|
For those who are interested, here are the numbers I used to derive the shape and scale of the analemmic gnomon, for a sundial with an equatorial scale of 3 inches per hour (radius 11.46".) The ephemeris data for the sun's position at 12:00 noon over longitude 90 E. was chosen to optimize position of the gnomon pattern date markings for use at longitude 90 W.
Ephemeris data for sun at 12:00 noon,
Lon. 90 E. Lat. 90 N.
Desired radius of sundial for 3"/hr is
12 x 3" / pi = 11.46"
DATE Avg AZM Avg ALT Gnomon Pattern
(Rad) (Rad) (x, ) ( ,y)
1-Jan 3.1268 -0.4017 0.169 -4.868
2-Jan 3.1248 -0.4003 0.193 -4.848
3-Jan 3.1227 -0.3987 0.216 -4.827
4-Jan 3.1207 -0.3969 0.239 -4.803
5-Jan 3.1188 -0.3950 0.262 -4.778
6-Jan 3.1168 -0.3930 0.284 -4.751
7-Jan 3.1149 -0.3909 0.306 -4.722
8-Jan 3.1130 -0.3886 0.327 -4.692
9-Jan 3.1112 -0.3862 0.348 -4.660
10-Jan 3.1094 -0.3837 0.369 -4.627
11-Jan 3.1077 -0.3811 0.389 -4.591
12-Jan 3.1060 -0.3783 0.408 -4.555
13-Jan 3.1043 -0.3754 0.427 -4.516
14-Jan 3.1027 -0.3724 0.446 -4.477
15-Jan 3.1011 -0.3693 0.464 -4.435
16-Jan 3.0996 -0.3660 0.481 -4.393
17-Jan 3.0981 -0.3627 0.498 -4.348
18-Jan 3.0967 -0.3592 0.514 -4.303
19-Jan 3.0953 -0.3556 0.530 -4.256
20-Jan 3.0940 -0.3519 0.545 -4.208
21-Jan 3.0927 -0.3481 0.560 -4.158
22-Jan 3.0915 -0.3442 0.574 -4.107
23-Jan 3.0904 -0.3401 0.587 -4.055
24-Jan 3.0893 -0.3360 0.599 -4.002
25-Jan 3.0882 -0.3318 0.611 -3.948
26-Jan 3.0872 -0.3274 0.623 -3.892
27-Jan 3.0863 -0.3230 0.633 -3.836
28-Jan 3.0854 -0.3185 0.643 -3.778
29-Jan 3.0846 -0.3138 0.653 -3.719
30-Jan 3.0838 -0.3091 0.661 -3.659
31-Jan 3.0831 -0.3043 0.669 -3.598
1-Feb 3.0825 -0.2994 0.677 -3.537
2-Feb 3.0819 -0.2944 0.683 -3.474
3-Feb 3.0814 -0.2893 0.689 -3.411
4-Feb 3.0810 -0.2841 0.694 -3.346
5-Feb 3.0806 -0.2789 0.699 -3.281
6-Feb 3.0802 -0.2735 0.703 -3.215
7-Feb 3.0800 -0.2681 0.706 -3.149
8-Feb 3.0798 -0.2627 0.708 -3.081
9-Feb 3.0796 -0.2571 0.710 -3.013
10-Feb 3.0795 -0.2515 0.711 -2.944
11-Feb 3.0795 -0.2458 0.711 -2.875
12-Feb 3.0795 -0.2400 0.711 -2.805
13-Feb 3.0796 -0.2342 0.710 -2.734
14-Feb 3.0797 -0.2283 0.709 -2.663
15-Feb 3.0799 -0.2223 0.707 -2.591
16-Feb 3.0801 -0.2163 0.704 -2.518
