Telescope-attachable sensors comprised of built-in sensors, namely, tilt sensor, GPS, magnetic sensor, distance sensor, temperature sensor, pressure sensor for measuring altitude, geographic position, environmental temperature of telescope location, elevation angle, orientation, distance of the target viewed with the scope, for use in the areas of hunting, archery, target shooting, golfing, hiking, construction, surveying, rescuing; telescope-attachable sensors with built-in ballistic calculation units and built-in sensors, namely, tilt sensor, GPS, magnetic sensor, distance sensor, temperature sensor, pressure sensor for measuring altitude, geographic position, environmental temperature of telescope location, elevation angle, orientation, distance of the target viewed with the scope, for calculating the ballistics of flying objects, namely, bullets, arrows, golf balls, from pre-stored motion coefficients, and environmental-orientational parameters measured by the built-in electronic sensors, for use in the areas of hunting, target shooting, archery and golfing; telescope-mountable sensors with built-in geometric calculation units and built-in sensors, namely, tilt sensor, GPS, magnetic sensor, distance sensor, temperature sensor, pressure sensor for measuring altitude, geographic position, environmental temperature of telescope location, elevation angle, orientation, distance of the target viewed with the scope, for calculating the location, orientation, elevation angles, distances between various targets viewed with the scope, for use in the areas of hunting, golfing, hiking, construction, surveying, rescuing