public Ephemerides GetObservationDetails(PlanningFilter filter, CelestialObject body)
{
var ctx = new SkyContext(filter.JulianDayMidnight, filter.ObserverLocation, preferFast: true);
ctx.MinBodyAltitudeForVisibilityCalculations = filter.MinBodyAltitude;
ctx.MaxSunAltitudeForVisibilityCalculations = filter.MaxSunAltitude;
return(GetObservationDetails(filter, ctx, body, force: true));
}
public ICollection <Ephemerides> CreatePlan(PlanningFilter filter, CancellationToken?token = null, IProgress <double> progress = null)
{
double timeFrom = filter.TimeFrom / 24.0;
double timeTo = filter.TimeTo / 24.0;
double obsDuration = timeTo < timeFrom ? timeTo - timeFrom + 1 : timeTo - timeFrom;
int countLimit = filter.CountLimit ?? 1000;
// Planned observation range, expressed as circular sector (angles)
// It represents a timeframe to be compared with each celestial body visibility conditions.
AngleRange obsRange = new AngleRange(timeFrom * 360, obsDuration * 360);
// Resulting list of ephemerides. Each item is a planned observation of a celestial body.
List <Ephemerides> ephemerides = new List <Ephemerides>();
// Context used for calculations. We use local midnight as a time reference to obtain
// general conditions of visibility of celestial bodies,
// and after that apply desired timeframe to find intersections.
var context = new SkyContext(filter.JulianDayMidnight, filter.ObserverLocation, true);
context.MinBodyAltitudeForVisibilityCalculations = filter.MinBodyAltitude;
context.MaxSunAltitudeForVisibilityCalculations = filter.MaxSunAltitude;
IEnumerable <CelestialObject> celestialObjects = null;
// create plan from predefined list of objects
if (filter.CelestialObjects.Any())
{
celestialObjects = filter.CelestialObjects;
}
// create plan from objects types filter
else if (filter.CelestialObjectsTypes.Any())
{
celestialObjects = sky.CelestialObjects.Where(b => filter.CelestialObjectsTypes.Contains(b.Type));
}
// filter is uncomplete!
else
{
throw new ArgumentException("Filter must contain either celestial objects list or celestial objects types list.");
}
// Total objects count
double objectsCount = filter.CountLimit ?? celestialObjects.Count();
int counter = 0;
foreach (CelestialObject body in celestialObjects)
{
if (token.HasValue && token.Value.IsCancellationRequested)
{
ephemerides.Clear();
break;
}
if (ephemerides.Count >= countLimit)
{
break;
}
progress?.Report(counter++ / objectsCount * 100);
var e = GetObservationDetails(filter, context, body, !filter.ApplyFilters);
if (e != null)
{
ephemerides.Add(e);
}
}
return(ephemerides);
}
private Ephemerides GetObservationDetails(PlanningFilter filter, SkyContext context, CelestialObject body, bool force = false)
{
float? magLimit = filter.MagLimit;
double timeFrom = filter.TimeFrom / 24.0;
double timeTo = filter.TimeTo / 24.0;
double obsDuration = timeTo < timeFrom ? timeTo - timeFrom + 1 : timeTo - timeFrom;
double?durationLimit = filter.DurationLimit != null ? filter.DurationLimit / 60.0 : null;
// Planned observation range, expressed as circular sector (angles)
// It represents a timeframe to be compared with each celestial body visibility conditions.
