Knowledge (XXG)

Sight reduction

Source 📝

63: 1650: 1227: 79: 1932: 1455: 790: 1734: 522: 1277: 927:
This method is a practical procedure to reduce celestial sights with the needed accuracy, without using electronic tools such as calculator or a computer. And it could serve as a backup in case of malfunction of the positioning system aboard.
914:
H.O. 211 (Dead Reckoning Altitude and Azimuth Table, known as Ageton, 1931, 36pg. And 2 variants of H.O. 211: Compact Sight Reduction Table, also known as Ageton–Bayless, 1980, 9+ pg. S-Table, also known as Pepperday, 1992, 9+
470: 1927:{\displaystyle \operatorname {hav} (Z)={\frac {\operatorname {hav} (90^{\circ }\pm \vert Dec\vert )-\operatorname {hav} (\vert Lat\vert -Hc)}{1-\operatorname {hav} (\vert Lat\vert -Hc)-\operatorname {hav} (\vert Lat\vert +Hc)}}} 1704: 1159: 1003: 1272: 1537: 1450:{\displaystyle \operatorname {hav} (ZD)=\operatorname {hav} (Lat-Dec)+\left(1-\operatorname {hav} (Lat-Dec)-\operatorname {hav} (Lat+Dec)\right)\cdot \operatorname {hav} (LHA)} 317: 1115: 1059: 275: 785:{\displaystyle \cos(Z)={\frac {\sin(Dec)-\sin(Hc)\cdot \sin(Lat)}{\cos(Hc)\cdot \cos(Lat)}}={\frac {\sin(Dec)}{\cos(Hc)\cdot \cos(Lat)}}-\tan(Hc)\cdot \tan(Lat).} 219: 187: 155: 125: 1480: 881: 838: 815: 515: 306: 1724: 858: 492: 1726:
is E↔W as the name of the meridian angle, but the N↕S name is not determined. In most situations azimuth ambiguities are resolved simply by observation.
887:(Marcq St Hilaire method), which uses the difference in observed and calculated altitudes to ascertain one's relative location to the assumed point. 2073:
This computation of the altitude and the azimuth needs a haversine table. For a precision of 1 minute of arc, a four figure table is enough.
2205: 1663: 2407:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
2327: 2257: 2253: 2249: 2245: 2241: 2237: 2445: 2270: 899:
The Nautical Almanac Sight Reduction (NASR, originally known as Concise Tables for Sight Reduction or Davies, 1984, 22pg)
902:
Pub. 249 (formerly H.O. 249, Sight Reduction Tables for Air Navigation, A.P. 3270 in the UK, 1947–53, 1+2 volumes)
905:
Pub. 229 (formerly H.O. 229, Sight Reduction Tables for Marine Navigation, H.D. 605/NP 401 in the UK, 1970, 6 volumes.
2339: 1120: 2363: 2351: 2315: 2180: 1646:
For the azimuth a diagram was developed for a faster solution without calculation, and with an accuracy of 1°.
309: 51: 943: 1248: 908:
The variant of HO-229: Sight Reduction Tables for Small Boat Navigation, known as Schlereth, 1983, 1 volume)
2425: 1491: 2393: 2218: 62: 2269:
Table de point miniature (Hauteur et azimut), by R. Doniol, Navigation IFN Vol. III Nº 10, Avril 1955
1729:
When there are reasons for doubt or for the purpose of checking the following formula should be used:
2175: 1064: 1008: 222: 2440: 2420: 2283: 936:
The first approach of a compact and concise method was published by R. Doniol in 1955 and involved
2399: 230: 54:. The calculation can be done by computer, or by hand via tabular methods and longhand methods. 2226: 2222: 2291: 1649: 911:
H.O. 214 (Tables of Computed Altitude and Azimuth, H.D. 486 in the UK, 1936–46, 9 vol.)
2426:
Vector Solution for the intersection of two Circles of Equal Altitude - free App for android
2185: 884: 278: 37: 33: 2328:
http://fer3.com/arc/m2.aspx/Gregs-article-havDoniol-Ocean-Navigator-HannoIx-jun-2015-g31689
1226: 1483: 918:
H.O. 208 (Navigation Tables for Mariners and Aviators, known as Dreisonstok, 1928, 113pg.)
