DETERMINING TILT ANGLE AND TILT DIRECTION USING IMAGE PROCESSING

A method of determining a tilt angle and a tilt direction of a survey instrument includes capturing first images at a first location that include features from an environment around the survey instrument and capturing second images at a second location that include a portion of the features. A pose of the imaging device is determined at the second location using observed changes in location of a common portion of the features between the first images and the second images. The tilt angle and the tilt direction of the survey instrument at the second location are determined using the pose of the imaging device.