１７．曳航体、ROV（Towfish - ROV）
Q. 曳航体の動きについての考え方(Towed Object Layback Method in Hypack® Max)[英語]
During a recent training session, the towed object tracking in Hypack® was discussed with several of the Hypack® users in the class. The problem with monitoring a towed object such as a magnetometer or side scan has always been trying to approximate the actual track of the object in relation to the vessel towing the object.
After investigating the method used, a decision was made to improve the track of the towed object by using the course made good as a reference to the actual heading of the object. This worked better, but was found to be lacking a bit in the expected track of the object, so we have written a new algorithm to calculate the position.
As the vessel moves ahead, a new circle is generated. The intersection of the circle and the track of the fish is then computed as the new position of the fish. The heading of the fish is the azimuth from the fish to the boat. We are still fine tuning the calculations to get a more accurate position of the fish. At this point I am much happier about the location of the towed object tracking and would recommend this method over the previous method of calculating the layback position.
If you would like the new driver I can either e-mail it to you or it can be obtained by downloading the latest Service Pack from the internet.
Below I have included a sample image of a screen capture showing both the old and new methods of tracking a towed object. This is a worst case scenario and was meant to show a dramatic effect of layback.