465:{\displaystyle \sin(Hc)=\sin(Lat)\cdot \sin(Dec)+\cos(Lat)\cdot \cos(Dec)\cdot \cos(LHA).} 17: 198: 166: 134: 104: 1462: 863: 820: 797: 497: 288: 47:, of a celestial body for a line of position; or the data obtained by such observation. 1937: 1709: 1543: 843: 477: 25: 2434: 78: 190: 2340:
http://fer3.com/arc/m2.aspx/Hc-Azimuth-Diagram-finally-HannoIx-aug-2013-g24772
2170: 2295: 2352:
http://fer3.com/arc/m2.aspx/Longhand-Sight-Reduction-Bergman-nov-2014-g29441
2316:
http://fer3.com/arc/m2.aspx/Longhand-Sight-Reduction-HannoIx-nov-2014-g29121
1235: 937: 158: 43:
Sight is defined as the observation of the altitude, and sometimes also the
128: 71: 44: 29: 2415: 2290:(227). Ix, Hanno. Portland, ME, USA: Navigator Publishing LLC: 42–43. 1943:
if same name for latitude and declination (both are North or South)
1549:
if same name for latitude and declination (both are North or South)
2015:= archav() -> inverse look-up at the haversine tables if Latitude 1660:
An ambiguity in the value of azimuth may arise since in the diagram
1245:
A compact expression for the altitude was derived using haversines,
2376: 2410: 1648: 1225: 77: 61: 161:(East - positive, West - negative), both approximate (assumed); 1951:|) if contrary name (one is North the other is South) 1573:|) if contrary name (one is North the other is South) 1699:{\displaystyle 0^{\circ }\leqslant Z\leqslant 90^{\circ }} 517:(Zn=0 at North, measured eastward) is then calculated by: 1657:
This diagram could be used also for star identification.
1636:= archav() -> inverse look-up at the haversine tables 2404: 1239: 794:
These values are contrasted with the observed altitude
1238:
was developed between 2014 and 2015, and published in
1737: 1712: 1666: 1494: 1465: 1280: 1251: 1123: 1067: 1011: 946: 866: 846: 823: 800: 525: 500: 480: 320: 291: 233: 201: 169: 137: 107: 285:First calculate the altitude of the celestial body 1926: 1718: 1698: 1531: 1474: 1449: 1266: 1153: 1109: 1053: 997: 875: 852: 832: 809: 784: 509: 486: 464: 300: 269: 213: 181: 149: 119: 28:(in celestial navigation usually obtained using a 50:The mathematical basis of sight reduction is the 2400:resources for Longhand Haversine Sight Reduction 2364:"NavList: Re: Longhand Sight Reduction (129172)" 2411:Celestial Tools for the USPS/CPS JN/N Student 8: 1906: 1894: 1867: 1855: 1823: 1811: 1793: 1781: 32:) the information needed for establishing a 1234:A practical and friendly method using only 1154:{\displaystyle a=\operatorname {hav} (LHA)} 2350:Azimuth haversine formula by Lars Bergman 1772: 1756: 1736: 1711: 1690: 1671: 1665: 1511: 1493: 1464: 1279: 1250: 1122: 1066: 1010: 945: 865: 845: 822: 799: 663: 544: 524: 499: 479: 319: 290: 232: 200: 