Magnetic Heading Effect Clause Samples

Magnetic Heading Effect. The magnetic heading effect will be determined prior to the survey by flying a cloverleaf pattern oriented in the same direction as the survey lines and tie lines at high level in an area with low magnetic gradient. At least two passes in each direction will be flown in order to obtain sufficient statistical information to estimate the heading error. The heading error will be determined at the beginning of the survey, and again if there are any modifications or additions to the aircraft or the equipment installed in it. A lag test will have been performed before the survey to ascertain the time difference between the instrument readings and the operation of the GPS System. Test lines are flown in two directions at survey altitude across distinct anomalies. These lag tests were carried out before the start of survey production flights, and will be repeated after any major survey equipment alteration or replacement has been made.