17-Feb 3.0804 -0.2103 0.701 -2.445
18-Feb 3.0807 -0.2041 0.697 -2.372
19-Feb 3.0811 -0.1979 0.693 -2.298
20-Feb 3.0815 -0.1917 0.688 -2.224
21-Feb 3.0820 -0.1854 0.683 -2.149
22-Feb 3.0825 -0.1791 0.677 -2.074
23-Feb 3.0831 -0.1727 0.670 -1.999
24-Feb 3.0837 -0.1663 0.663 -1.923
25-Feb 3.0843 -0.1598 0.656 -1.847
26-Feb 3.0850 -0.1533 0.648 -1.770
27-Feb 3.0858 -0.1468 0.639 -1.694
28-Feb 3.0865 -0.1402 0.631 -1.617
1-Mar 3.0873 -0.1336 0.621 -1.540
2-Mar 3.0882 -0.1269 0.612 -1.462
3-Mar 3.0891 -0.1202 0.601 -1.384
4-Mar 3.0900 -0.1135 0.591 -1.306
5-Mar 3.0910 -0.1068 0.580 -1.228
6-Mar 3.0920 -0.1000 0.569 -1.150
7-Mar 3.0930 -0.0933 0.557 -1.072
8-Mar 3.0940 -0.0865 0.545 -0.993
9-Mar 3.0951 -0.0796 0.532 -0.915
10-Mar 3.0962 -0.0728 0.520 -0.836
11-Mar 3.0974 -0.0660 0.507 -0.757
12-Mar 3.0985 -0.0591 0.493 -0.678
13-Mar 3.0997 -0.0522 0.480 -0.599
14-Mar 3.1009 -0.0453 0.466 -0.520
15-Mar 3.1021 -0.0385 0.452 -0.441
16-Mar 3.1033 -0.0316 0.438 -0.362
17-Mar 3.1046 -0.0247 0.424 -0.283
18-Mar 3.1059 -0.0178 0.409 -0.203
19-Mar 3.1071 -0.0109 0.395 -0.124
20-Mar 3.1084 -0.0039 0.380 -0.045
21-Mar 3.1097 0.0030 0.365 0.034
22-Mar 3.1110 0.0098 0.350 0.113
23-Mar 3.1123 0.0167 0.335 0.192
24-Mar 3.1136 0.0236 0.320 0.271
25-Mar 3.1149 0.0305 0.305 0.350
26-Mar 3.1163 0.0374 0.290 0.428
27-Mar 3.1176 0.0442 0.275 0.507
28-Mar 3.1189 0.0510 0.260 0.585
29-Mar 3.1202 0.0579 0.245 0.664
30-Mar 3.1215 0.0647 0.230 0.742
31-Mar 3.1228 0.0714 0.215 0.820
1-Apr 3.1241 0.0782 0.200 0.898
2-Apr 3.1254 0.0849 0.185 0.976
3-Apr 3.1267 0.0916 0.171 1.053
4-Apr 3.1280 0.0983 0.156 1.130
5-Apr 3.1292 0.1050 0.141 1.207
6-Apr 3.1305 0.1116 0.127 1.284
7-Apr 3.1317 0.1182 0.113 1.360
8-Apr 3.1330 0.1247 0.099 1.437
9-Apr 3.1342 0.1312 0.085 1.513
10-Apr 3.1354 0.1377 0.071 1.588
11-Apr 3.1365 0.1442 0.058 1.664
12-Apr 3.1377 0.1506 0.045 1.738
13-Apr 3.1388 0.1569 0.032 1.813
14-Apr 3.1399 0.1632 0.019 1.887
15-Apr 3.1410 0.1695 0.007 1.961
16-Apr 3.1421 0.1757 -0.005 2.035
17-Apr 3.1431 0.1819 -0.017 2.108
18-Apr 3.1441 0.1880 -0.029 2.180
19-Apr 3.1451 0.1941 -0.040 2.253
20-Apr 3.1460 0.2001 -0.051 2.324
21-Apr 3.1469 0.2061 -0.061 2.396
