JPH0161167B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tide display device that calculates and displays tide levels using a harmonic decomposition method. An object of the present invention is to provide a basic configuration of a tidal display device as a small device.

Information on tides, that is, tidal ebb and flow phenomena, is important not only for those involved in fishing, but also for fishing enthusiasts, clam hunters, and others. Naturally, predictions of this information are obtained through highly accurate calculations using the harmonic decomposition method, and are published by the Japan Meteorological Agency and the Japan Coast Guard. Those seeking information can contact these offices or consult the materials published there. However, it is troublesome to ask them one by one, and even if you look at the materials, you will have to read the daily high tide time and tide level, and the low tide time and tide level at a specific location as numbers. For fishing enthusiasts, what they want to visualize in their minds is the tidal conditions in the area on any given day, and they are required to use that information to find the optimal fishing spot and time. In other words, there is a need for a device that can visually display the tidal conditions of various locations in a very short period of time.

By the way, according to the harmonic decomposition method, the tide level is expressed as the sum of polynomials of trigonometric functions with time as a variable. The parameters of each position are the phase difference in the function and the coefficient of each term. A feature of this method is that if you calculate the sum from the main terms, it can be approximated with a few terms, and as you increase the number of terms, the accuracy increases. The values announced by government agencies use items 40 to 200. However, it is nearly impossible to calculate polynomials such as 40 to 200 terms with actual small equipment. This is because a large amount of program, memory, and parameter data is required.
Additionally, the error in tides is not something that users are particularly concerned about, nor is it something that is obvious, and it changes depending on the climate.

In the present invention, from the above points, items 4 to 8 are adopted. The formula for calculating the tidal level is described in detail in specialized books on tidal science, so here we will explain it while converting the formula for display devices.

First, the main cause of tides is celestial phenomena, and the following four types of periodic values are important. S: average ecliptic longitude of the moon, h: average ecliptic longitude of the sun, p: average ecliptic longitude of the moon's perigee, N: average ecliptic longitude of the ascending node of the moon. Both are degrees of longitude and take values from 0° to 360°. They have the following values at midnight on January 1, 1900 (24 hour system) Greenwich Mean Time (GMT).

S=277.025゜=So h=280.190゜=ho p=334.385゜=po N=259.157゜=No The number Y of one year (365 days) from this era,
With the remaining number of days (including cumulative leap days) D,
Regarding GNT0 o'clock on any day, it is as follows.

S=So+129.38481°Y+13.17640°D h=ho−0.23872°Y+0.98565°D p=po+40.66249°Y+0.11140°D N=No+19.32818°Y−0.05295°D Each term of tide level minutes The four main divisions of the tide are: M _2nd tide: main lunar semidiurnal tide,
S ₂ : Main solar semidiurnal tide, O ₁ minute tide: Main lunar diurnal tide,
K ₁ minute tide: Sun-moon composite diurnal cycle. Arguments u, f and the harmonic constant H (half tidal difference,
Units are usually cm), K (retarded angle, units are degrees) and east longitude E
Using , each division tide is expressed by the following formula.

M ₂ = H(M ₂ )・f(M ₂ )×cos {−2S+2h+ u(M ₂ )+28.9841042゜t+2E−K(M ₂ )} S ₂ = H(S ₂ )・f(S ₂ )・cos {30゜t +u(S ₂ )+2E−K(S ₂ )} K ₁ = H(K ₁ )・f(K ₁ )・cos{h+90゜+u(K ₁ ) +15.0410686゜t+E−K (K ₁ )} O ₁ = H(O ₁ )・f(O ₁ )・cos {−2S+h+u(O ₁ ) +13.9430356゜t+E−K(O ₁ )} However, t is GMT time (unit, time ), and each u and f are expressed by the following formula.

f(M ₂ )=1.0004−0.0373cosN+0.0002cos2N f(S ₂ )=1 f(K ₁ )=1.006+0.115cosN +−0.0088cos2N+0.0006cos3N f(O ₁ )=1.0089+0.1871cosN −0.0147cos2 N＋0.0014cos3N u(M ₂ )=−2.14°sinN u(S ₂ )=0 u(K ₁ )=−8.86°sinN+0.68°sin2N −0.07°sin3N u(O ₁ )=10.8°sinN−1.34sin2N +0.19sin3N You can find the values of H and K by looking at the ``Tide Level Table, 1982 Edition'' released by the Japan Meteorological Agency. For example, the values for Tokyo Harumi are H (M ² ) = 49.07 cm, H (S ₂ ) = 24.12 cm, H (K ₁ ) =
25.22cm, H (O ₁ ) = 19.65cm, K (M ₂ ) = 153.37°,
K(S ₂ )=182.15°, K(K ₁ )=178.51°, K(O ₁ )=
It is 160.29°. The tidal level difference H from the average tidal level can be obtained from the above formula. That is, H=M ₂ +S ₂ +K ₁
+O ₁ .

