WE CLAIM:
1. A method comprising:
receiving image data from a camera coupled to an air intake system of a gas turbine engine, wherein the image data corresponds to an air passage of the air intake system;
comparing the received image data to reference image data of the air intake system; and
generating an icing notification based at least in part on the comparison when a difference between the received image data and reference image data is greater than an icing threshold.
2. The method as claimed in claim 1, wherein the difference is greater than the icing threshold when the comparison indicates a threshold amount of ice accumulation on at least a portion of the air passage of the air intake system.
3. The method as claimed in claim 1, wherein comparing the received image data to the reference image data comprises matching reference fiducial markers of the reference image data to received fiducial markers of the received image data.
4. The method as claimed in claim 1, wherein comparing the received image data to the reference image data comprises:
determining a first edge of the air passage of the reference image data; determining a second edge of the air passage of the received image data; and
comparing the first edge to the second edge.

5. The method as claimed in claim 1, comprising controlling an air flow through the air passage based at least in part on the icing notification, wherein controlling the air flow comprises heating the air flow, bleeding a portion of the air flow from the air intake system, shutting down the air intake system, or any combination thereof.
6. The method as claimed in claim 5, comprising controlling the air flow through the air passage automatically based at least in part on the icing notification.
7. The method as claimed in claim 1, wherein the gas turbine engine comprises a compressor coupled to air intake system.
8. The method as claimed in claim 1, wherein the icing notification is based at least in part on icing data received from an ice detector coupled to the air passage.
9. The method as claimed in claim 1, wherein the icing notification comprises an audible notification, a visual notification, or any combination thereof.
10. The method as claimed in claim 1, wherein the received image data and the reference image data correspond to a bellmouth of the air intake system.
11. A system comprising:
a controller, comprising:

one or more tangible, non-transitory, machine-readable media collectively storing one or more sets of instructions; and
one or more processing devices configured to execute the one or more sets of instructions to:
receive image data from a camera coupled to an air intake system of a gas turbine engine, wherein the image data corresponds to an air passage of the air intake system;
compare the received image data to reference image data of the air intake system; and
generate an icing notification based at least in part on the comparison when a difference between the received image data and reference image data is greater than an icing threshold.
12. The system as claimed in claim 11, wherein the difference is greater than the icing threshold when the comparison indicates a threshold amount of ice accumulation on at least a portion of the air passage of the air intake system.
13. The system as claimed in claim 11, wherein the one or more processing devices are configured to execute the one or more sets of instructions to match reference fiducial markers of the reference image data to received fiducial markers of the received image data.
14. The system as claimed in claim 11, wherein the one or more processing devices are configured to:
determine a first edge of the air passage of the reference image data;
determine a second edge of the air passage of the received image data; and

compare the first edge to the second edge.
15. The system as claimed in claim 11, wherein the one or more processing devices are configured to control an air flow through the air passage based at least in part on the icing notification, wherein to control the air flow comprises to heat the air flow, to bleed a portion of the air flow from the air intake system, to shut down the air intake system, or any combination thereof.
16. The system as claimed in claim 11, wherein the one or more processing devices are configured to receive icing data from an ice detector coupled to the air passage and to generate the icing notification based at least in part on the icing data.
17. A system comprising:
a gas turbine engine comprising an air intake system, the air intake system comprising an air passage;
a camera coupled to the air intake system and configured to image the air passage of the air intake system; and
a controller communicatively coupled to the camera and configured to: receive image data from the camera, wherein the image data corresponds to the air passage;
compare the received image data to reference image data of the air intake system; and
generate an icing notification based at least in part on the comparison when a difference between the received image data and reference image data is greater than an icing threshold.

18. The system as claimed in claim 17, wherein the controller is configured to match reference fiducial markers of the reference image data to received fiducial markers of the received image data.
19. The system as claimed in claim 17, wherein the controller is configured to control an air flow through the air passage based at least in part on the icing notification, wherein to control the air flow comprises to heat the air flow, to bleed a portion of the air flow from the air intake system, to shut down the air intake system, or any combination thereof.
20. The system as claimed in claim 17, comprising an ice detector coupled to the air passage, and wherein the controller is configured to receive icing data from the ice detector and to generate the icing notification based at least in part on the icing data.