This commit is contained in:
hueso 2025-05-16 18:41:17 -03:00
parent 48399312be
commit 13863d32ca
3 changed files with 151 additions and 151 deletions

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@ -2,36 +2,37 @@
//
// This software minimizes computational work by performing the full calculation
// of the lunar position three times, at the beginning, middle, and end of the
// period of interest. Three point interpolation is used to predict the position
// for each hour, and the arithmetic mean is used to predict the half-hour positions.
// period of interest. Three point interpolation is used to predict the
// position for each hour, and the arithmetic mean is used to predict the
// half-hour positions.
//
// The full computational burden is negligible on modern computers, but the
// algorithm is effective and still useful for small embedded systems.
//
// This software was originally adapted to javascript by Stephen R. Schmitt
// from a BASIC program from the 'Astronomical Computing' column of Sky & Telescope,
// April 1989, page 78.
// from a BASIC program from the 'Astronomical Computing' column of Sky &
// Telescope, April 1989, page 78.
//
// Subsequently adapted from Stephen R. Schmitt's javascript to c++ for the Arduino
// by Cyrus Rahman.
// Subsequently adapted from Stephen R. Schmitt's javascript to c++ for the
// Arduino by Cyrus Rahman.
//
// Subsequently adapted from Cyrus Rahman's Arduino C++ to C for the Sensor Watch
// by hueso, this work is subject to Stephen Schmitt's copyright:
// Subsequently adapted from Cyrus Rahman's Arduino C++ to C for the Sensor
// Watch by hueso, this work is subject to Stephen Schmitt's copyright:
//
// Copyright 2007 Stephen R. Schmitt
// Copyright 2007 Stephen R. Schmitt
// Subsequent work Copyright 2020 Cyrus Rahman
// You may use or modify this source code in any way you find useful, provided
// that you agree that the author(s) have no warranty, obligations or liability. You
// must determine the suitability of this source code for your use.
// that you agree that the author(s) have no warranty, obligations or liability.
// You must determine the suitability of this source code for your use.
//
// Redistributions of this source code must retain this copyright notice.
#include "moonrise.h"
#include <math.h>
#include <stdbool.h>
#include <stdlib.h>
#include "moonrise.h"
#define K1 15*(M_PI/180)*1.0027379
#define K1 15 * (M_PI / 180) * 1.0027379
// Determine the nearest moon rise or set event previous, and the nearest
// moon rise or set event subsequent, to the specified time in seconds since the
@ -40,15 +41,15 @@
//
// We look for events from MR_WINDOW/2 hours in the past to MR_WINDOW/2 hours
// in the future.
MoonRise MoonRise_calculate(double latitude, double longitude, time_t t) {
MoonRise self;
MoonRise MoonRise_calculate(double latitude, double longitude, uint32_t t) {
MoonRise self = {};
skyCoordinates moonPosition[3];
double offsetDays;
self.queryTime = t;
offsetDays = julianDate(t) - 2451545L; // Days since Jan 1, 2000, 1200UTC.
offsetDays = julianDate(t) - 2451545L; // Days since Jan 1, 2000, 1200UTC.
// Begin testing (MR_WINDOW / 2) hours before requested time.
//offsetDays -= (double)MR_WINDOW / (2 * 24) ;
// offsetDays -= (double)MR_WINDOW / (2 * 24) ;
// Calculate coordinates at start, middle, and end of search period.
for (int i = 0; i < 3; i++) {
@ -64,142 +65,150 @@ MoonRise MoonRise_calculate(double latitude, double longitude, time_t t) {
// Initialize interpolation array.
