When intersecting lines of position are used to fix the position of an unmapped feature or point by fixing its position relative to two ( or more ) mapped or known points, the method is known as " intersection ".
32.
Each station transmitted a continuous wave signal that, by comparing the phase difference of the signals from the Master and one of the Slaves, resulted in a set of hyperbolic " lines of position " called a " pattern ".
33.
When a vessel is within radar range of land or special radar aids to navigation, the navigator can take distances and angular bearings to charted objects and use these to establish arcs of position and lines of position on a chart.
34.
Since the wavelength of the common frequency was small compared with the distance between the Master and Slave stations there were many possible lines of position for a given phase difference, and so a unique position could not be arrived at by this method.
35.
The last transmission received from Earhart indicated she and Noonan were flying along a line of position ( taken from a " sun line " running on 157 337 degrees ) which Noonan would have calculated and drawn on a chart as passing through Howland.
36.
A single transmitter can be used to give a line of position ( LOP ) of the craft . The ( true ) bearing to the station from the craft, TB or QUJ, is composed of the true heading, TH, plus the relative bearing, RB, of the station.
37.
The last voice transmission received on Howland Island from Earhart indicated she and Noonan were flying along a line of position ( taken from a " sun line " running on 157 337 degrees ) which Noonan would have calculated and drawn on a chart as passing through Howland.
38.
Since he did not know in advance when he would arrive at a line of position passing through his destination, he pre-calculated a table or graph of the Sun's altitude and azimuth at his destination for a range of times bracketing his ETA . The advantage of this method was that the effects of drift were reduced to errors in distance travelled, usually much smaller.
39.
They have suggested Earhart and Noonan may have flown without further radio transmissions for two and a half hours along the line of position Earhart noted in her last transmission received at Howland, then found the then-uninhabited Gardner Island, landed the Electra on an extensive reef flat near the wreck of a large freighter ( the ) on the northwest side of the atoll, and ultimately perished.