22-Apr 3.1478 0.2120 -0.071 2.466
23-Apr 3.1486 0.2179 -0.081 2.537
24-Apr 3.1494 0.2237 -0.090 2.606
25-Apr 3.1502 0.2294 -0.099 2.676
26-Apr 3.1509 0.2351 -0.107 2.744
27-Apr 3.1516 0.2407 -0.115 2.812
28-Apr 3.1523 0.2462 -0.123 2.880
29-Apr 3.1529 0.2517 -0.130 2.946
30-Apr 3.1535 0.2571 -0.137 3.012
1-May 3.1541 0.2624 -0.143 3.078
2-May 3.1546 0.2677 -0.149 3.143
3-May 3.1551 0.2728 -0.154 3.206
4-May 3.1555 0.2779 -0.159 3.270
5-May 3.1559 0.2830 -0.164 3.332
6-May 3.1563 0.2879 -0.168 3.394
7-May 3.1566 0.2928 -0.172 3.454
8-May 3.1568 0.2976 -0.175 3.514
9-May 3.1571 0.3023 -0.177 3.574
10-May 3.1573 0.3069 -0.180 3.632
11-May 3.1574 0.3115 -0.181 3.689
12-May 3.1575 0.3159 -0.183 3.745
13-May 3.1576 0.3203 -0.184 3.801
14-May 3.1576 0.3245 -0.184 3.855
15-May 3.1576 0.3287 -0.184 3.908
16-May 3.1576 0.3328 -0.183 3.961
17-May 3.1575 0.3368 -0.182 4.012
18-May 3.1573 0.3407 -0.180 4.062
19-May 3.1572 0.3445 -0.178 4.111
20-May 3.1569 0.3482 -0.176 4.159
21-May 3.1567 0.3518 -0.173 4.206
22-May 3.1564 0.3553 -0.169 4.252
23-May 3.1560 0.3587 -0.166 4.296
24-May 3.1557 0.3620 -0.161 4.339
25-May 3.1552 0.3652 -0.156 4.381
26-May 3.1548 0.3683 -0.151 4.422
27-May 3.1543 0.3713 -0.146 4.461
28-May 3.1538 0.3742 -0.140 4.499
29-May 3.1532 0.3769 -0.133 4.536
30-May 3.1526 0.3796 -0.127 4.571
31-May 3.1520 0.3821 -0.120 4.605
1-Jun 3.1514 0.3846 -0.112 4.638
2-Jun 3.1507 0.3869 -0.104 4.669
3-Jun 3.1500 0.3891 -0.096 4.699
4-Jun 3.1493 0.3912 -0.088 4.727
5-Jun 3.1485 0.3932 -0.079 4.753
6-Jun 3.1477 0.3951 -0.071 4.778
7-Jun 3.1470 0.3968 -0.061 4.802
8-Jun 3.1461 0.3985 -0.052 4.824
9-Jun 3.1453 0.4000 -0.042 4.845
10-Jun 3.1444 0.4014 -0.033 4.864
11-Jun 3.1436 0.4027 -0.023 4.881
12-Jun 3.1427 0.4039 -0.013 4.897
13-Jun 3.1418 0.4049 -0.002 4.911
14-Jun 3.1409 0.4058 0.008 4.924
15-Jun 3.1400 0.4067 0.019 4.935
16-Jun 3.1390 0.4074 0.029 4.944
17-Jun 3.1381 0.4079 0.040 4.952
18-Jun 3.1371 0.4084 0.051 4.958
19-Jun 3.1362 0.4087 0.062 4.963
20-Jun 3.1352 0.4089 0.073 4.966
21-Jun 3.1343 0.4090 0.084 4.967
22-Jun 3.1333 0.4090 0.095 4.967
23-Jun 3.1324 0.4088 0.105 4.965
24-Jun 3.1314 0.4086 0.116 4.961
25-Jun 3.1305 0.4082 0.127 4.956