skyCoordinates mpWindow[3];
mpWindow[0].RA = moonPosition[0].RA;
mpWindow[0].RA = moonPosition[0].RA;
mpWindow[0].declination = moonPosition[0].declination;
mpWindow[0].distance = moonPosition[0].distance;
for (int k = 0; k < MR_WINDOW; k++) { // Check each interval of search period
float ph = (float)(k + 1)/MR_WINDOW;
mpWindow[2].RA = interpolate(moonPosition[0].RA,
moonPosition[1].RA,
moonPosition[2].RA, ph);
mpWindow[2].declination = interpolate(moonPosition[0].declination,
moonPosition[1].declination,
moonPosition[2].declination, ph);
for (int k = 0; k < MR_WINDOW; k++) { // Check each interval of search period
float ph = (float)(k + 1) / MR_WINDOW;
mpWindow[2].RA = interpolate(moonPosition[0].RA, moonPosition[1].RA,
moonPosition[2].RA, ph);
mpWindow[2].declination =
interpolate(moonPosition[0].declination, moonPosition[1].declination,
moonPosition[2].declination, ph);
mpWindow[2].distance = moonPosition[2].distance;
// Look for moonrise/set events during this interval.
{
double ha[3], VHz[3];
double lSideTime;
double ha[3], VHz[3];
double lSideTime;
// Get (local_sidereal_time - MR_WINDOW / 2) hours in radians.
lSideTime = localSiderealTime(offsetDays, longitude) * 2* M_PI / 360;
// Get (local_sidereal_time - MR_WINDOW / 2) hours in radians.
lSideTime = localSiderealTime(offsetDays, longitude) * 2 * M_PI / 360;
// Calculate Hour Angle.
ha[0] = lSideTime - mpWindow[0].RA + k*K1;
ha[2] = lSideTime - mpWindow[2].RA + k*K1 + K1;
// Calculate Hour Angle.
ha[0] = lSideTime - mpWindow[0].RA + k * K1;
ha[2] = lSideTime - mpWindow[2].RA + k * K1 + K1;
// Hour Angle and declination at half hour.
ha[1] = (ha[2] + ha[0])/2;
mpWindow[1].declination = (mpWindow[2].declination + mpWindow[0].declination)/2;
// Hour Angle and declination at half hour.
ha[1] = (ha[2] + ha[0]) / 2;
mpWindow[1].declination =
(mpWindow[2].declination + mpWindow[0].declination) / 2;
double s = sin(M_PI / 180 * latitude);
double c = cos(M_PI / 180 * latitude);
double s = sin(M_PI / 180 * latitude);
double c = cos(M_PI / 180 * latitude);
// refraction + semidiameter at horizon + distance correction
double z = cos(M_PI / 180 * (90.567 - 41.685 / mpWindow[0].distance));
// refraction + semidiameter at horizon + distance correction
double z = cos(M_PI / 180 * (90.567 - 41.685 / mpWindow[0].distance));
VHz[0] = s * sin(mpWindow[0].declination) + c * cos(mpWindow[0].declination) * cos(ha[0]) - z;
VHz[2] = s * sin(mpWindow[2].declination) + c * cos(mpWindow[2].declination) * cos(ha[2]) - z;
VHz[0] = s * sin(mpWindow[0].declination) +
c * cos(mpWindow[0].declination) * cos(ha[0]) - z;
VHz[2] = s * sin(mpWindow[2].declination) +
c * cos(mpWindow[2].declination) * cos(ha[2]) - z;
if (signbit(VHz[0]) == signbit(VHz[2]))
goto noevent; // No event this hour.
if (signbit(VHz[0]) == signbit(VHz[2]))
goto noevent; // No event this hour.
VHz[1] = s * sin(mpWindow[1].declination) + c * cos(mpWindow[1].declination) * cos(ha[1]) - z;
VHz[1] = s * sin(mpWindow[1].declination) +
c * cos(mpWindow[1].declination) * cos(ha[1]) - z;
double a, b, d, e, time;
a = 2 * VHz[2] - 4 * VHz[1] + 2 * VHz[0];
b = 4 * VHz[1] - 3 * VHz[0] - VHz[2];
d = b * b - 4 * a * VHz[0];
double a, b, d, e, time;
a = 2 * VHz[2] - 4 * VHz[1] + 2 * VHz[0];
b = 4 * VHz[1] - 3 * VHz[0] - VHz[2];
d = b * b - 4 * a * VHz[0];
if (d < 0)
goto noevent; // No event this hour.
if (d < 0)
goto noevent; // No event this hour.
d = sqrt(d);
e = (-b + d) / (2 * a);
if ((e < 0) || (e > 1))
d = sqrt(d);
e = (-b + d) / (2 * a);
if ((e < 0) || (e > 1))
e = (-b - d) / (2 * a);
time = k + e + 1 / 120; // Time since k=0 of event (in hours).
time = k + e + 1 / 120; // Time since k=0 of event (in hours).