168: 136: 106: 2314:Altitude haversine formula by Hanno Ix 2258:Pub. 229 Volume 6. Latitudes 75° to 90° 2254:Pub. 229 Volume 5. Latitudes 60° to 75° 2250:Pub. 229 Volume 4. Latitudes 45° to 60° 2246:Pub. 229 Volume 3. Latitudes 30° to 45° 2242:Pub. 229 Volume 2. Latitudes 15° to 30° 2238:Pub. 229 Volume 1. Latitudes 0° to 15° 2227:Pub. 249 Volume 3. Latitudes 40° to 89° 2197: 998:{\displaystyle \sin(Hc)=n-a\cdot (m+n)} 2421:Sight Reduction - free App for android 2394:AstroNavigation - Free App for Windows 2223:Pub. 249 Volume 2. Latitudes 0° to 39° 1267:{\displaystyle \operatorname {hav} ()} 131:(North - positive, South - negative), 1274:, for all the terms of the equation: 7: 2416:Graphical all-haversine Hc reduction 2145:= archav(0.7979) = 126.6° Because 1532:{\displaystyle Hc=(90^{\circ }-ZD)} 1230:Haversine Sight Reduction algorithm 66:Steps for measuring and correcting 2121:= 90° - 77° 39′ = 12° 21′ Azimuth 923:Longhand haversine sight reduction 24:is the process of deriving from a 14: 2206:The American Practical Navigator 2377:Natural-Haversine 4-place Table 2284:"Ultra compact sight reduction" 1110:{\displaystyle m=\cos(Lat+Dec)} 1054:{\displaystyle n=\cos(Lat-Dec)} 940:. The altitude is derived from 2080: 1942: 1918: 1891: 1879: 1852: 1835: 1808: 1796: 1765: 1750: 1744: 1548: 1526: 1504: 1444: 1432: 1415: 1391: 1379: 1355: 1332: 1308: 1296: 1287: 1261: 1258: 1148: 1136: 1104: 1080: 1048: 1024: 992: 980: 962: 953: 776: 764: 752: 743: 728: 716: 704: 695: 684: 672: 654: 642: 630: 621: 610: 598: 586: 577: 565: 553: 538: 532: 456: 444: 432: 420: 408: 396: 384: 372: 360: 348: 336: 327: 1: 2326:Azimuth diagram by Hanno Ix. 2282:Rudzinski, Greg (July 2015). 2117:= archav(0.3930) = 77° 39′ 1222:Ultra compact sight reduction 1539:is the calculated altitude. 883:are the three inputs to the 1653:Azimuth diagram by Hanno Ix 270:{\displaystyle LHA=GHA+Lon} 2462: 2149:< 180° and Latitude is 895:The methods included are: 2398:Navigational Algorithms: 2392:Navigational Algorithms: 2219:Pub. 249 Volume 1. Stars 2181:Circle of equal altitude 310:circle of equal altitude 52:circle of equal altitude 891:Tabular sight reduction 2338:Hc by Azimuth Diagram 1928: 1720: 1700: 1654: 1533: 1476: 1451: 1268: 1231: 1155: 1111: 1055: 999: 877: 854: 834: 811: 786: 511: 488: 466: 308:using the equation of 302: 271: 215: 183: 151: 121: 95: 75: 2093:= 57° 17.0′ Altitude 1929: 1721: 1701: 1652: 1534: 1477: 1452: 1269: 1229: 1156: 1112: 1056: 1000: 878: 855: 835: 812: 787: 512: 489: 467: 303: 281:of the body observed. 