SUN POSITION CALCULATOR

This version is made for racket and it can be run in DrRacket and in command line. The input data is read from the text file indata.txt. You can edit it so as you like. There are some files made for Stockholm, New York and Sydney.

Input data file indata.txt

Here is the description of the saved input data

  1 0        ; year      year number, current time if 0
  2 0        ; month     month number, current time if 0
  3 0        ; day       day of the month, current time if 0
  4 65.85    ; latitude  degrees
  5 24.18    ; longitude degrees
  6 2        ; time zone hours
  7 10       ; calculation time, ***hour UTC***, fixed, can be edited
  8 32.      ; calculation time, minutes, fixed, can be edited
  9 41       ; calculation time, seconds, fixed, can be edited
 10 Tornio.  ; location name

If values of year, month or day are zeroes, the current time is used.

Using from command line

You can run this e.g. in the bash shell if you have installed racket.

running the source file

$ racket suncalctoday.rkt

running the compiled code

Alternatively, the program can be started from the command file suncal.rkt which requires the compiled code as follows:

$ racket suncal.rkt

This is the start code suncal.rkt running the compiled program:

#lang racket
(require "suncalctoday.rkt")

; This file runs the compiled binary files
; You can run the compiled files on bash command line with racket:
;    racket suncalc.rkt
; See https://docs.racket-lang.org/raco/Bytecode_Files.html

The source code may be compiled with raco as follows:

$ raco make suncalctoday.rkt

The compiled files can be seen in the directory compiled:

-rw-r--r--  1 jla   staff  38120 12 Maa 12:44 suncalctoday_rkt.zo
-rw-r--r--  1 jla   staff    214 12 Maa 12:44 suncalctoday_rkt.dep
-rw-r--r--  1 jla   staff   5118 12 Maa 12:44 suncal_rkt.zo
-rw-r--r--  1 jla   staff    227 12 Maa 12:44 suncal_rkt.dep

Example Stockholm date 2021-03-20

jla$ racket suncal.rkt 
 Date 2021-3-20 Latitude 59.329  Longitude 18.069 Timezone 1 in Stockholm
 Nautical twilight   2021-03-20 ~ 04:18:45
 Civil twilight time 2021-03-20 ~ 05:07:40
 Sunrise time        2021-03-20 ~ 05:48:26
 Noon time           2021-03-20 ~ 11:55:06
 Sunset time         2021-03-20 ~ 18:01:46
 Civil twilight time 2021-03-20 ~ 18:42:32
 Nautical twilight   2021-03-20 ~ 19:31:28
 Daylength           2021-03-20 ~ 12:13:20
 Sun declination       0.0201°
 Zenith at noon        59.3089°
 Sun elevation corr.   30.7182°
 Atmospher. refraction 0.0271°
 Azimuth at sunrise    88.5558°
 Azimuth at noon       180.0016°
 Azimuth at sunset     271.4442°
 Julian day        2459294
 Local time JD     2459293.9549

 Calculation time:   11:55:07 (UTC+1)
 City: Stockholm  Latitude    59.329° N , longitude 18.069° E

 ==========================================

Current seconds 1616237707
Hour angle              0.0014°
Solar elevation         30.6911°
jla$