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Попробую объяснить с калькулятором. Начинаем плясать от экватора, т.к. широта там равняется 0. Длина окружности экватора принимается равной 40000 км.Вычислим, какое расстояние содержит 1' на экваторе. 1'=40 000 000м / 360° / 60'= 1852м. Знакомая цифра. Если напрячь мозг, то мы вспоминаем, что это 1 миля. Теперь узнаем сколько метров в 1". 1"=1852м/60"=31м., но это на экваторе, а мы находимся примерно на широте 52°. Из курса воздушной навигации мы знаем, что число метров в секунде прямо пропорционально косинусу угла (на экваторе cos=1, т.к. угол =0, а к полюсу параллели сжимаются). Теперь с помощью калькулятора легко вычислить количество метров в минуте на интересующей нас широте. 1"=31м*cos 52°=19м. Остаётся только отмерить азимут от севера. (истинного, магнитного или компасного.)
я в Ahye.... надо к тебе на курсы записаться
<!-- Copyright 1997-1998 by Charles L. Taylor --><SCRIPT TYPE="text/javascript"><!--var pi = 3.14159265358979;/* Ellipsoid model constants (actual values here are for WGS84) */var sm_a = 6378137.0;var sm_b = 6356752.314;var sm_EccSquared = 6.69437999013e-03;var UTMScaleFactor = 0.9996;/** DegToRad** Converts degrees to radians.**/function DegToRad (deg){return (deg / 180.0 * pi)}/** RadToDeg** Converts radians to degrees.**/function RadToDeg (rad){return (rad / pi * 180.0)}/** ArcLengthOfMeridian** Computes the ellipsoidal distance from the equator to a point at a* given latitude.** Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,* GPS: Theory and Practice, 3rd ed. New York: Springer-Verlag Wien, 1994.** Inputs:* phi - Latitude of the point, in radians.** Globals:* sm_a - Ellipsoid model major axis.* sm_b - Ellipsoid model minor axis.** Returns:* The ellipsoidal distance of the point from the equator, in meters.**/function ArcLengthOfMeridian (phi){var alpha, beta, gamma, delta, epsilon, n;var result;/* Precalculate n */n = (sm_a - sm_b) / (sm_a sm_b);/* Precalculate alpha */alpha = ((sm_a sm_b) / 2.0)* (1.0 (Math.pow (n, 2.0) / 4.0) (Math.pow (n, 4.0) / 64.0));/* Precalculate beta */beta = (-3.0 * n / 2.0) (9.0 * Math.pow (n, 3.0) / 16.0) (-3.0 * Math.pow (n, 5.0) / 32.0);/* Precalculate gamma */gamma = (15.0 * Math.pow (n, 2.0) / 16.0) (-15.0 * Math.pow (n, 4.0) / 32.0);/* Precalculate delta */delta = (-35.0 * Math.pow (n, 3.0) / 48.0) (105.0 * Math.pow (n, 5.0) / 256.0);/* Precalculate epsilon */epsilon = (315.0 * Math.pow (n, 4.0) / 512.0);/* Now calculate the sum of the series and return */result = alpha* (phi (beta * Math.sin (2.0 * phi)) (gamma * Math.sin (4.0 * phi)) (delta * Math.sin (6.0 * phi)) (epsilon * Math.sin (8.0 * phi)));return result;}/** UTMCentralMeridian** Determines the central meridian for the given UTM zone.** Inputs:* zone - An integer value designating the UTM zone, range [1,60].** Returns:* The central meridian for the given UTM zone, in radians, or zero* if the UTM zone parameter is outside the range [1,60].* Range of the central meridian is the radian equivalent of [-177, 177].**/function UTMCentralMeridian (zone){var cmeridian;cmeridian = DegToRad (-183.0 (zone * 6.0));return cmeridian;}/** FootpointLatitude** Computes the footpoint latitude for use in converting transverse* Mercator coordinates to ellipsoidal coordinates.** Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,* GPS: Theory and Practice, 3rd ed. New York: Springer-Verlag Wien, 1994.