272: 225:of the body observed; 216: 193:of the body observed; 184: 152: 122: 81: 65: 2446:Celestial navigation 2176:Celestial navigation 2089:= 21° 11.0′ S (−) 2085:= 34° 10.0′ N (+) 1735: 1710: 1664: 1492: 1463: 1278: 1249: 1164:The calculation is: 1121: 1065: 1009: 944: 864: 844: 821: 798: 523: 498: 478: 318: 289: 231: 223:Greenwich hour angle 199: 167: 135: 105: 94:in intercept method. 214:{\displaystyle GHA} 182:{\displaystyle Dec} 150:{\displaystyle Lon} 120:{\displaystyle Lat} 1955:= hav(90° + | 1947:= hav(90° − | 1924: 1716: 1696: 1655: 1529: 1475:{\displaystyle ZD} 1472: 1447: 1264: 1232: 1151: 1107: 1051: 995: 876:{\displaystyle Hc} 873: 850: 833:{\displaystyle Ho} 830: 810:{\displaystyle Ho} 807: 782: 510:{\displaystyle Zn} 507: 484: 462: 301:{\displaystyle Hc} 298: 267: 211: 179: 147: 117: 96: 76: 1936:The algorithm if 1922: 1719:{\displaystyle Z} 1542:The algorithm if 853:{\displaystyle Z} 732: 658: 487:{\displaystyle Z} 2453: 2380: 2374: 2368: 2367: 2360: 2354: 2348: 2342: 2336: 2330: 2324: 2318: 2312: 2306: 2305: 2303: 2302: 2279: 2273: 2267: 2261: 2235: 2229: 2216: 2210: 2202: 2186:Intercept method 1978: 1966: 1958: 1950: 1933: 1931: 1930: 1925: 1923: 1921: 1838: 1777: 1776: 1757: 1725: 1723: 1722: 1717: 1705: 1703: 1702: 1697: 1695: 1694: 1676: 1675: 1596: 1592: 1584: 1580: 1572: 1568: 1560: 1556: 1538: 1536: 1535: 1530: 1516: 1515: 1481: 1479: 1478: 1473: 1456: 1454: 1453: 1448: 1422: 1418: 1273: 1271: 1270: 1265: 1160: 1158: 1157: 1152: 1116: 1114: 1113: 1108: 1060: 1058: 1057: 1052: 1004: 1002: 1001: 996: 885:intercept method 882: 880: 879: 874: 859: 857: 856: 851: 839: 837: 836: 831: 816: 814: 813: 808: 791: 789: 788: 783: 733: 731: 687: 664: 659: 657: 613: 545: 516: 514: 513: 508: 493: 491: 490: 485: 471: 469: 468: 463: 307: 305: 304: 299: 279:local hour angle 276: 274: 273: 268: 220: 218: 217: 212: 188: 186: 185: 180: 156: 154: 153: 148: 126: 124: 123: 118: 93: 89: 85: 69: 38:intercept method 34:line of position 2461: 2460: 2456: 2455: 2454: 2452: 2451: 2450: 2431: 2430: 2389: 2384: 2383: 2375: 2371: 2362: 2361: 2357: 2349: 2345: 2337: 2333: 2325: 2321: 2313: 2309: 2300: 2298: 2288:Ocean Navigator 2281: 2280: 2276: 2268: 2264: 2236: 2232: 2217: 2213: 2203: 2199: 2194: 2167: 2162: 2137:= 0.0358 hav( 2109:= 0.2157 hav( 2079: 2071: 1976: 1964: 1956: 1948: 1938:absolute values 1839: 1768: 1758: 1733: 1732: 1708: 1707: 1686: 1667: 1662: 1661: 1644: 1594: 1593:| − | 1590: 1582: 1581:| + | 1578: 1570: 1569:| + | 1566: 1558: 1557:| − | 1554: 1544:absolute values 1507: 1490: 1489: 1484:zenith distance 1461: 1460: 1342: 1338: 1276: 1275: 1247: 1246: 1224: 1219: 1119: 1118: 1063: 1062: 1007: 1006: 942: 941: 934: 925: 893: 862: 861: 842: 841: 819: 818: 796: 795: 688: 665: 614: 546: 521: 520: 496: 495: 476: 475: 316: 315: 287: 286: 229: 228: 197: 196: 165: 164: 133: 132: 103: 102: 91: 87: 83: 67: 60: 36:, generally