Automatic scope zoom sensing for rifle mounted clip-on fire control displays

1. An automatic zoom-sensing method for a riflescope display adapter (RDA), the method comprising:

illuminating an iris of a user with a beam from a light emitter;

activating a display comprising at least one graphical element visible by the user through an eyepiece;

focusing an image of the iris on a sensor;

determining a diameter of the iris from the image of the iris using an iris analyzer;

developing a calibration table that correlates the diameter of the iris to a zoom level of an optical scope;

estimating the zoom level of the optical scope from the diameter of the iris via the calibration table; and

adjusting, to match the zoom level, a font size of the at least one graphical element on the display.

2. The automatic zoom-sensing method of claim 1 , wherein developing the calibration table comprises:

receiving a first input from the user, the first input specifying a minimum zoom level for the optical scope;

determining the diameter of the iris of the user at the minimum zoom level;

receiving a second input from the user, the second input specifying a maximum zoom level for the optical scope; and

determining the diameter of the iris of the user at the maximum zoom level.

3. The automatic zoom-sensing method of claim 1 , wherein the RDA removably attaches to the optical scope.

4. The automatic zoom-sensing method of claim 1 , wherein the sensor is a camera or a focal plane array.

5. The automatic zoom-sensing method of claim 1 , further comprising:

authenticating an authorized user based on the diameter of the iris;

upon authenticating the authorized user, unlocking the RDA.

6. The automatic zoom-sensing method of claim 1 , wherein activating the display comprises illuminating the display with a beam from a visible light emitting diode (LED).

7. The automatic zoom-sensing method of claim 1 , wherein the light emitter is an infrared (IR) illuminator.

8. An automatic zoom-sensing riflescope display adapter (RDA) system comprising:

a light emitter configured to illuminate an iris of a user with a beam;

a display comprising at least one graphical element visible by the user through an eyepiece;

a sensor configured to focus an image of the iris; and

an RDA controller communicatively coupled to the light emitter, the display, and the sensor and configured to perform operations comprising:

determining a diameter of the iris from the image of the iris using an iris analyzer,

activating the display,

developing a calibration table that correlates the diameter of the iris to a zoom level of an optical scope,

estimating the zoom level of the optical scope from the diameter of the iris via the calibration table, and

adjusting, to match the zoom level, a font size of the at least one graphical element on the display.

9. The RDA system of claim 8 , wherein developing the calibration table comprises:

receiving a first input from the user, the first input specifying a minimum zoom level for the optical scope;

determining the diameter of the iris of the user at the minimum zoom level;

receiving a second input from the user, the second input specifying a maximum zoom level for the optical scope; and

determining the diameter of the iris of the user at the maximum zoom level.

10. The RDA system of claim 8 , wherein the RDA removably attaches to an optical scope.

11. The RDA system of claim 8 , wherein the sensor is a camera or a focal plane array.

12. The RDA system of claim 8 , the operations further comprising:

authenticating an authorized user based on the diameter of the iris; and

upon authenticating the authorized user, unlocking the RDA.

13. The RDA system of claim 8 , wherein activating the display comprises illuminating the display with a beam from a visible light emitting diode (LED).

14. The RDA system of claim 8 , wherein the light emitter is an infrared (IR) illuminator.

15. A non-transitory computer-readable medium comprising instructions executable by a riflescope display adapter (RDA) controller of an automatic zoom-sensing RDA for causing the RDA controller to perform operations comprising:

determining a diameter of the iris from the image of the iris using an iris analyzer;

activating the display;

developing a calibration table that correlates the diameter of the iris to a zoom level of an optical scope;

estimating the zoom level of the optical scope from the diameter of the iris via the calibration table; and

adjusting, to match the zoom level, a font size of the at least one graphical element on the display.

16. The non-transitory computer-readable medium of claim 15 , wherein developing the calibration table comprises:

receiving a first input from the user, the first input specifying a minimum zoom level for the optical scope;

determining the diameter of the iris of the user at the minimum zoom level;

receiving a second input from the user, the second input specifying a maximum zoom level for the optical scope; and

determining the diameter of the iris of the user at the maximum zoom level.

17. The non-transitory computer-readable medium of claim 15 , wherein the RDA removably attaches to an optical scope.

18. The non-transitory computer-readable medium of claim 15 , wherein the tracking sensor is a camera or a focal plane array.

19. The non-transitory computer-readable medium of claim 15 , the operations further comprising:

authenticating an authorized user based on the diameter of the iris; and

upon authenticating the authorized user, unlocking the RDA.

20. The non-transitory computer-readable medium of claim 15 , wherein the display is a visible light emitting diode (LED) display.