** Inputs:* y - The UTM northing coordinate, in meters.** Returns:* The footpoint latitude, in radians.**/function FootpointLatitude (y){var y_, alpha_, beta_, gamma_, delta_, epsilon_, n;var result;/* Precalculate n (Eq. 10.18) */n = (sm_a - sm_b) / (sm_a sm_b);/* Precalculate alpha_ (Eq. 10.22) *//* (Same as alpha in Eq. 10.17) */alpha_ = ((sm_a sm_b) / 2.0)* (1 (Math.pow (n, 2.0) / 4) (Math.pow (n, 4.0) / 64));/* Precalculate y_ (Eq. 10.23) */y_ = y / alpha_;/* Precalculate beta_ (Eq. 10.22) */beta_ = (3.0 * n / 2.0) (-27.0 * Math.pow (n, 3.0) / 32.0) (269.0 * Math.pow (n, 5.0) / 512.0);/* Precalculate gamma_ (Eq. 10.22) */gamma_ = (21.0 * Math.pow (n, 2.0) / 16.0) (-55.0 * Math.pow (n, 4.0) / 32.0);/* Precalculate delta_ (Eq. 10.22) */delta_ = (151.0 * Math.pow (n, 3.0) / 96.0) (-417.0 * Math.pow (n, 5.0) / 128.0);/* Precalculate epsilon_ (Eq. 10.22) */epsilon_ = (1097.0 * Math.pow (n, 4.0) / 512.0);/* Now calculate the sum of the series (Eq. 10.21) */result = y_ (beta_ * Math.sin (2.0 * y_)) (gamma_ * Math.sin (4.0 * y_)) (delta_ * Math.sin (6.0 * y_)) (epsilon_ * Math.sin (8.0 * y_));return result;}/** MapLatLonToXY** Converts a latitude/longitude pair to x and y coordinates in the* Transverse Mercator projection. Note that Transverse Mercator is not* the same as UTM; a scale factor is required to convert between them.** Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,* GPS: Theory and Practice, 3rd ed. New York: Springer-Verlag Wien, 1994.** Inputs:* phi - Latitude of the point, in radians.* lambda - Longitude of the point, in radians.* lambda0 - Longitude of the central meridian to be used, in radians.** Outputs:* xy - A 2-element array containing the x and y coordinates* of the computed point.** Returns:* The function does not return a value.**/function MapLatLonToXY (phi, lambda, lambda0, xy){var N, nu2, ep2, t, t2, l;var l3coef, l4coef, l5coef, l6coef, l7coef, l8coef;var tmp;/* Precalculate ep2 */ep2 = (Math.pow (sm_a, 2.0) - Math.pow (sm_b, 2.0)) / Math.pow (sm_b, 2.0);/* Precalculate nu2 */nu2 = ep2 * Math.pow (Math.cos (phi), 2.0);/* Precalculate N */N = Math.pow (sm_a, 2.0) / (sm_b * Math.sqrt (1 nu2));/* Precalculate t */t = Math.tan (phi);t2 = t * t;tmp = (t2 * t2 * t2) - Math.pow (t, 6.0);/* Precalculate l */l = lambda - lambda0;/* Precalculate coefficients for l**n in the equations belowso a normal human being can read the expressions for eastingand northing-- l**1 and l**2 have coefficients of 1.0 */l3coef = 1.0 - t2 nu2;l4coef = 5.0 - t2 9 * nu2 4.0 * (nu2 * nu2);l5coef = 5.0 - 18.0 * t2 (t2 * t2) 14.0 * nu2- 58.0 * t2 * nu2;l6coef = 61.0 - 58.0 * t2 (t2 * t2) 270.0 * nu2- 330.0 * t2 * nu2;l7coef = 61.0 - 479.0 * t2 179.0 * (t2 * t2) - (t2 * t2 * t2);l8coef = 1385.0 - 3111.0 * t2 543.0 * (t2 * t2) - (t2 * t2 * t2);/* Calculate easting (x) */xy[0] = N * Math.cos (phi) * l (N / 6.0 * Math.pow (Math.cos (phi), 3.0) * l3coef * Math.pow (l, 3.0)) (N / 120.0 * Math.pow (Math.cos (phi), 5.0) * l5coef * Math.pow (l, 5.0)) (N / 5040.0 * Math.pow (Math.cos (phi), 7.0) * l7coef * Math.pow (l, 7.0));/* Calculate northing (y) */xy[1] = ArcLengthOfMeridian (phi) (t / 2.0 * N * Math.pow (Math.cos (phi), 2.0) * Math.pow (l, 2.0)) (t / 24.0 * N * Math.pow (Math.cos (phi), 4.0) * l4coef * Math.pow (l, 4.0)) (t / 720.0 * N * Math.pow (Math.cos (phi), 6.0) * l6coef * Math.pow (l, 6.0)) (t / 40320.0 * N * Math.pow (Math.cos (phi), 8.0) * l8coef * Math.pow (l, 8.0));return;}/** MapXYToLatLon** Converts x and y coordinates in the Transverse Mercator projection to* a latitude/longitude pair. Note that Transverse Mercator is not* the same as UTM; a scale factor is required to convert between them.** Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,* GPS: Theory and Practice, 3rd ed. New York: Springer-Verlag Wien, 1994.** Inputs:* x - The easting of the point, in meters.* y - The northing of the point, in meters.* lambda0 - Longitude of the central meridian to be used, in radians.** Outputs:* philambda - A 2-element containing the latitude and longitude* in radians.** Returns:* The function does not return a value.** Remarks:* The local variables Nf, nuf2, tf, and tf2 serve the same purpose as* N, nu2, t, and t2 in MapLatLonToXY, but they are computed with respect* to the footpoint latitude phif.** x1frac, x2frac, x2poly, x3poly, etc. are to enhance readability and* to optimize computations.**/function MapXYToLatLon (x, y, lambda0, philambda){var phif, Nf, Nfpow, nuf2, ep2, tf, tf2, tf4, cf;var x1frac, x2frac, x3frac, x4frac, x5frac, x6frac, x7frac, x8frac;var x2poly, x3poly, x4poly, x5poly, x6poly, x7poly, x8poly;/* Get the value of phif, the footpoint latitude. */phif = FootpointLatitude (y);/* Precalculate ep2 */ep2 = (Math.pow (sm_a, 2.0) - Math.pow (sm_b, 2.0))/ Math.pow (sm_b, 2.0);/* Precalculate cos (phif) */cf = Math.cos (phif);/* Precalculate nuf2 */nuf2 = ep2 * Math.pow (cf, 2.0);/* Precalculate Nf and initialize Nfpow */Nf = Math.pow (sm_a, 2.0) / (sm_b * Math.sqrt (1 nuf2));Nfpow = Nf;/* Precalculate tf */tf = Math.tan (phif);tf2 = tf * tf;tf4 = tf2 * tf2;/* Precalculate fractional coefficients for x**n in the equationsbelow to simplify the expressions for latitude and longitude. */x1frac = 1.0 / (Nfpow * cf);Nfpow *= Nf; /* now equals Nf**2) */x2frac = tf / (2.0 * Nfpow);Nfpow *= Nf; /* now equals Nf**3) */x3frac = 1.0 / (6.0 * Nfpow * cf);Nfpow *= Nf; /* now equals Nf**4) */x4frac = tf / (24.0 * Nfpow);Nfpow *= Nf; /* now equals Nf**5) */x5frac = 1.0 / (120.0 * Nfpow * cf);Nfpow *= Nf; /* now equals Nf**6) */x6frac = tf / (720.0 * Nfpow);Nfpow *= Nf; /* now equals Nf**7) */x7frac = 1.0 / (5040.0 * Nfpow * cf);Nfpow *= Nf; /* now equals Nf**8) */x8frac = tf / (40320.0 * Nfpow);/* Precalculate polynomial coefficients for x**n.-- x**1 does not have a polynomial coefficient. */x2poly = -1.0 - nuf2;x3poly = -1.0 - 2 * tf2 - nuf2;x4poly = 5.0 3.0 * tf2 6.0 * nuf2 - 6.0 * tf2 * nuf2- 3.0 * (nuf2 *nuf2) - 9.0 * tf2 * (nuf2 * nuf2);x5poly = 5.0 28.0 * tf2 24.0 * tf4 6.0 * nuf2 8.0 * tf2 * nuf2;x6poly = -61.0 - 90.0 * tf2 - 45.0 * tf4 - 107.0 * nuf2 162.0 * tf2 * nuf2;x7poly = -61.0 - 662.0 * tf2 - 1320.0 * tf4 - 720.0 * (tf4 * tf2);x8poly = 1385.0 3633.0 * tf2 4095.0 * tf4 1575 * (tf4 * tf2);/* Calculate latitude */philambda[0] = phif x2frac * x2poly * (x * x) x4frac * x4poly * Math.pow (x, 4.0) x6frac * x6poly * Math.pow (x, 6.0) x8frac * x8poly * Math.pow (x, 8.0);/* Calculate longitude */philambda[1] = lambda0 x1frac * x x3frac * x3poly * Math.pow (x, 3.0) x5frac * x5poly * Math.pow (x, 5.0) x7frac * x7poly * Math.pow (x, 7.0);return;}/** LatLonToUTMXY** Converts a latitude/longitude pair to x and y coordinates in the* Universal Transverse Mercator projection.** Inputs:* lat - Latitude of the point, in radians.* lon - Longitude of the point, in radians.* zone - UTM zone to be used for calculating values for x and y.