AngleRange obsRange = new AngleRange(timeFrom * 360, obsDuration * 360);
// Ephemerides for particular celestial body
Ephemerides bodyEphemerides = new Ephemerides(body);
// Ephemerides available for the body
var categories = sky.GetEphemerisCategories(body);
var visibilityEphems = sky.GetEphemerides(body, context, new[] {
"Visibility.Begin",
"Visibility.End",
"Visibility.Duration",
"RTS.Rise",
"RTS.Transit",
"RTS.Set",
"RTS.RiseAzimuth",
"RTS.TransitAltitude",
"RTS.SetAzimuth",
"Magnitude"
});
bodyEphemerides.AddRange(visibilityEphems);
// Body does not have magnitude
if (!categories.Contains("Magnitude"))
{
if (!force && filter.SkipUnknownMagnitude)
{
return(null);
}
// Apply "skip unknown mag" filter
bodyEphemerides.Add(new Ephemeris("Magnitude", null, Formatters.Magnitude));
}
if (!force && filter.MagLimit != null)
{
float?mag = bodyEphemerides.GetValue <float?>("Magnitude");
// Apply magnitude filter
if (mag > magLimit)
{
return(null);
}
}
// If body has visibility ephemerides, it can be planned.
if (categories.Contains("Visibility.Duration"))
{
double visDuration = visibilityEphems.GetValue <double>("Visibility.Duration");
if (visDuration > 0)
{
Date visBegin = visibilityEphems.GetValue <Date>("Visibility.Begin");
AngleRange visRange = new AngleRange(visBegin.Time * 360, visDuration / 24 * 360);
var ranges = visRange.Overlaps(obsRange);
if (ranges.Any())
{
double beginTime = ranges.First().Start / 360;
if (beginTime < timeFrom)
{
beginTime += 1;
}
double endTime = beginTime + ranges.First().Range / 360;
// Begin of body observation, limited by desired observation begin and end time,
// and expressed in Date
Date bodyObsBegin = new Date(context.JulianDayMidnight + beginTime, context.GeoLocation.UtcOffset);
// Real duration of body observation, limited by desired observation begin and end time,
// and expressed in hours (convert from angle range expressed in degrees):
double bodyObsDuration = ranges.First().Range / 360 * 24;
// Apply duration filter
if (!force && durationLimit > bodyObsDuration)
{
return(null);
}
// End of body observation, limited by desired observation begin and end time,
// and expressed in Date
Date bodyObsEnd = new Date(context.JulianDayMidnight + endTime, context.GeoLocation.UtcOffset);
bodyEphemerides.Add(new Ephemeris("Observation.Begin", bodyObsBegin, Formatters.Time));
bodyEphemerides.Add(new Ephemeris("Observation.Duration", bodyObsDuration, Formatters.VisibilityDuration));
bodyEphemerides.Add(new Ephemeris("Observation.End", bodyObsEnd, Formatters.Time));
// best time of observation (in the expected time range)
{
var transit = visibilityEphems.GetValue <Date>("RTS.Transit");
var transitAlt = visibilityEphems.GetValue <double>("RTS.TransitAltitude");
AngleRange bodyObsRange = new AngleRange(bodyObsBegin.Time * 360, bodyObsDuration / 24 * 360);
AngleRange tranRange = new AngleRange(transit.Time * 360, 1e-6);
if (bodyObsRange.Overlaps(tranRange).Any())
{
bodyEphemerides.Add(new Ephemeris("Observation.Best", transit, Formatters.Time));
bodyEphemerides.Add(new Ephemeris("Observation.BestAltitude", transitAlt, Formatters.Altitude));
bodyEphemerides.Add(new Ephemeris("Observation.BestAzimuth", 0.0, Formatters.Azimuth));
var ctxBest = new SkyContext(transit.ToJulianEphemerisDay(), context.GeoLocation, preferFast: true);
var bestEphemerides = sky.GetEphemerides(body, ctxBest, new[] { "Equatorial.Alpha", "Equatorial.Delta", "Constellation" });