by 22:sight reduction 18:astronavigation 12: 11: 5: 2459: 2457: 2449: 2448: 2443: 2433: 2432: 2429: 2428: 2423: 2418: 2413: 2408: 2402: 2396: 2388: 2387:External links 2385: 2382: 2381: 2369: 2355: 2343: 2331: 2319: 2307: 2274: 2262: 2230: 2211: 2196: 2195: 2193: 2190: 2189: 2188: 2183: 2178: 2173: 2166: 2163: 2078: 2075: 1920: 1917: 1914: 1911: 1908: 1905: 1902: 1899: 1896: 1893: 1890: 1887: 1884: 1881: 1878: 1875: 1872: 1869: 1866: 1863: 1860: 1857: 1854: 1851: 1848: 1845: 1842: 1837: 1834: 1831: 1828: 1825: 1822: 1819: 1816: 1813: 1810: 1807: 1804: 1801: 1798: 1795: 1792: 1789: 1786: 1783: 1780: 1775: 1771: 1767: 1764: 1761: 1755: 1752: 1749: 1746: 1743: 1740: 1715: 1693: 1689: 1685: 1682: 1679: 1674: 1670: 1528: 1525: 1522: 1519: 1514: 1510: 1506: 1503: 1500: 1497: 1471: 1468: 1446: 1443: 1440: 1437: 1434: 1431: 1428: 1425: 1421: 1417: 1414: 1411: 1408: 1405: 1402: 1399: 1396: 1393: 1390: 1387: 1384: 1381: 1378: 1375: 1372: 1369: 1366: 1363: 1360: 1357: 1354: 1351: 1348: 1345: 1341: 1337: 1334: 1331: 1328: 1325: 1322: 1319: 1316: 1313: 1310: 1307: 1304: 1301: 1298: 1295: 1292: 1289: 1286: 1283: 1263: 1260: 1257: 1254: 1223: 1220: 1166: 1150: 1147: 1144: 1141: 1138: 1135: 1132: 1129: 1126: 1106: 1103: 1100: 1097: 1094: 1091: 1088: 1085: 1082: 1079: 1076: 1073: 1070: 1050: 1047: 1044: 1041: 1038: 1035: 1032: 1029: 1026: 1023: 1020: 1017: 1014: 994: 991: 988: 985: 982: 979: 976: 973: 970: 967: 964: 961: 958: 955: 952: 949: 933: 930: 924: 921: 920: 919: 916: 912: 909: 906: 903: 900: 892: 889: 872: 869: 849: 829: 826: 806: 803: 781: 778: 775: 772: 769: 766: 763: 760: 757: 754: 751: 748: 745: 742: 739: 736: 730: 727: 724: 721: 718: 715: 712: 709: 706: 703: 700: 697: 694: 691: 686: 683: 680: 677: 674: 671: 668: 662: 656: 653: 650: 647: 644: 641: 638: 635: 632: 629: 626: 623: 620: 617: 612: 609: 606: 603: 600: 597: 594: 591: 588: 585: 582: 579: 576: 573: 570: 567: 564: 561: 558: 555: 552: 549: 543: 540: 537: 534: 531: 528: 506: 503: 483: 461: 458: 455: 452: 449: 446: 443: 440: 437: 434: 431: 428: 425: 422: 419: 416: 413: 410: 407: 404: 401: 398: 395: 392: 389: 386: 383: 380: 377: 374: 371: 368: 365: 362: 359: 356: 353: 350: 347: 344: 341: 338: 335: 332: 329: 326: 323: 297: 294: 283: 282: 266: 263: 260: 257: 254: 251: 248: 245: 242: 239: 236: 226: 210: 207: 204: 194: 178: 175: 172: 162: 146: 143: 140: 116: 113: 110: 59: 56: 13: 10: 9: 6: 4: 3: 2: 2458: 2447: 2444: 2442: 2439: 2438: 2436: 2427: 2424: 2422: 2419: 2417: 2414: 2412: 2409: 2406: 2403: 2401: 2397: 2395: 2391: 2390: 2386: 2378: 2373: 2370: 2365: 2359: 2356: 2353: 2347: 2344: 2341: 2335: 2332: 2329: 2323: 2320: 2317: 2311: 2308: 2297: 2293: 2289: 2285: 2278: 2275: 2272: 2266: 2263: 2259: 2255: 2251: 