26-Jun 3.1296 0.4077 0.138 4.949
27-Jun 3.1287 0.4070 0.148 4.940
28-Jun 3.1278 0.4063 0.158 4.930
29-Jun 3.1269 0.4054 0.169 4.918
30-Jun 3.1260 0.4044 0.179 4.905
1-Jul 3.1251 0.4033 0.188 4.890
2-Jul 3.1243 0.4021 0.198 4.873
3-Jul 3.1235 0.4008 0.207 4.855
4-Jul 3.1227 0.3993 0.217 4.836
5-Jul 3.1219 0.3977 0.225 4.814
6-Jul 3.1212 0.3961 0.234 4.792
7-Jul 3.1205 0.3943 0.242 4.767
8-Jul 3.1198 0.3923 0.250 4.742
9-Jul 3.1191 0.3903 0.258 4.714
10-Jul 3.1185 0.3882 0.265 4.686
11-Jul 3.1179 0.3859 0.272 4.656
12-Jul 3.1173 0.3835 0.278 4.624
13-Jul 3.1168 0.3811 0.284 4.591
14-Jul 3.1163 0.3785 0.290 4.557
15-Jul 3.1158 0.3758 0.295 4.521
16-Jul 3.1154 0.3730 0.300 4.484
17-Jul 3.1150 0.3701 0.305 4.446
18-Jul 3.1146 0.3671 0.309 4.406
19-Jul 3.1143 0.3640 0.313 4.366
20-Jul 3.1140 0.3608 0.316 4.323
21-Jul 3.1138 0.3575 0.318 4.280
22-Jul 3.1136 0.3540 0.321 4.236
23-Jul 3.1135 0.3505 0.322 4.190
24-Jul 3.1133 0.3469 0.324 4.143
25-Jul 3.1133 0.3432 0.325 4.095
26-Jul 3.1132 0.3394 0.325 4.046
27-Jul 3.1133 0.3355 0.325 3.996
28-Jul 3.1133 0.3315 0.324 3.945
29-Jul 3.1134 0.3274 0.323 3.892
30-Jul 3.1136 0.3233 0.321 3.839
31-Jul 3.1138 0.3190 0.319 3.785
1-Aug 3.1140 0.3147 0.316 3.730
2-Aug 3.1143 0.3102 0.313 3.674
3-Aug 3.1146 0.3057 0.309 3.617
4-Aug 3.1150 0.3011 0.305 3.559
5-Aug 3.1154 0.2964 0.300 3.500
6-Aug 3.1158 0.2917 0.295 3.441
7-Aug 3.1163 0.2868 0.289 3.380
8-Aug 3.1169 0.2819 0.283 3.319
9-Aug 3.1175 0.2769 0.276 3.257
10-Aug 3.1181 0.2719 0.269 3.195
11-Aug 3.1188 0.2667 0.261 3.131
12-Aug 3.1195 0.2615 0.253 3.067
13-Aug 3.1203 0.2563 0.244 3.003
14-Aug 3.1211 0.2509 0.235 2.937
15-Aug 3.1219 0.2455 0.226 2.871
16-Aug 3.1228 0.2400 0.216 2.805
17-Aug 3.1237 0.2345 0.205 2.737
18-Aug 3.1246 0.2289 0.194 2.670
19-Aug 3.1256 0.2232 0.183 2.601
20-Aug 3.1266 0.2175 0.171 2.532
21-Aug 3.1277 0.2117 0.159 2.463
22-Aug 3.1288 0.2059 0.147 2.393
23-Aug 3.1299 0.2000 0.134 2.323
24-Aug 3.1310 0.1940 0.121 2.252
25-Aug 3.1322 0.1880 0.107 2.181
26-Aug 3.1334 0.1820 0.094 2.109
27-Aug 3.1347 0.1759 0.079 2.037
28-Aug 3.1359 0.1698 0.065 1.964
29-Aug 3.1372 0.1636 0.050 1.891
30-Aug 3.1385 0.1573 0.035 1.818
31-Aug 3.1399 0.1511 0.020 1.745