* If zone is less than 1 or greater than 60, the routine* will determine the appropriate zone from the value of lon.** Outputs:* xy - A 2-element array where the UTM x and y values will be stored.** Returns:* The UTM zone used for calculating the values of x and y.**/function LatLonToUTMXY (lat, lon, zone, xy){MapLatLonToXY (lat, lon, UTMCentralMeridian (zone), xy);/* Adjust easting and northing for UTM system. */xy[0] = xy[0] * UTMScaleFactor 500000.0;xy[1] = xy[1] * UTMScaleFactor;if (xy[1] < 0.0)xy[1] = xy[1] 10000000.0;return zone;}/** UTMXYToLatLon** Converts x and y coordinates in the Universal Transverse Mercator* projection to a latitude/longitude pair.** Inputs:* x - The easting of the point, in meters.* y - The northing of the point, in meters.* zone - The UTM zone in which the point lies.* southhemi - True if the point is in the southern hemisphere;* false otherwise.** Outputs:* latlon - A 2-element array containing the latitude and* longitude of the point, in radians.** Returns:* The function does not return a value.**/function UTMXYToLatLon (x, y, zone, southhemi, latlon){var cmeridian;x -= 500000.0;x /= UTMScaleFactor;/* If in southern hemisphere, adjust y accordingly. */if (southhemi)y -= 10000000.0;y /= UTMScaleFactor;cmeridian = UTMCentralMeridian (zone);MapXYToLatLon (x, y, cmeridian, latlon);return;}/** btnToUTM_OnClick** Called when the btnToUTM button is clicked.**/function btnToUTM_OnClick (){var xy = new Array(2);if (isNaN (parseFloat (document.frmConverter.txtLongitude.value))) {alert ("Please enter a valid longitude in the lon field.");return false;}lon = parseFloat (document.frmConverter.txtLongitude.value);if ((lon < -180.0) || (180.0 <= lon)) {alert ("The longitude you entered is out of range. " "Please enter a number in the range [-180, 180).");return false;}if (isNaN (parseFloat (document.frmConverter.txtLatitude.value))) {alert ("Please enter a valid latitude in the lat field.");return false;}lat = parseFloat (document.frmConverter.txtLatitude.value);if ((lat < -90.0) || (90.0 < lat)) {alert ("The latitude you entered is out of range. " "Please enter a number in the range [-90, 90].");return false;}// Compute the UTM zone.zone = Math.floor ((lon 180.0) / 6) 1;zone = LatLonToUTMXY (DegToRad (lat), DegToRad (lon), zone, xy);/* Set the output controls. */document.frmConverter.txtX.value = xy[0];document.frmConverter.txtY.value = xy[1];document.frmConverter.txtZone.value = zone;if (lat < 0)// Set the S button.document.frmConverter.rbtnHemisphere[1].checked = true;else// Set the N button.document.frmConverter.rbtnHemisphere[0].checked = true;return true;}/** btnToGeographic_OnClick** Called when the btnToGeographic button is clicked.**/function btnToGeographic_OnClick (){latlon = new Array(2);var x, y, zone, southhemi;if (isNaN (parseFloat (document.frmConverter.txtX.value))) {alert ("Please enter a valid easting in the x field.");return false;}x = parseFloat (document.frmConverter.txtX.value);if (isNaN (parseFloat (document.frmConverter.txtY.value))) {alert ("Please enter a valid northing in the y field.");return false;}y = parseFloat (document.frmConverter.txtY.value);if (isNaN (parseInt (document.frmConverter.txtZone.value))) {alert ("Please enter a valid UTM zone in the zone field.");return false;}zone = parseFloat (document.frmConverter.txtZone.value);if ((zone < 1) || (60 < zone)) {alert ("The UTM zone you entered is out of range. " "Please enter a number in the range [1, 60].");return false;}if (document.frmConverter.rbtnHemisphere[1].checked == true)southhemi = true;elsesouthhemi = false;UTMXYToLatLon (x, y, zone, southhemi, latlon);document.frmConverter.txtLongitude.value = RadToDeg (latlon[1]);document.frmConverter.txtLatitude.value = RadToDeg (latlon[0]);return true;}// --></SCRIPT>