2247: 2243: 2239: 2234: 2231: 2228: 2224: 2220: 2215: 2212: 2208: 2207: 2201: 2198: 2191: 2187: 2184: 2182: 2179: 2177: 2174: 2172: 2169: 2168: 2164: 2160: 2156: 2152: 2148: 2144: 2141:) = 0.7979 2140: 2136: 2132: 2128: 2124: 2120: 2116: 2113:) = 0.3930 2112: 2108: 2104: 2100: 2096: 2092: 2088: 2084: 2076: 2074: 2070: 2066: 2062: 2058: 2054: 2050: 2046: 2042: 2038: 2034: 2030: 2026: 2022: 2018: 2014: 2010: 2006: 2002: 1998: 1994: 1990: 1986: 1982: 1974: 1970: 1962: 1954: 1946: 1941: 1940:are used is: 1939: 1934: 1915: 1912: 1909: 1903: 1900: 1897: 1888: 1885: 1882: 1876: 1873: 1870: 1864: 1861: 1858: 1849: 1846: 1843: 1840: 1832: 1829: 1826: 1820: 1817: 1814: 1805: 1802: 1799: 1790: 1787: 1784: 1778: 1773: 1769: 1762: 1759: 1753: 1747: 1741: 1738: 1730: 1727: 1713: 1691: 1687: 1683: 1680: 1677: 1672: 1668: 1658: 1651: 1647: 1643: 1639: 1635: 1631: 1627: 1623: 1619: 1615: 1611: 1608: 1604: 1600: 1588: 1576: 1564: 1552: 1547: 1546:are used is: 1545: 1540: 1523: 1520: 1517: 1512: 1508: 1501: 1498: 1495: 1487: 1485: 1469: 1466: 1457: 1441: 1438: 1435: 1429: 1426: 1423: 1419: 1412: 1409: 1406: 1403: 1400: 1397: 1394: 1388: 1385: 1382: 1376: 1373: 1370: 1367: 1364: 1361: 1358: 1352: 1349: 1346: 1343: 1339: 1335: 1329: 1326: 1323: 1320: 1317: 1314: 1311: 1305: 1302: 1299: 1293: 1290: 1284: 1281: 1255: 1252: 1243: 1241: 1237: 1228: 1221: 1217: 1213: 1209: 1205: 1201: 1197: 1193: 1189: 1185: 1181: 1177: 1173: 1169: 1165: 1162: 1145: 1142: 1139: 1133: 1130: 1127: 1124: 1101: 1098: 1095: 1092: 1089: 1086: 1083: 1077: 1074: 1071: 1068: 1045: 1042: 1039: 1036: 1033: 1030: 1027: 1021: 1018: 1015: 1012: 989: 986: 983: 977: 974: 971: 968: 965: 959: 956: 950: 947: 939: 931: 929: 922: 917: 913: 910: 907: 904: 901: 898: 897: 896: 890: 888: 886: 870: 867: 847: 827: 824: 804: 801: 792: 779: 773: 770: 767: 761: 758: 755: 749: 746: 740: 737: 734: 725: 722: 719: 713: 710: 707: 701: 698: 692: 689: 681: 678: 675: 669: 666: 660: 651: 648: 645: 639: 636: 633: 627: 624: 618: 615: 607: 604: 601: 595: 592: 589: 583: 580: 574: 571: 568: 562: 559: 556: 550: 547: 541: 535: 529: 526: 518: 504: 501: 481: 472: 459: 453: 450: 447: 441: 438: 435: 429: 426: 423: 417: 414: 411: 405: 402: 399: 393: 390: 387: 381: 378: 375: 369: 366: 363: 357: 354: 351: 345: 342: 339: 333: 330: 324: 321: 313: 311: 295: 292: 280: 264: 261: 258: 255: 252: 249: 246: 243: 240: 237: 234: 227: 224: 208: 205: 202: 195: 192: 176: 173: 170: 163: 160: 144: 141: 138: 130: 114: 111: 108: 101: 100: 99: 80: 73: 64: 57: 55: 53: 48: 46: 41: 39: 35: 31: 27: 23: 19: 2372: 2358: 2346: 2334: 2322: 2310: 2299:. Retrieved 2287: 2277: 2265: 2233: 2214: 2204: 2200: 2158: 2154: 2150: 2146: 2142: 2138: 2134: 2130: 2126: 2122: 2118: 2114: 