bodyEphemerides.AddRange(bestEphemerides);
}
else
{
var ctxBegin = new SkyContext(bodyObsBegin.ToJulianEphemerisDay(), context.GeoLocation, preferFast: true);
var beginEphemerides = sky.GetEphemerides(body, ctxBegin, new[] { "Horizontal.Altitude", "Horizontal.Azimuth", "Equatorial.Alpha", "Equatorial.Delta", "Constellation" });
double altBegin = beginEphemerides.GetValue <double>("Horizontal.Altitude");
double aziBegin = beginEphemerides.GetValue <double>("Horizontal.Azimuth");
var ctxEnd = new SkyContext(bodyObsEnd.ToJulianEphemerisDay(), context.GeoLocation, preferFast: true);
var endEphemerides = sky.GetEphemerides(body, ctxEnd, new[] { "Horizontal.Altitude", "Horizontal.Azimuth", "Equatorial.Alpha", "Equatorial.Delta", "Constellation" });
double altEnd = endEphemerides.GetValue <double>("Horizontal.Altitude");
double aziEnd = endEphemerides.GetValue <double>("Horizontal.Azimuth");
if (altBegin >= altEnd)
{
bodyEphemerides.Add(new Ephemeris("Observation.Best", bodyObsBegin, Formatters.Time));
bodyEphemerides.Add(new Ephemeris("Observation.BestAltitude", altBegin, Formatters.Altitude));
bodyEphemerides.Add(new Ephemeris("Observation.BestAzimuth", aziBegin, Formatters.Azimuth));
bodyEphemerides.AddRange(beginEphemerides);
}
else
{
bodyEphemerides.Add(new Ephemeris("Observation.Best", bodyObsEnd, Formatters.Time));
bodyEphemerides.Add(new Ephemeris("Observation.BestAltitude", altEnd, Formatters.Altitude));
bodyEphemerides.Add(new Ephemeris("Observation.BestAzimuth", aziEnd, Formatters.Azimuth));
bodyEphemerides.AddRange(endEphemerides);
}
}
}
return(bodyEphemerides);
}
}
}
// body observation duration does not match with desired time
// or body does not observable at all,
// or no info provided about observation
if (force)
{
bodyEphemerides.Add(new Ephemeris("Observation.Begin", new Date(double.NaN), Formatters.Time));
bodyEphemerides.Add(new Ephemeris("Observation.Duration", double.NaN, Formatters.VisibilityDuration));
bodyEphemerides.Add(new Ephemeris("Observation.End", new Date(double.NaN), Formatters.Time));
bodyEphemerides.Add(new Ephemeris("Observation.Best", new Date(double.NaN), Formatters.Time));
bodyEphemerides.Add(new Ephemeris("Observation.BestAltitude", double.NaN, Formatters.Altitude));
bodyEphemerides.Add(new Ephemeris("Observation.BestAzimuth", double.NaN, Formatters.Azimuth));
bodyEphemerides.AddRange(visibilityEphems);
var ctx = new SkyContext(filter.JulianDayMidnight, filter.ObserverLocation, preferFast: true);
bodyEphemerides.AddRange(sky.GetEphemerides(body, ctx, new[] { "Horizontal.Altitude", "Horizontal.Azimuth", "Equatorial.Alpha", "Equatorial.Delta", "Constellation" }));
// final check: add fictive/empty ephemerides as it needed by planner
AddEphemIfMissing(bodyEphemerides, "Constellation", null);
AddEphemIfMissing(bodyEphemerides, "Equatorial.Alpha", double.NaN);
AddEphemIfMissing(bodyEphemerides, "Equatorial.Delta", double.NaN);
AddEphemIfMissing(bodyEphemerides, "Horizontal.Altitude", double.NaN);
AddEphemIfMissing(bodyEphemerides, "Horizontal.Azimuth", double.NaN);
AddEphemIfMissing(bodyEphemerides, "Constellation", null);
AddEphemIfMissing(bodyEphemerides, "RTS.RiseAzimuth", double.NaN);
AddEphemIfMissing(bodyEphemerides, "RTS.SetAzimuth", double.NaN);
AddEphemIfMissing(bodyEphemerides, "RTS.TransitAltitude", double.NaN);
return(bodyEphemerides);
}
return(null);
}