Вот нашел...погрешность при перегоне координат получилась не больше 2 метров!Код: [Выделить]<!-- Copyright 1997-1998 by Charles L. Taylor --><SCRIPT TYPE="text/javascript"><!--var pi = 3.14159265358979;/* Ellipsoid model constants (actual values here are for WGS84) */var sm_a = 6378137.0;var sm_b = 6356752.314;var sm_EccSquared = 6.69437999013e-03;var UTMScaleFactor = 0.9996;/** DegToRad** Converts degrees to radians.**/function DegToRad (deg){return (deg / 180.0 * pi)}/** RadToDeg** Converts radians to degrees.**/function RadToDeg (rad){return (rad / pi * 180.0)}/** ArcLengthOfMeridian** Computes the ellipsoidal distance from the equator to a point at a* given latitude.** Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,* GPS: Theory and Practice, 3rd ed. New York: Springer-Verlag Wien, 1994.** Inputs:* phi - Latitude of the point, in radians.** Globals:* sm_a - Ellipsoid model major axis.* sm_b - Ellipsoid model minor axis.** Returns:* The ellipsoidal distance of the point from the equator, in meters.**/function ArcLengthOfMeridian (phi){var alpha, beta, gamma, delta, epsilon, n;var result;/* Precalculate n */n = (sm_a - sm_b) / (sm_a sm_b);/* Precalculate alpha */alpha = ((sm_a sm_b) / 2.0)* (1.0 (Math.pow (n, 2.0) / 4.0) (Math.pow (n, 4.0) / 64.0));/* Precalculate beta */beta = (-3.0 * n / 2.0) (9.0 * Math.pow (n, 3.0) / 16.0) (-3.0 * Math.pow (n, 5.0) / 32.0);/* Precalculate gamma */gamma = (15.0 * Math.pow (n, 2.0) / 16.0) (-15.0 * Math.pow (n, 4.0) / 32.0);/* Precalculate delta */delta = (-35.0 * Math.pow (n, 3.0) / 48.0) (105.0 * Math.pow (n, 5.0) / 256.0);/* Precalculate epsilon */epsilon = (315.0 * Math.pow (n, 4.0) / 512.0);/* Now calculate the sum of the series and return */result = alpha* (phi (beta * Math.sin (2.0 * phi)) (gamma * Math.sin (4.0 * phi)) (delta * Math.sin (6.0 * phi)) (epsilon * Math.sin (8.0 * phi)));return result;}/** UTMCentralMeridian** Determines the central meridian for the given UTM zone.** Inputs:* zone - An integer value designating the UTM zone, range [1,60].** Returns:* The central meridian for the given UTM zone, in radians, or zero* if the UTM zone parameter is outside the range [1,60].* Range of the central meridian is the radian equivalent of [-177, 177].**/function UTMCentralMeridian (zone){var cmeridian;cmeridian = DegToRad (-183.0 (zone * 6.0));return cmeridian;}/** FootpointLatitude** Computes the footpoint latitude for use in converting transverse* Mercator coordinates to ellipsoidal coordinates.** Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,* GPS: Theory and Practice, 3rd ed. New York: Springer-Verlag Wien, 1994.** Inputs:* y - The UTM northing coordinate, in meters.** Returns:* The footpoint latitude, in radians.