The above-mentioned formula has disadvantages when applied to small devices as it is. For example, the era is
The year 1900 is so different from today that calculating the number of years or days becomes complicated. Also, GNT time is inconvenient when used in Japan. Calculating the number of days including leap days becomes complicated. Therefore, perform the following conversion.

First, let us assume that the day following the most recent leap day is epoch time. The date of March 1, 1980 is adopted as an example. Also, convert GMT:t to Japan time J. t=J-
9 (time), and the product of the coefficient of time and (-9) is incorporated into the constant term of the phase of each partial tide. Regarding N, changes of less than one day are so small that they can be ignored, so they are not considered. Therefore, assuming 0:00 a.m. on March 1, 1980 (Japan time), we obtain the following value. Add the subscript I to the symbol. Furthermore, subscripts 1 and 2 of M ₂ , S ₂ , K ₁ , and O ₁ are omitted below. Z indicates a phase expression.

N _I ＝148.71955゜ Z(M) _I ＝119.5682゜ Z(S) _I ＝90゜ Z(K) _I ＝293.58913゜ Z(O) _I ＝185.98642゜ Next, assume that the number of days data is entered in the year, month, and day. Consider leap days and the size of the moon, and reduce the number of multiplications so that accuracy does not deteriorate. The number of years is the same as 1980, and January and February are the months of the previous year, so let's say they are 13th and 14th. In this way, the last day of February becomes the last day of the year, and leap days within the year are no longer considered. The number of years obtained in this way
Separate into 20-year number Ya (7305 days), 4-year number Yb (1461 days), and 1-year number Yc (365 days). That is, the number of years = Ya + Yb + Yc. Ya and Yb include leap days, so leap day calculations are not shown in the table.

Earlier, the month names were March, April... December, March, and 14, but to make it easier to calculate, we subtracted 3 and changed the number of months to 0,
1,...10, 11. Arranging the number of days in the month in order: 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
31, 28 (29), which is five months from the beginning, and if you divide it between the usual July and August, it will be a repetition of large, small, large, small and large. Therefore, the number of months is 5 months.
It is convenient to divide it into Ma (153 days worth) and Mb per month (30 days worth). That is, the number of months = Ma + Mb. Mb takes values from 0 to 4, but when Mb = 1 or 2, it is necessary to add one day of the major month, and when Mb = 3 or 4, it is necessary to add two days of the major month. this
Let D _M = (=0, 1, 2). Normal date is 1
It starts from the day, but for calculation purposes, subtract 1,
Count from day 0, make it the number of days, then add _DM , 6
Separate it into the number of days Da and the number of days Db.

Furthermore, since the east longitude E and the retard angle K of each place are constants specific to each other, they are combined and the data is converted as follows.

X _M = 2E-K (M ₂ ) X _S = 2E-K (S ₂ ) X _K = E-K (K ₁ ) X _O = E-K (O ₁ ) Using the above years and months, N The calculation formula and the calculation formula Z for the phase of the partial tide excluding the time term can be found as follows.

N=N _I +333.17165°Ya +282.63433°Yb +340.67182°Yc +351.8987°Ma +358.4115°Mb +359.6823°Da +359.9471°Db Z (M) = Z (M ) _I +X _M +u(M) +93.1509°Ya +18.630°Yb +100.7529°Yc +229.6305°Ma +348.5550°Mb +213.7110°Da +335.6185°Db Z(S)=Z(S) _I ＋X _S ＋90゜Z(K)＝Z(K) _I ＋X _K ＋u(K) ＋0.15385゜Ya ＋0.03077゜Ya ＋359.76128゜Yc ＋150.80445゜Ma ＋29.5695゜Mb ＋5.9139゜Da +0.98565°Db Z(O)=Z(O) _I +X _O +u(O) +92.99825°Ya +18.59965°Yb +100.9917°Yc +78.82605°Ma +318.9855°Mb +207.7971゜Since the phase is Da + 334.63285°Db, it is calculated by adding or subtracting 360° as appropriate. Except for the term u, all are expressed as sums of positive numbers.

