JPS6318943Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention relates to a positioning device that obtains a position line from a Loran receiver, NNSS, etc., and automatically calculates it based on the current position of the own ship. to evaluate the reliability of the current location.
This invention relates to display devices.

Position lines obtained from Loran receivers, NNSS, etc. contain various error factors, so it is highly unlikely that all position lines intersect at one point. For example, in NNSS, up to 40 position lines can be obtained by measuring using the so-called shot Doppler method, but the intersections of these position lines are scattered within a certain range around the correct position. .

Therefore, in the past, all position lines were used to find the position using a statistical method, often by the least squares method. By simultaneously displaying the number of lines, the maximum elevation angle of the satellite, the symmetry of the position line with respect to the maximum elevation angle, or the residual by the least squares method, observers can indirectly judge the reliability of the positioning results. I was doing it.

However, these scale elements, which have been conventionally evaluated, cannot be said to have a sufficient correlation with reliability and cannot be used as definitive evaluation targets. For example, even if many position lines are obtained, if some of them are far away from the estimated position, generally those partial position lines should be excluded from evaluation, but the total number of position lines is evaluated. This is because such a partial position line can also be regarded as an evaluation target having a certain weight.

This invention was made in view of the above, and aims to provide a positioning result display device that makes use of human pattern recognition ability to more accurately determine the reliability of positioning results.

Examples of this invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a display device which is an embodiment of this invention.

In the figure, 1 is the NNSS receiver, 2 is the Loran C receiver, and the output data from these two receivers (position line measuring devices) with different geodetic systems is sent to the arithmetic unit 3 using a microcomputer. The position line display data is then sent. The CRT 4 is a display means for graphically displaying the position line display data, and display control is performed by a display control circuit 5.

FIG. 2 is a flowchart showing the procedure executed by the arithmetic unit 3.

Step n ₁ (hereinafter step n _x is simply referred to as n _x )
When a signal is received at n ₂ , the receiving device is identified. The position line of the current position is measured from the data obtained by each receiver using n ₃ or less for NNSS and n ₁₁ or less for Loran C transmitter.

First, in _n3 , the distance difference between the satellite and the ship, that is, the measured position line _D1 , is calculated from the dop count value. Next, the satellite position is determined from the orbit parameters at _n4 , and the estimated position corresponding to this dimension is determined at _n5 . then n ₆
Find the position line variation per unit movement of the ship's position for each latitude and longitude, and use n ₇ to calculate the estimated position line.
_D2 is calculated, and from these values, ΔD is calculated at _n8 , and the position line of the current position is calculated at _n9 .

Normally, the above procedure is executed every 20 seconds to 2 minutes, and when the received signal ends, the process proceeds to _n19 .

On the other hand, if the received signal is a Loran signal, the position line of the current position is determined from _n11 and below using the same procedure as described above. That is, the position line T ₁ is measured at n ₁₁ , and the position line T ₂ of the estimated position set at n ₁₃ from the station position of the used chain is calculated at n ₁₅ , while at n ₁₄
Find the position line variation per unit movement of the ship's position for each latitude and longitude, and from these values, calculate △T with n ₁₆
At the same time, calculate the position line of the current position using _n17 . When all position line measurements are completed, proceed to n ₁₉ .

At _n19 , the position is determined by the method of least squares using all the position lines obtained as described above. Then, with n ₂₀ , all the position lines centered at that position are
Display on CRT4 and return to the beginning with each position line displayed at the same time.

FIGS. 3A and 3B show examples of display modes obtained on the CRT 4 through the above operations.

As is clear from the figure, the distribution pattern of the position lines shown in A has a greater degree of variation than the distribution pattern in B. Therefore, it can be determined that the reliability of the positioning results obtained by the least squares method is higher in the case shown in B than in A in the same figure.

As described above, according to this invention, it is possible to qualitatively understand the bias, variation, etc. of the obtained position line distribution pattern, so that the degree of reliability of the positioning result can be intuitively determined. In addition, since the position line measuring device is constituted by a plurality of position line measuring devices having different geodetic systems, it is possible to prevent the distribution pattern of the displayed position lines from being biased in particular. Furthermore, from among the displayed position lines, remove the position lines that are far away from the estimated position, extract only the position lines that are close to the estimated position, select them using the input keys, etc., and again select at least 2 lines from those position lines. If the results are obtained by multiplication, even if the distribution patterns of all position lines have a large divergence, there is an advantage that positioning results with as small an error as possible can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a display device that is an embodiment of this invention, and FIG. 2 is a flowchart showing the operation of the device. Further, FIGS. 3A and 3B show display examples of the same device, respectively.

Claims (1)

[Scope of utility model registration request] A positioning result characterized by comprising: a plurality of position line measuring devices with different geodetic systems; and a display means for simultaneously graphically displaying a plurality of position lines obtained by each of these position line measuring devices on the same screen. Display device.