absolute difference between the coordinates of the projected point and the image coordinates.