These values, Z _I , X, and each coefficient are converted into numerical values so that they can be easily processed by the CPU. It depends on how much calculation precision is required and which CPU system to use, but in principle it is done as follows.
Make the upper limit of batch data processing compatible with 360°. For 8 bits, 2 ⁸ = 256, for 12 bits, 2 ¹² =
If 4096 is 16 bits, 2 ¹⁶ = 65536 corresponds to 360 degrees. For example, with 16 bits
If you express 119.5682°, it is hexadecimal (hexadecimal)
The display shows 5507H. By doing this, addition for each data can be processed without considering carry-out or the upper limit of the numerical range. This is because subtraction every 360 degrees is automatically processed. The phase value obtained in this way is
Obtain the function value by subtracting the sin or cos table. Alternatively, it is possible to change it to a radian value and find it by series expansion. Multiply this by f and h, and then add the sum to obtain the desired tide level.

To obtain the tide level for each hour, it is sufficient to add the time term to the phase value. In this case as well, the method described above is applied.

In the quarter tide calculation, the amount of change in u or f is small, so even if these are calculated as constants,
It doesn't affect accuracy much. In this case, the processing program can be simplified.

It is also possible to increase the number of divided tides to improve the accuracy of the tide level. In this case, it is recommended to add the next quarter tide. N _2- minute tide: Main lunar elliptic semidiurnal tide, K _2- minute tide: Sun-moon composite semidiurnal tide, Q _1- minute tide: Main lunar elliptic diurnal tide, P _1- minute tide: Main solar diurnal tide. . These formulas are detailed in the manual, so their explanation will be omitted. Also, the harmonic constants H and K of each region corresponding to these are published as data, as in the case of the previous four tides. The added four-quarter tide calculation can also be converted into a calculation formula for small devices by the above-mentioned procedure, so no special changes are required to the program. however,
The data for H and K will double, and the coefficient for years, months, and days will also increase slightly.

FIG. 1 is a flow chart of the calculation procedure described above based on the four-part tide. 1
This is an example in which one day's worth of calculations is performed by repeating calculations hourly.

FIG. 2 is a block diagram of the circuit configuration of the present invention. This configuration itself is well known, and the CPU and
The basic components are RAM, ROM, key switch, and display device.

FIG. 3 is a schematic diagram of an embodiment of the tidal display device of the present invention. The entire surface of the upper display body 31 is made up of dot matrix pixels. In this embodiment, 16 horizontal rows and 24 vertical columns are set. A horizontal line 32 printed in the center indicates the average tide level. Scales 33 printed around the top and bottom of the display 31 indicate the time of the set date, and are marked every six hours. A bar graph displayed above the horizontal line 32 indicates a high tide of that level, and a bar graph displayed below the horizontal line 32 indicates a low tide of that level. Up to 8 levels can be displayed on both the upper and lower sides. The characteristics of this tidal expression method are as follows:
Changes in the tide level over a relatively long period of time, such as one day, can be clearly seen at a glance, the degree of ebb and flow can be quantitatively recognized, and it is easy to judge whether it is a high tide or a low tide. Furthermore, even if the calculations are rough, it is possible to obtain reasonably satisfactory tidal information.

The lower display body 34 in FIG. 3 is for displaying the setting date and setting location. The map of Japan 35 is a printed pattern, and there are several dozen pixels at positions corresponding to ports around the archipelago, and Tokyo Harumi Port 36 is displayed in the figure. The number display pixel 37 displays the year, month, and day, and the figure shows March 1, 1982. The switch 38 is used to select the content of correction; for example, each time the switch is pressed, the selection is made as follows: day -> month -> year -> port. The switch 39 is used to change the correction content, and each time the switch is pressed, the date,
The month, year, or port changes sequentially. Performing tidal calculations each time during correction would waste calculation time, so calculations should only be performed once the desired setting conditions are finalized. For example, the calculation may be started by pressing the switch 39 while pressing the switch 38.

Since the present invention is aimed at small-sized equipment, it is reasonable to use a liquid crystal display device with low current consumption as the display device. However, in consideration of use in dark fishing areas, light-emitting display devices (LEDs and fluorescent display tubes) are used.
It would also be a good idea to adopt A lamp may be added to the liquid crystal display device.