1-Sep 3.1413 0.1448 0.004 1.671
2-Sep 3.1426 0.1384 -0.012 1.596
3-Sep 3.1441 0.1320 -0.028 1.522
4-Sep 3.1455 0.1256 -0.045 1.447
5-Sep 3.1469 0.1191 -0.061 1.372
6-Sep 3.1484 0.1127 -0.078 1.297
7-Sep 3.1499 0.1061 -0.095 1.221
8-Sep 3.1514 0.0996 -0.112 1.145
9-Sep 3.1529 0.0930 -0.129 1.069
10-Sep 3.1544 0.0864 -0.147 0.993
11-Sep 3.1559 0.0798 -0.164 0.916
12-Sep 3.1575 0.0731 -0.182 0.840
13-Sep 3.1590 0.0665 -0.200 0.763
14-Sep 3.1606 0.0598 -0.217 0.686
15-Sep 3.1621 0.0531 -0.235 0.609
16-Sep 3.1637 0.0463 -0.253 0.531
17-Sep 3.1652 0.0396 -0.271 0.454
18-Sep 3.1668 0.0329 -0.289 0.377
19-Sep 3.1683 0.0261 -0.307 0.299
20-Sep 3.1699 0.0193 -0.324 0.221
21-Sep 3.1714 0.0125 -0.342 0.144
22-Sep 3.1730 0.0057 -0.360 0.066
23-Sep 3.1745 -0.0011 -0.377 -0.012
24-Sep 3.1760 -0.0079 -0.395 -0.090
25-Sep 3.1776 -0.0147 -0.412 -0.168
26-Sep 3.1791 -0.0215 -0.429 -0.246
27-Sep 3.1805 -0.0283 -0.446 -0.324
28-Sep 3.1820 -0.0351 -0.463 -0.402
29-Sep 3.1835 -0.0419 -0.480 -0.480
30-Sep 3.1849 -0.0487 -0.496 -0.558
1-Oct 3.1863 -0.0554 -0.513 -0.636
2-Oct 3.1877 -0.0622 -0.529 -0.714
3-Oct 3.1891 -0.0690 -0.544 -0.791
4-Oct 3.1905 -0.0757 -0.560 -0.869
5-Oct 3.1918 -0.0824 -0.575 -0.947
6-Oct 3.1931 -0.0891 -0.590 -1.024
7-Oct 3.1944 -0.0958 -0.604 -1.102
8-Oct 3.1956 -0.1025 -0.619 -1.179
9-Oct 3.1968 -0.1092 -0.633 -1.256
10-Oct 3.1980 -0.1158 -0.646 -1.333
11-Oct 3.1992 -0.1224 -0.659 -1.409
12-Oct 3.2003 -0.1290 -0.672 -1.486
13-Oct 3.2013 -0.1355 -0.684 -1.562
14-Oct 3.2024 -0.1420 -0.696 -1.638
15-Oct 3.2034 -0.1485 -0.708 -1.714
16-Oct 3.2043 -0.1549 -0.719 -1.790
17-Oct 3.2053 -0.1613 -0.729 -1.865
18-Oct 3.2061 -0.1677 -0.739 -1.940
19-Oct 3.2070 -0.1740 -0.749 -2.015
20-Oct 3.2077 -0.1803 -0.757 -2.089
21-Oct 3.2085 -0.1866 -0.766 -2.163
22-Oct 3.2092 -0.1928 -0.774 -2.237
23-Oct 3.2098 -0.1989 -0.781 -2.310
24-Oct 3.2104 -0.2050 -0.788 -2.383
25-Oct 3.2109 -0.2111 -0.794 -2.455
26-Oct 3.2114 -0.2170 -0.799 -2.527
27-Oct 3.2118 -0.2230 -0.804 -2.598
28-Oct 3.2122 -0.2289 -0.808 -2.669
29-Oct 3.2125 -0.2347 -0.812 -2.740
30-Oct 3.2128 -0.2404 -0.815 -2.810
31-Oct 3.2130 -0.2461 -0.817 -2.879
1-Nov 3.2131 -0.2518 -0.819 -2.948
