A highly accurate and versatile weapon alignment solution

11 June 2020 (Last Updated June 11th, 2020 10:51)

Sponsored by Schill Reglerteknik Sponsored by Visit Company

Recent trend in weapon alignment

Combat and tactical land vehicles, including trucks, are usually armed with remotely controlled weapon station (RCWS). The crew protection advantage is obvious without compromising the functionality. The typical RCWS combines a gun with search and tracking sensors integrated on the same mount.

Naval vessels are equipped with many different weapons such as guns, missiles and torpedoes. Search and tracking sensors are mostly located separately and can often be used in varying combinations with the weapons. However, a new generation of guns has a camera integrated on the gun-mount instead of the traditional manual sight. In addition, autonomic RCWS may co-exist with centrally controlled weapon systems. On smaller patrol crafts, RCWS with integrated sensors and gun is often the main weaponry.

Common to all weapon systems is the necessity to align the weapons with the sensors. So, the latest advancements in search, tracking and situational awareness would be of limited value if the targets could not be successfully engaged. To fully take advantage of the recent development, the trend is to perform and verify weapon alignment more frequently than before. Consequently, alignment of RCWS, gun-sight cameras and a mixture of separate and integrated sensors and weapons requires versatile and accurate tools, which support swift and efficient procedures for use in the workshop and in the field.

Boresight telescope versus boresight camera

Boresight telescopes are widely used for gun alignment. The main problem is the personal safety hazard involved with using the telescope on a gun, which is tested under servo control. In contrast, a boresight camera can be used regardless of the model of the gun without imposing any risks to its user. In addition, a camera system enables the presentation of video from more than one platform on the same screen for direct comparison between a tracker camera and a gun camera. This advantage can be even further exploited in Schill’s computerised alignment systems featuring automatic optical target tracking in multiple windows and evaluation of the corresponding alignment errors.

The importance of the gun adapter (calibre bar) design

A common gun adapter design is based on a three-point expansion mechanism located at each end of the bar for aligning and fastening the adapter inside the gun barrel. The advantage is that it is relatively easy to produce. The drawback is a significant sensitivity for even minor wear and damages inside the barrel. Minor damage inside the barrel, displacing one end of the gun adapter by one millimetre, will result in an alignment error of 2mrad on a 0.5m gun adapter regardless of the calibre of the gun. Such a magnitude of alignment error is unacceptable.

The gun adapters manufactured by Schill have a unique design unaffected by wear, damages and rifling. The mounting repetition accuracy of the gun adapters is extremely high (higher than 0.05mrad). In addition, the design entails an unmatched friction force, keeping the gun adapter safely attached inside the barrel and making safety straps superfluous.

Alignment methods

Alignment of the camera to the gun bore, where the camera is located on the same mount as the gun (the RCWS or the new generation of guns), can be made in three different ways using a long-range target, a short-range target or by collimation.

A long-range target test using a boresight camera and a gun adapter (calibre bar) is the best choice for field use, especially under dynamic conditions. Schill’s boresight camera can be combined with several adapters, which makes a very cost-efficient solution.

Figure 1 – Alignment of a sensor (gun-sight camera) to the gun barrel. Applicable for both long and short-range targets under dynamic and static conditions.

Tests using a boresight camera and an alignment board at a short range are suitable for workshop areas. The alignment board enables the use of target patterns designed for the sight-gun bore displacement, eliminating parallax errors.

Alignment by collimation is an excellent method for both field and workshop use. No targets are required and the sensor (camera) to be aligned shall be focused at infinity, just as in normal usage mode. A collimator (instead of a camera) is simply mounted to the gun adapter (calibre bar).

Figure 2 – Alignment of a sensor (gun-sight camera) to the gun barrel using collimation.

Naturally, Schill’s alignment tools fully support the three alignment methods discussed above. Moreover, Schill offers complete systems for both static and dynamic alignment of all naval weapon systems in any configuration.

Summary

A recent trend is to align sensors and weapons more frequently than before to take advantage of all the advancements in weapon system technology. This requires alignment tools, which support swift and efficient procedures for use both in the workshop and in the field.

The accuracy and versatility of Schill’s alignment tools cover a wide range of applications, for example:

  • Alignment of a gun-sight camera – gun barrel
  • Alignment of RCWS
  • Alignment of weapon platforms on separately located mounts

It also covers these methods:

  • Long-range targets
  • Short-range targets
  • Collimation

About Schill Reglerteknik

Schill Reglerteknik AB is a market leader in supplying weapon alignment products and services. The Swedish company was founded in 1986 and has since been supplying its products in more than 25 countries around the world. Their customers include weapon system original equipment manufacturers (OEMs) and integrators, shipyards and navies.