**/function FootpointLatitude (y){var y_, alpha_, beta_, gamma_, delta_, epsilon_, n;var result;/* Precalculate n (Eq. 10.18) */n = (sm_a - sm_b) / (sm_a sm_b);/* Precalculate alpha_ (Eq. 10.22) *//* (Same as alpha in Eq. 10.17) */alpha_ = ((sm_a sm_b) / 2.0)* (1 (Math.pow (n, 2.0) / 4) (Math.pow (n, 4.0) / 64));/* Precalculate y_ (Eq. 10.23) */y_ = y / alpha_;/* Precalculate beta_ (Eq. 10.22) */beta_ = (3.0 * n / 2.0) (-27.0 * Math.pow (n, 3.0) / 32.0) (269.0 * Math.pow (n, 5.0) / 512.0);/* Precalculate gamma_ (Eq. 10.22) */gamma_ = (21.0 * Math.pow (n, 2.0) / 16.0) (-55.0 * Math.pow (n, 4.0) / 32.0);/* Precalculate delta_ (Eq. 10.22) */delta_ = (151.0 * Math.pow (n, 3.0) / 96.0) (-417.0 * Math.pow (n, 5.0) / 128.0);/* Precalculate epsilon_ (Eq. 10.22) */epsilon_ = (1097.0 * Math.pow (n, 4.0) / 512.0);/* Now calculate the sum of the series (Eq. 10.21) */result = y_ (beta_ * Math.sin (2.0 * y_)) (gamma_ * Math.sin (4.0 * y_)) (delta_ * Math.sin (6.0 * y_)) (epsilon_ * Math.sin (8.0 * y_));return result;}/** MapLatLonToXY** Converts a latitude/longitude pair to x and y coordinates in the* Transverse Mercator projection. Note that Transverse Mercator is not* the same as UTM; a scale factor is required to convert between them.** Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,* GPS: Theory and Practice, 3rd ed. New York: Springer-Verlag Wien, 1994.** Inputs:* phi - Latitude of the point, in radians.* lambda - Longitude of the point, in radians.* lambda0 - Longitude of the central meridian to be used, in radians.** Outputs:* xy - A 2-element array containing the x and y coordinates* of the computed point.** Returns:* The function does not return a value.**/function MapLatLonToXY (phi, lambda, lambda0, xy){var N, nu2, ep2, t, t2, l;var l3coef, l4coef, l5coef, l6coef, l7coef, l8coef;var tmp;/* Precalculate ep2 */ep2 = (Math.pow (sm_a, 2.0) - Math.pow (sm_b, 2.0)) / Math.pow (sm_b, 2.0);/* Precalculate nu2 */nu2 = ep2 * Math.pow (Math.cos (phi), 2.0);/* Precalculate N */N = Math.pow (sm_a, 2.0) / (sm_b * Math.sqrt (1 nu2));/* Precalculate t */t = Math.tan (phi);t2 = t * t;tmp = (t2 * t2 * t2) - Math.pow (t, 6.0);/* Precalculate l */l = lambda - lambda0;/* Precalculate coefficients for l**n in the equations belowso a normal human being can read the expressions for eastingand northing-- l**1 and l**2 have coefficients of 1.0 */l3coef = 1.0 - t2 nu2;l4coef = 5.0 - t2 9 * nu2 4.0 * (nu2 * nu2);l5coef = 5.0 - 18.0 * t2 (t2 * t2) 14.0 * nu2- 58.0 * t2 * nu2;l6coef = 61.0 - 58.0 * t2 (t2 * t2) 270.0 * nu2- 330.0 * t2 * nu2;l7coef = 61.0 - 479.0 * t2 179.0 * (t2 * t2) - (t2 * t2 * t2);l8coef = 1385.0 - 3111.0 * t2 543.0 * (t2 * t2) - (t2 * t2 * t2);/* Calculate easting (x) */xy[0] = N * Math.cos (phi) * l (N / 6.0 * Math.pow (Math.cos (phi), 3.0) * l3coef * Math.pow (l, 3.0)) (N / 120.0 * Math.pow (Math.cos (phi), 5.0) * l5coef * Math.pow (l, 5.0)) (N / 5040.0 * Math.pow (Math.cos (phi), 7.0) * l7coef * Math.pow (l, 7.0));/* Calculate northing (y) */xy[1] = ArcLengthOfMeridian (phi) (t / 2.0 * N * Math.pow (Math.cos (phi), 2.0) * Math.pow (l, 2.0)) (t / 24.0 * N * Math.pow (Math.cos (phi), 4.0) * l4coef * Math.pow (l, 4.0)) (t / 720.0 * N * Math.pow (Math.cos (phi), 6.0) * l6coef * Math.pow (l, 6.0)) (t / 40320.0 * N * Math.pow (Math.cos (phi), 8.0) * l8coef * Math.pow (l, 8.0));return;}/** MapXYToLatLon** Converts x and y coordinates in the Transverse Mercator projection to* a latitude/longitude pair. Note that Transverse Mercator is not* the same as UTM; a scale factor is required to convert between them.** Reference: Hoffmann-Wellenhof, B., Lichtenegger, H., and Collins, J.,* GPS: Theory and Practice, 3rd ed. New York: Springer-Verlag Wien, 1994.** Inputs:* x - The easting of the point, in meters.