// The time we started searching + the time from the start of the search to the
// event is the time of the event.
time_t eventTime;
eventTime = self.queryTime + (time) *60 *60;
// The time we started searching + the time from the start of the search
// to the event is the time of the event.
uint32_t eventTime;
eventTime = self.queryTime + (time) * 60 * 60;
double hz, nz, dz, az;
hz = ha[0] + e * (ha[2] - ha[0]); // Azimuth of the moon at the event.
nz = -cos(mpWindow[1].declination) * sin(hz);
dz = c * sin(mpWindow[1].declination) - s * cos(mpWindow[1].declination) * cos(hz);
az = atan2(nz, dz) / (M_PI / 180);
if (az < 0)
double hz, nz, dz, az;
hz = ha[0] + e * (ha[2] - ha[0]); // Azimuth of the moon at the event.
nz = -cos(mpWindow[1].declination) * sin(hz);
dz = c * sin(mpWindow[1].declination) -
s * cos(mpWindow[1].declination) * cos(hz);
az = atan2(nz, dz) / (M_PI / 180);
if (az < 0)
az += 360;
// If there is no previously recorded event of this type, save this event.
//
// If this event is previous to queryTime, and is the nearest event to queryTime
// of events of its type previous to queryType, save this event, replacing the
// previously recorded event of its type. Events subsequent to queryTime are
// treated similarly, although since events are tested in chronological order
// no replacements will occur as successive events will be further from
// queryTime.
//
// If this event is subsequent to queryTime and there is an event of its type
// previous to queryTime, then there is an event of the other type between the
// two events of this event's type. If the event of the other type is
// previous to queryTime, then it is the nearest event to queryTime that is
// previous to queryTime. In this case save the current event, replacing
// the previously recorded event of its type. Otherwise discard the current
// event.
//
if ((VHz[0] < 0) && (VHz[2] > 0)) {
if (!self.hasRise ||
// If there is no previously recorded event of this type, save this event.
//
// If this event is previous to queryTime, and is the nearest event to
// queryTime of events of its type previous to queryType, save this event,
// replacing the previously recorded event of its type. Events subsequent
// to queryTime are treated similarly, although since events are tested in
// chronological order no replacements will occur as successive events
// will be further from queryTime.
//
// If this event is subsequent to queryTime and there is an event of its
// type previous to queryTime, then there is an event of the other type
// between the two events of this event's type. If the event of the other
// type is previous to queryTime, then it is the nearest event to
// queryTime that is previous to queryTime. In this case save the current
// event, replacing the previously recorded event of its type. Otherwise
// discard the current event.