2110: 2106: 2102: 2098: 2094: 2090: 2086: 2082: 2072: 2068: 2064: 2060: 2056: 2052: 2048: 2044: 2043:if Latitude 2040: 2036: 2032: 2028: 2024: 2020: 2016: 2012: 2008: 2004: 2000: 1996: 1992: 1988: 1984: 1980: 1975:= hav(| 1972: 1968: 1963:= hav(| 1960: 1952: 1944: 1935: 1731: 1728: 1659: 1656: 1645: 1641: 1637: 1633: 1629: 1625: 1621: 1617: 1613: 1609: 1606: 1602: 1598: 1589:= hav(| 1586: 1577:= hav(| 1574: 1565:= hav(| 1562: 1553:= hav(| 1550: 1541: 1488: 1458: 1244: 1233: 1215: 1211: 1207: 1203: 1199: 1195: 1191: 1187: 1183: 1179: 1175: 1171: 1167: 1163: 935: 926: 894: 793: 519: 474:The azimuth 473: 314: 284: 97: 49: 42: 21: 15: 2379:; PDF; 51kB 2133:= 0.1560 2129:= 0.6807 2105:= 0.0128 2101:= 0.2298 2063:< 180°, 2051:> 180°, 2035:< 180°, 2023:> 180°, 1005:, in which 191:declination 2441:Navigation 2435:Categories 2301:2015-11-07 2192:References 2171:Navigation 2077:An example 1585:|) 1561:|) 1236:haversines 938:haversines 2296:0886-0149 2157:= 360° - 2067:= 180° + 2055:= 180° − 2039:= 360° − 2007:) / (1 − 1979:| − 1967:| + 1889:⁡ 1883:− 1871:− 1850:⁡ 1844:− 1827:− 1806:⁡ 1800:− 1779:± 1774:∘ 1763:⁡ 1742:⁡ 1692:∘ 1684:⩽ 1678:⩽ 1673:∘ 1518:− 1513:∘ 1430:⁡ 1424:⋅ 1389:⁡ 1383:− 1368:− 1353:⁡ 1347:− 1321:− 1306:⁡ 1285:⁡ 1256:⁡ 1202:= arcsin( 1134:⁡ 1078:⁡ 1037:− 1022:⁡ 978:⋅ 972:− 951:⁡ 762:⁡ 756:⋅ 741:⁡ 735:− 714:⁡ 708:⋅ 693:⁡ 670:⁡ 640:⁡ 634:⋅ 619:⁡ 596:⁡ 590:⋅ 575:⁡ 569:− 551:⁡ 530:⁡ 442:⁡ 436:⋅ 418:⁡ 412:⋅ 394:⁡ 370:⁡ 364:⋅ 346:⁡ 325:⁡ 159:longitude 58:Algorithm 2165:See also 2161:= 233.4° 2081:Data: 1959:|) 1640:= 90° − 1597:|) 129:latitude 70:using a 2405:NavList 2047:: if 2019:: if 1628:· (1 − 1482:is the 1240:NavList 98:Given: 72:sextant 45:azimuth 30:sextant 2294:  2209:(2002) 1616:) hav( 1612:= hav( 1459:where 1194:= hav( 1182:= cos( 1170:= cos( 932:Doniol 860:, and 277:, the 221:, the 189:, the 127:, the 82:Using 2271:Paper 2151:North 1999:) = ( 26:sight 2292:ISSN 2125:: 2097:: 1995:hav( 1620:) = 915:pg.) 157:the 2147:LHA 2091:LHA 2087:Dec 2083:Lat 2061:LHA 2059:if 2049:LHA 2033:LHA 2031:if 2021:LHA 1977:Lat 1965:Lat 1957:Dec 1949:Dec 1886:hav 1847:hav 1803:hav 1760:hav 1739:hav 1614:LHA 1595:Dec 1591:Lat 1583:Dec 1579:Lat 1571:Dec 1567:Lat 1559:Dec 1555:Lat 1427:hav 1386:hav 1350:hav 1303:hav 1282:hav 1253:hav 1218:)) 1210:⋅ ( 1196:LHA 1188:Dec 1184:Lat 1176:Dec 1172:Lat 1161:. 1131:hav 1075:cos 1019:cos 948:sin 759:tan 738:tan 711:cos 690:cos 667:sin 637:cos 616:cos 593:sin 572:sin 548:sin 527:cos 494:or 439:cos 415:cos 391:cos 367:sin 343:sin 322:sin 16:In 2437:: 2286:. 2256:; 2252:; 2248:; 2244:; 2240:; 2225:; 2221:; 2155:Zn 2153:: 2123:Zn 2119:Hc 2115:ZD 2111:ZD 2095:Hc 2065:Zn 2053:Zn 2037:Zn 2027:= 2025:Zn 2011:) 2003:− 1991:+ 1987:= 1983:) 1981:Hc 1971:) 1969:Hc 1770:90 1706:. 