* y - The northing of the point, in meters.* lambda0 - Longitude of the central meridian to be used, in radians.** Outputs:* philambda - A 2-element containing the latitude and longitude* in radians.** Returns:* The function does not return a value.** Remarks:* The local variables Nf, nuf2, tf, and tf2 serve the same purpose as* N, nu2, t, and t2 in MapLatLonToXY, but they are computed with respect* to the footpoint latitude phif.** x1frac, x2frac, x2poly, x3poly, etc. are to enhance readability and* to optimize computations.**/function MapXYToLatLon (x, y, lambda0, philambda){var phif, Nf, Nfpow, nuf2, ep2, tf, tf2, tf4, cf;var x1frac, x2frac, x3frac, x4frac, x5frac, x6frac, x7frac, x8frac;var x2poly, x3poly, x4poly, x5poly, x6poly, x7poly, x8poly;/* Get the value of phif, the footpoint latitude. */phif = FootpointLatitude (y);/* Precalculate ep2 */ep2 = (Math.pow (sm_a, 2.0) - Math.pow (sm_b, 2.0))/ Math.pow (sm_b, 2.0);/* Precalculate cos (phif) */cf = Math.cos (phif);/* Precalculate nuf2 */nuf2 = ep2 * Math.pow (cf, 2.0);/* Precalculate Nf and initialize Nfpow */Nf = Math.pow (sm_a, 2.0) / (sm_b * Math.sqrt (1 nuf2));Nfpow = Nf;/* Precalculate tf */tf = Math.tan (phif);tf2 = tf * tf;tf4 = tf2 * tf2;/* Precalculate fractional coefficients for x**n in the equationsbelow to simplify the expressions for latitude and longitude. */x1frac = 1.0 / (Nfpow * cf);Nfpow *= Nf; /* now equals Nf**2) */x2frac = tf / (2.0 * Nfpow);Nfpow *= Nf; /* now equals Nf**3) */x3frac = 1.0 / (6.0 * Nfpow * cf);Nfpow *= Nf; /* now equals Nf**4) */x4frac = tf / (24.0 * Nfpow);Nfpow *= Nf; /* now equals Nf**5) */x5frac = 1.0 / (120.0 * Nfpow * cf);Nfpow *= Nf; /* now equals Nf**6) */x6frac = tf / (720.0 * Nfpow);Nfpow *= Nf; /* now equals Nf**7) */x7frac = 1.0 / (5040.0 * Nfpow * cf);Nfpow *= Nf; /* now equals Nf**8) */x8frac = tf / (40320.0 * Nfpow);/* Precalculate polynomial coefficients for x**n.-- x**1 does not have a polynomial coefficient. */x2poly = -1.0 - nuf2;x3poly = -1.0 - 2 * tf2 - nuf2;x4poly = 5.0 3.0 * tf2 6.0 * nuf2 - 6.0 * tf2 * nuf2- 3.0 * (nuf2 *nuf2) - 9.0 * tf2 * (nuf2 * nuf2);x5poly = 5.0 28.0 * tf2 24.0 * tf4 6.0 * nuf2 8.0 * tf2 * nuf2;x6poly = -61.0 - 90.0 * tf2 - 45.0 * tf4 - 107.0 * nuf2 162.0 * tf2 * nuf2;x7poly = -61.0 - 662.0 * tf2 - 1320.0 * tf4 - 720.0 * (tf4 * tf2);x8poly = 1385.0 3633.0 * tf2 4095.0 * tf4 1575 * (tf4 * tf2);/* Calculate latitude */philambda[0] = phif x2frac * x2poly * (x * x) x4frac * x4poly * Math.pow (x, 4.0) x6frac * x6poly * Math.pow (x, 6.0) x8frac * x8poly * Math.pow (x, 8.0);/* Calculate longitude */philambda[1] = lambda0 x1frac * x x3frac * x3poly * Math.pow (x, 3.0) x5frac * x5poly * Math.pow (x, 5.0) x7frac * x7poly * Math.pow (x, 7.0);return;}/** LatLonToUTMXY** Converts a latitude/longitude pair to x and y coordinates in the* Universal Transverse Mercator projection.** Inputs:* lat - Latitude of the point, in radians.* lon - Longitude of the point, in radians.* zone - UTM zone to be used for calculating values for x and y.* If zone is less than 1 or greater than 60, the routine* will determine the appropriate zone from the value of lon.** Outputs:* xy - A 2-element array where the UTM x and y values will be stored.** Returns:* The UTM zone used for calculating the values of x and y.