//
if ((VHz[0] < 0) && (VHz[2] > 0)) {
if (!self.hasRise ||
((self.riseTime < self.queryTime) == (eventTime < self.queryTime) &&
llabs(self.riseTime - self.queryTime) > llabs(eventTime - self.queryTime)) ||
(self.riseTime - self.queryTime) > (eventTime - self.queryTime)) ||
((self.riseTime < self.queryTime) != (eventTime < self.queryTime) &&
(self.hasSet &&
(self.riseTime < self.queryTime) == (self.setTime < self.queryTime)))) {
self.riseTime = eventTime;
self.riseAz = az;
self.hasRise = true;
}
(self.hasSet && (self.riseTime < self.queryTime) ==
(self.setTime < self.queryTime)))) {
self.riseTime = eventTime;
self.riseAz = az;
self.hasRise = true;
}
if ((VHz[0] > 0) && (VHz[2] < 0)) {
if (!self.hasSet ||
}
if ((VHz[0] > 0) && (VHz[2] < 0)) {
if (!self.hasSet ||
((self.setTime < self.queryTime) == (eventTime < self.queryTime) &&
llabs(self.setTime - self.queryTime) > llabs(eventTime - self.queryTime)) ||
(self.setTime - self.queryTime) > (eventTime - self.queryTime)) ||
((self.setTime < self.queryTime) != (eventTime < self.queryTime) &&
(self.hasRise &&
(self.setTime < self.queryTime) == (self.riseTime < self.queryTime)))) {
self.setTime = eventTime;
self.setAz = az;
self.hasSet = true;
}
(self.hasRise && (self.setTime < self.queryTime) ==
(self.riseTime < self.queryTime)))) {
self.setTime = eventTime;
self.setAz = az;
self.hasSet = true;
}
}
noevent:
// There are obscure cases in the polar regions that require extra logic.
if (!self.hasRise && !self.hasSet)
noevent:
// There are obscure cases in the polar regions that require extra logic.
if (!self.hasRise && !self.hasSet)
self.isVisible = !signbit(VHz[2]);
else if (self.hasRise && !self.hasSet)
else if (self.hasRise && !self.hasSet)
self.isVisible = (self.queryTime > self.riseTime);
else if (!self.hasRise && self.hasSet)
else if (!self.hasRise && self.hasSet)
self.isVisible = (self.queryTime < self.setTime);
else
self.isVisible = ((self.riseTime < self.setTime && self.riseTime < self.queryTime && self.setTime > self.queryTime) ||
(self.riseTime > self.setTime && (self.riseTime < self.queryTime || self.setTime > self.queryTime)));
else
self.isVisible =
((self.riseTime < self.setTime && self.riseTime < self.queryTime &&
self.setTime > self.queryTime) ||
(self.riseTime > self.setTime && (self.riseTime < self.queryTime ||
self.setTime > self.queryTime)));
}
}
if (self.hasSet && self.hasRise)
break;
mpWindow[0] = mpWindow[2]; // Advance to next interval.
mpWindow[0] = mpWindow[2]; // Advance to next interval.
}
return self;
}
// Moon position using fundamental arguments
// Moon position using fundamental arguments
// (Van Flandern & Pulkkinen, 1979)
skyCoordinates moon(double dayOffset) {
double l = 0.606434 + 0.03660110129 * dayOffset;
@ -275,7 +284,7 @@ double interpolate(double f0, double f1, double f2, double p) {
// Determine Julian date from Unix time.
// Provides marginally accurate results with Arduino 4-byte double.
double julianDate(time_t t) {
double julianDate(uint32_t t) {
return (t / 86400.0L + 2440587.5);
}

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@ -1,8 +1,7 @@
#ifndef MoonRise_h
#define MoonRise_h
#include <time.h>
#include <stdint.h>
// Size of event search window in hours.
// Events further away from the search time than MR_WINDOW/2 will not be
// found. At higher latitudes the moon rise/set intervals become larger, so if
@ -10,33 +9,33 @@
// windows will increase interpolation error. Useful values are probably from
// 12 - 48 but will depend upon your application.