1688:90 1642:ZD 1638:Hc 1634:ZD 1632:) 1624:+ 1618:ZD 1605:+ 1601:= 1509:90 1486:, 1242:. 1214:+ 1206:− 1200:Hc 1198:) 1190:) 1186:+ 1178:) 1174:− 1117:, 1061:, 840:, 817:. 312:: 92:Hc 90:, 86:, 84:Ho 68:Ho 40:. 20:, 2366:. 2304:. 2260:. 2159:Z 2143:Z 2139:Z 2135:n 2131:m 2127:a 2107:n 2103:m 2099:a 2069:Z 2057:Z 2045:S 2041:Z 2029:Z 2017:N 2013:Z 2009:q 2005:n 2001:a 1997:Z 1993:m 1989:n 1985:q 1973:n 1961:m 1953:a 1945:a 1919:) 1916:c 1913:H 1910:+ 1907:| 1904:t 1901:a 1898:L 1895:| 1892:( 1880:) 1877:c 1874:H 1868:| 1865:t 1862:a 1859:L 1856:| 1853:( 1841:1 1836:) 1833:c 1830:H 1824:| 1821:t 1818:a 1815:L 1812:| 1809:( 1797:) 1794:| 1791:c 1788:e 1785:D 1782:| 1766:( 1754:= 1751:) 1748:Z 1745:( 1714:Z 1681:Z 1669:0 1630:q 1626:a 1622:n 1610:a 1607:m 1603:n 1599:q 1587:m 1575:n 1563:m 1551:n 1527:) 1524:D 1521:Z 1505:( 1502:= 1499:c 1496:H 1470:D 1467:Z 1445:) 1442:A 1439:H 1436:L 1433:( 1420:) 1416:) 1413:c 1410:e 1407:D 1404:+ 1401:t 1398:a 1395:L 1392:( 1380:) 1377:c 1374:e 1371:D 1365:t 1362:a 1359:L 1356:( 1344:1 1340:( 1336:+ 1333:) 1330:c 1327:e 1324:D 1318:t 1315:a 1312:L 1309:( 1300:= 1297:) 1294:D 1291:Z 1288:( 1262:) 1259:( 1216:n 1212:m 1208:a 1204:n 1192:a 1180:m 1168:n 1149:) 1146:A 1143:H 1140:L 1137:( 1128:= 1125:a 1105:) 1102:c 1099:e 1096:D 1093:+ 1090:t 1087:a 1084:L 1081:( 1072:= 1069:m 1049:) 1046:c 1043:e 1040:D 1034:t 1031:a 1028:L 1025:( 1016:= 1013:n 993:) 990:n 987:+ 984:m 981:( 975:a 969:n 966:= 963:) 960:c 957:H 954:( 871:c 868:H 848:Z 828:o 825:H 805:o 802:H 780:. 777:) 774:t 771:a 768:L 765:( 753:) 750:c 747:H 744:( 729:) 726:t 723:a 720:L 717:( 705:) 702:c 699:H 696:( 685:) 682:c 679:e 676:D 673:( 661:= 655:) 652:t 649:a 646:L 643:( 631:) 628:c 625:H 622:( 611:) 608:t 605:a 602:L 599:( 587:) 584:c 581:H 578:( 566:) 563:c 560:e 557:D 554:( 542:= 539:) 536:Z 533:( 505:n 502:Z 482:Z 460:. 457:) 454:A 451:H 448:L 445:( 433:) 430:c 427:e 424:D 421:( 409:) 406:t 403:a 400:L 397:( 388:+ 385:) 382:c 379:e 376:D 373:( 361:) 358:t 355:a 352:L 349:( 340:= 337:) 334:c 331:H 328:( 296:c 293:H 265:n 262:o 259:L 256:+ 253:A 250:H 247:G 244:= 241:A 238:H 235:L 209:A 206:H 203:G 177:c 174:e 171:D 145:n 142:o 139:L 115:t 112:a 109:L 88:Z 74:.

Index

astronavigation
sight
sextant
line of position
intercept method
azimuth
circle of equal altitude

sextant

latitude
longitude
declination
Greenwich hour angle
local hour angle
circle of equal altitude
intercept method
haversines

haversines
NavList
zenith distance
absolute values

absolute values
Navigation
Celestial navigation
Circle of equal altitude
Intercept method
The American Practical Navigator

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.