**/function LatLonToUTMXY (lat, lon, zone, xy){MapLatLonToXY (lat, lon, UTMCentralMeridian (zone), xy);/* Adjust easting and northing for UTM system. */xy[0] = xy[0] * UTMScaleFactor 500000.0;xy[1] = xy[1] * UTMScaleFactor;if (xy[1] < 0.0)xy[1] = xy[1] 10000000.0;return zone;}/** UTMXYToLatLon** Converts x and y coordinates in the Universal Transverse Mercator* projection to a latitude/longitude pair.** Inputs:* x - The easting of the point, in meters.* y - The northing of the point, in meters.* zone - The UTM zone in which the point lies.* southhemi - True if the point is in the southern hemisphere;* false otherwise.** Outputs:* latlon - A 2-element array containing the latitude and* longitude of the point, in radians.** Returns:* The function does not return a value.**/function UTMXYToLatLon (x, y, zone, southhemi, latlon){var cmeridian;x -= 500000.0;x /= UTMScaleFactor;/* If in southern hemisphere, adjust y accordingly. */if (southhemi)y -= 10000000.0;y /= UTMScaleFactor;cmeridian = UTMCentralMeridian (zone);MapXYToLatLon (x, y, cmeridian, latlon);return;}/** btnToUTM_OnClick** Called when the btnToUTM button is clicked.**/function btnToUTM_OnClick (){var xy = new Array(2);if (isNaN (parseFloat (document.frmConverter.txtLongitude.value))) {alert ("Please enter a valid longitude in the lon field.");return false;}lon = parseFloat (document.frmConverter.txtLongitude.value);if ((lon < -180.0) || (180.0 <= lon)) {alert ("The longitude you entered is out of range. " "Please enter a number in the range [-180, 180).");return false;}if (isNaN (parseFloat (document.frmConverter.txtLatitude.value))) {alert ("Please enter a valid latitude in the lat field.");return false;}lat = parseFloat (document.frmConverter.txtLatitude.value);if ((lat < -90.0) || (90.0 < lat)) {alert ("The latitude you entered is out of range. " "Please enter a number in the range [-90, 90].");return false;}// Compute the UTM zone.zone = Math.floor ((lon 180.0) / 6) 1;zone = LatLonToUTMXY (DegToRad (lat), DegToRad (lon), zone, xy);/* Set the output controls. */document.frmConverter.txtX.value = xy[0];document.frmConverter.txtY.value = xy[1];document.frmConverter.txtZone.value = zone;if (lat < 0)// Set the S button.document.frmConverter.rbtnHemisphere[1].checked = true;else// Set the N button.document.frmConverter.rbtnHemisphere[0].checked = true;return true;}/** btnToGeographic_OnClick** Called when the btnToGeographic button is clicked.**/function btnToGeographic_OnClick (){latlon = new Array(2);var x, y, zone, southhemi;if (isNaN (parseFloat (document.frmConverter.txtX.value))) {alert ("Please enter a valid easting in the x field.");return false;}x = parseFloat (document.frmConverter.txtX.value);if (isNaN (parseFloat (document.frmConverter.txtY.value))) {alert ("Please enter a valid northing in the y field.");return false;}y = parseFloat (document.frmConverter.txtY.value);if (isNaN (parseInt (document.frmConverter.txtZone.value))) {alert ("Please enter a valid UTM zone in the zone field.");return false;}zone = parseFloat (document.frmConverter.txtZone.value);if ((zone < 1) || (60 < zone)) {alert ("The UTM zone you entered is out of range. " "Please enter a number in the range [1, 60].");return false;}if (document.frmConverter.rbtnHemisphere[1].checked == true)southhemi = true;elsesouthhemi = false;UTMXYToLatLon (x, y, zone, southhemi, latlon);document.frmConverter.txtLongitude.value = RadToDeg (latlon[1]);document.frmConverter.txtLatitude.value = RadToDeg (latlon[0]);return true;}// --></SCRIPT>тему можно считать закрытой