#define MR_WINDOW 72 // Even integer
#define MR_WINDOW 48 // Even integer
typedef struct {
double RA; // Right ascension
double declination; // Declination
double distance; // Distance
double RA; // Right ascension
double declination; // Declination
double distance; // Distance
} skyCoordinates;
typedef struct {
time_t queryTime;
time_t riseTime;
time_t setTime;
float riseAz;
float setAz;
bool hasRise;
bool hasSet;
bool isVisible;
uint32_t queryTime;
uint32_t riseTime;
uint32_t setTime;
float riseAz;
float setAz;
bool hasRise;
bool hasSet;
bool isVisible;
} MoonRise;
MoonRise MoonRise_calculate(double latitude, double longitude, time_t t);
MoonRise MoonRise_calculate(double latitude, double longitude, uint32_t t);
// private:
void testMoonRiseSet(MoonRise *self, int i, double offsetDays, double latitude, double longitude,
skyCoordinates *mp);
void testMoonRiseSet(MoonRise *self, int i, double offsetDays, double latitude,
double longitude, skyCoordinates *mp);
skyCoordinates moon(double dayOffset);
double interpolate(double f0, double f1, double f2, double p);
double julianDate(time_t t);
double julianDate(uint32_t t);
double localSiderealTime(double offsetDays, double longitude);
#endif

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@ -52,7 +52,7 @@ static void _moonrise_face_update(movement_settings_t *settings, moonrise_state_
if (movement_location.reg == 0) {
watch_clear_colon();
watch_display_string("MR no Loc", 0);
watch_display_string("Mz no Loc", 0);
return;
}
@ -60,15 +60,10 @@ static void _moonrise_face_update(movement_settings_t *settings, moonrise_state_
watch_date_time scratch_time; // scratchpad, contains different values at different times
scratch_time.reg = date_time.reg;
// Weird quirky unsigned things were happening when I tried to cast these directly to doubles below.
// it looks redundant, but extracting them to local int16's seemed to fix it.
int16_t lat_centi = (int16_t)movement_location.bit.latitude;
int16_t lon_centi = (int16_t)movement_location.bit.longitude;
double lat = (double)movement_location.bit.latitude / 100.0;
double lon = (double)movement_location.bit.longitude / 100.0;
double lat = (double)lat_centi / 100.0;
double lon = (double)lon_centi / 100.0;
time_t t = watch_utility_date_time_to_unix_time(scratch_time, movement_timezone_offsets[settings->bit.time_zone] * 60);
uint32_t t = watch_utility_date_time_to_unix_time(date_time, movement_timezone_offsets[settings->bit.time_zone] * 60);
MoonRise mr = MoonRise_calculate(lat, lon, t);
if(mr.isVisible)
@ -76,11 +71,12 @@ static void _moonrise_face_update(movement_settings_t *settings, moonrise_state_
else
watch_clear_indicator(WATCH_INDICATOR_LAP);
if (!mr.hasRise && !mr.hasSet) {
if ( (state->rise_index == 0 && !mr.hasRise) ||
(state->rise_index == 1 && !mr.hasSet) ) {
watch_clear_colon();
watch_clear_indicator(WATCH_INDICATOR_PM);
watch_clear_indicator(WATCH_INDICATOR_24H);
snprintf(buf, sizeof(buf), "MR%2d none ", scratch_time.unit.day);
snprintf(buf, sizeof(buf), "%s%2d none ", state->rise_index ? "M_" : "M~", scratch_time.unit.day);
watch_display_string(buf, 0);
return;
}
@ -95,7 +91,6 @@ static void _moonrise_face_update(movement_settings_t *settings, moonrise_state_
state->rise_set_expires.reg = scratch_time.reg;
bool set_leading_zero = false;
if (!settings->bit.clock_mode_24h)
if (watch_utility_convert_to_12_hour(&scratch_time))
@ -105,12 +100,9 @@ static void _moonrise_face_update(movement_settings_t *settings, moonrise_state_
else if (settings->bit.clock_24h_leading_zero && scratch_time.unit.hour < 10) {
set_leading_zero = true;
}
snprintf(buf, sizeof(buf), "M %2d%2d%02d%2s", scratch_time.unit.day, scratch_time.unit.hour, scratch_time.unit.minute,longLatPresets[state->longLatToUse].name);
snprintf(buf, sizeof(buf), "%s%2d%2d%02d%2s", state->rise_index ? "M_" : "M~", scratch_time.unit.day, scratch_time.unit.hour, scratch_time.unit.minute,longLatPresets[state->longLatToUse].name);
watch_display_string(buf, 0);
if(state->rise_index == 0)
watch_set_pixel(0,11);
else
watch_set_pixel(2,11);
if (set_leading_zero)
watch_display_string("0", 4);
return;