2-Nov 3.2132 -0.2573 -0.820 -3.016
3-Nov 3.2133 -0.2628 -0.821 -3.083
4-Nov 3.2132 -0.2682 -0.820 -3.150
5-Nov 3.2131 -0.2736 -0.819 -3.216
6-Nov 3.2130 -0.2789 -0.818 -3.281
7-Nov 3.2128 -0.2840 -0.815 -3.345
8-Nov 3.2125 -0.2892 -0.812 -3.409
9-Nov 3.2122 -0.2942 -0.809 -3.472
10-Nov 3.2118 -0.2991 -0.804 -3.534
11-Nov 3.2114 -0.3040 -0.799 -3.595
12-Nov 3.2109 -0.3088 -0.793 -3.655
13-Nov 3.2103 -0.3135 -0.787 -3.715
14-Nov 3.2097 -0.3181 -0.779 -3.773
15-Nov 3.2090 -0.3226 -0.771 -3.830
16-Nov 3.2082 -0.3270 -0.763 -3.886
17-Nov 3.2074 -0.3313 -0.754 -3.942
18-Nov 3.2065 -0.3355 -0.743 -3.996
19-Nov 3.2056 -0.3396 -0.733 -4.049
20-Nov 3.2046 -0.3436 -0.721 -4.100
21-Nov 3.2035 -0.3475 -0.709 -4.151
22-Nov 3.2024 -0.3513 -0.696 -4.200
23-Nov 3.2012 -0.3550 -0.683 -4.248
24-Nov 3.2000 -0.3586 -0.669 -4.295
25-Nov 3.1987 -0.3621 -0.654 -4.341
26-Nov 3.1973 -0.3655 -0.638 -4.385
27-Nov 3.1959 -0.3687 -0.622 -4.427
28-Nov 3.1945 -0.3718 -0.606 -4.469
29-Nov 3.1930 -0.3748 -0.588 -4.509
30-Nov 3.1914 -0.3777 -0.571 -4.547
1-Dec 3.1898 -0.3805 -0.552 -4.584
2-Dec 3.1881 -0.3832 -0.533 -4.619
3-Dec 3.1864 -0.3857 -0.514 -4.653
4-Dec 3.1847 -0.3881 -0.494 -4.685
5-Dec 3.1829 -0.3904 -0.474 -4.716
6-Dec 3.1811 -0.3926 -0.453 -4.745
7-Dec 3.1793 -0.3946 -0.431 -4.772
8-Dec 3.1774 -0.3965 -0.410 -4.797
9-Dec 3.1754 -0.3982 -0.388 -4.821
10-Dec 3.1735 -0.3999 -0.365 -4.843
11-Dec 3.1715 -0.4014 -0.342 -4.864
12-Dec 3.1695 -0.4028 -0.319 -4.882
13-Dec 3.1674 -0.4040 -0.296 -4.899
14-Dec 3.1654 -0.4051 -0.272 -4.914
15-Dec 3.1633 -0.4061 -0.248 -4.927
16-Dec 3.1612 -0.4069 -0.224 -4.939
17-Dec 3.1590 -0.4076 -0.200 -4.948
18-Dec 3.1569 -0.4082 -0.176 -4.956
19-Dec 3.1548 -0.4086 -0.151 -4.962
20-Dec 3.1526 -0.4089 -0.126 -4.966
21-Dec 3.1504 -0.4091 -0.101 -4.968
22-Dec 3.1483 -0.4091 -0.076 -4.968
23-Dec 3.1461 -0.4090 -0.052 -4.966
24-Dec 3.1439 -0.4087 -0.027 -4.963
25-Dec 3.1417 -0.4083 -0.002 -4.958
26-Dec 3.1396 -0.4078 0.023 -4.950
27-Dec 3.1374 -0.4071 0.048 -4.941
28-Dec 3.1353 -0.4063 0.072 -4.930
29-Dec 3.1331 -0.4054 0.097 -4.918
30-Dec 3.1310 -0.4043 0.121 -4.903
31-Dec 3.1289 -0.4031 0.145 -4.887
Last Updated: November 1, 1998
|