(42S) Sun Approximate Declination, Altitude, and Azimuth

[Eddie W. Shore]

Original Post: http://edspi31415.blogspot.com/2013/06/h...-pond.html

Input: Days after the vernal equinox (typically March 21), Earth’s latitude (north/south), number of hours after local noon (example: for 7 AM, enter -5. For 7 PM, enter 7).

Code:


00 { 147-Byte Prgm }
01 LBL “SUNAA”
02 DEG
03 “DAYS AFTER EQ.”
04 PROMPT
05 STO 00
06 “LATTITUDE”
07 PROMPT
08 STO 01
09 “HRS AFTER NOON”
10 PROMPT
11 STO 02
12 0.9856
13 RCL* 00
14 SIN
15 23.45
16 *
17 STO 04
18 COS
19 RCL 01
20 COS
21 *
22 15
23 RCL* 02
24 COS
25 *
26 RCL 01
27 SIN
28 RCL 04
29 SIN
30 *
31 +
32 ASIN
33 STO 05
34 SIN
35 RCL 01
36 SIN
37 *
38 RCL 04
39 SIN
40 –
41 RCL 05
42 COS
43 RCL 01
44 COS
45 *
46 ÷ 
47 ACOS
48 STO 06
49 RCL 04
50 “DECLINATION”
51 AVIEW
52 STOP
53 RCL 05
54 “ALTITUDE”
55 AVIEW
56 STOP
57 RCL 06
58 “AZIMUTH”
59 AVIEW
60 END

Example:

Input: 100 days after the vernal equinox, 43.72° N, about 12 noon (T = 0)
Results: Declination ≈ 23.1888°, Altitude: 69.4688°, Azimuth: 0.0002°