FIG. 4 shows the electrode configuration of the entire dot matrix portion of the liquid crystal display for graphical display. The dotted line pattern is for the common side, and there are 16 lines, and the solid line pattern is for the segment side, and there are 24 lines. To drive this, a voltage averaging method with a 1/16 duty ratio may be used. The common electrode signal has a regular waveform with a constant period, but the segment electrode signal requires serially outputting 16 types of image information periodically. Image information resulting from calculations is usually stored all at once in a buffer memory in RAM. In an 8-bit CPU, it is naturally advantageous to use buffer memory in 8-bit units, and this number of pixels requires 16 x 24 ÷ 8 = 48 8 bits, or 48 bytes of memory.
The correspondence between memory addresses and image positions can vary depending on the output method to the port and the configuration of the driver. In this embodiment, the process is as follows. Divide the screen into two parts above and below the center horizontal line position, divide it into 8 lines each, and divide 1 byte into 8 lines from the top leftmost column.
Collect 24 bytes, then 1 in order from the leftmost column of the bottom row.
The bytes are divided into 48 bytes in total. The correspondence between bit numbers within one byte and pixels is divided into 8 bits and 8 pixels in order from the lower bit to the upper pixel.

Next, convert the tide position into image information for graphs,
Subroutine GRAPH stored in buffer memory
present. Expressed using Z80-based mnemonics. It is assumed that the tide level value is stored in 24 bytes every hour from 0:00 to 23:00 at the address VTIDE. At this time, in each byte storing the tidal level value, the most significant bit is code information of plus (0) and minus (1), and the lower 7 bits are absolute value information of the tidal level difference. The absolute value is standardized to a maximum of 7FH. The starting address of the buffer memory is
GADRS.

GRAPH: LD IY, GADRS LD IY, VTIDE LD B, 24 GRAPH: LD A, [IX+0] AND 70H RRCA RRCA RRCA RRCA INC A LD DE, 0 BIT 7, [IX+0] JR NZ, LOWER HIGHER: SCF RR D DEC A JR NZ, HIGHER GRAPH3: LD [IY+0], D LD [IY+24], E INC IY INC IX DJNZ GRAPH2 RET LOWER: SCF RL E DEC A JR NZ, LOWER JR GRAPH3 End of subroutine The display results of the embodiment of this invention are shown below. It is shown in Figure 5. In addition, the forecast results from the 1981 tide level table published by the Japan Meteorological Agency are attached to the right side of each figure. a is the same 3 as in Figure 3
The first day of the month is Harumi, Tokyo. b is Hiroshima on May 15th, c is Naha on September 23rd, and d is Otaru on December 10th. Everything fits well.

As described above, the tidal display device of the present invention provides the basic configuration, calculation method, and display method on the assumption that it is a small device, and the embodiments have also been found to be satisfactory. Since it is a small device, it is very convenient to have a built-in clock function or to make it into a wristwatch, so it has a wide range of applications.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing a tide level calculation procedure according to an embodiment of the present invention. FIG. 2 is a block diagram of a circuit configuration according to an embodiment of the present invention. FIG. 3 is a schematic diagram of an embodiment of the present invention. 31... Upper display body, 32... Center line, 33...
... Scale, 34 ... Lower display, 35 ... Map of Japan, 36 ... Tokyo Harumi Port, 37 ... Date, 3
8, 39...Switch FIG. 4 shows the electrode configuration of the dot matrix portion of the display. FIG. 5 shows an example of the display results of the embodiment of the present invention and the officially announced ebb and flow times.

Claims (1)

[Claims] 1. A small electronic device for tide display comprising a control circuit section including a CPU, RAM, ROM, etc., a driver, and a display section, wherein the control circuit section uses time as a variable. We use the harmonic decomposition method to calculate the tide level from the sum of polynomials of trigonometric functions, and when we assign a phase angle of 360° to the maximum unit bit number as the phase angle that is the argument of the trigonometric function, we calculate the excess of 360° or more. Means for calculating the tide level using a value obtained by numerically converting the phase angle into a digital value by a calculation program, and outputting a digital signal for display to the driver based on the tide level obtained by the harmonic decomposition method. means for tidal display, wherein the driver drives the display unit based on the digital signal, and the display unit is a dot matrix display device capable of displaying the tide level as a continuous digital bar graph. small electronic devices.