Abstract: Armored vehicles, weapon measurement system, and methods for determining barrel elevation of a gun, are provided. In one example, an armored vehicle includes a vehicle body portion and a gun having a barrel extending away from the vehicle body portion at a barrel elevation angle. A weapon measurement system includes a reference light generator arrangement configured to generate a reference light at a single wavelength or within a narrow wavelength band and to diffuse the reference light, thereby defining a distributed reference light. An image sensor arrangement includes an image sensor and a filter. The filter is configured to substantially block light that is at a different wavelength than the distributed reference light while allowing the distributed reference light to pass through to the image sensor for determining the barrel elevation angle.