v2: Satellite passes !24

merged merged by cmc on 2026-10-18 08:45 UTC · krz/moonrise:v2-satellites into main

9 files changed, +517 −1

Layout: unified · split

App/Sources/SkyModel.swift +20

	@@ -51,6 +51,9 @@ final class SkyModel: NSObject, CLLocationManagerDelegate {
51	private(set) var lastBuild: Duration = .zero	51	private(set) var lastBuild: Duration = .zero
52	private(set) var tonight: Tonight?	52	private(set) var tonight: Tonight?
53	private(set) var spaceWeather: SpaceWeather?	53	private(set) var spaceWeather: SpaceWeather?
		54	private(set) var passes: [SatellitePass] = []
		55	private var elements: [OrbitalElements] = []
		56	private var elementsFetched: Date?
54	private var weatherFetched: Date?	57	private var weatherFetched: Date?
55	/// Hours from now shown by the time scrubber.	58	/// Hours from now shown by the time scrubber.
56	var offsetHours = 0.0 { didSet { refresh() } }	59	var offsetHours = 0.0 { didSet { refresh() } }
	@@ -109,6 +112,23 @@ final class SkyModel: NSObject, CLLocationManagerDelegate {
109	}	112	}
110	}	113	}
111		114
		115	private struct SatelliteList: Decodable { var satellites: [OrbitalElements] }
		116
		117	/// Orbital elements from the backend (refreshed hourly), then passes for the next three days.
		118	func refreshPasses() async {
		119	if elementsFetched.map({ Date.now.timeIntervalSince($0) > 3600 }) ?? true, let apiBase {
		120	if let (data, _) = try? await URLSession.shared.data(from: apiBase.appending(path: "v1/satellites")),
		121	let list = try? JSONDecoder().decode(SatelliteList.self, from: data), !list.satellites.isEmpty {
		122	elements = list.satellites
		123	elementsFetched = .now
		124	}
		125	}
		126	let elements = elements, observer = observer
		127	passes = await Task.detached {
		128	elements.flatMap { SkyEngine.passes(of: $0, from: .now, hours: 72, observer: observer) }.sorted { $0.rise < $1.rise }
		129	}.value
		130	}
		131
112	/// SWPC asks for no more than once a minute; this checks every 10.	132	/// SWPC asks for no more than once a minute; this checks every 10.
113	func refreshSpaceWeather() async {	133	func refreshSpaceWeather() async {
114	if let weatherFetched, Date.now.timeIntervalSince(weatherFetched) < 600 { return }	134	if let weatherFetched, Date.now.timeIntervalSince(weatherFetched) < 600 { return }

App/Sources/TodaySheet.swift +28

	@@ -16,6 +16,7 @@ struct TodaySheet: View {
16	section("Planets tonight") { planets(t) }	16	section("Planets tonight") { planets(t) }
17	section("Sun") { sun(t) }	17	section("Sun") { sun(t) }
18	}	18	}
		19	section("Satellite passes") { satellites }
19	section("Space weather") { weather }	20	section("Space weather") { weather }
20	Text("Space weather data: NOAA Space Weather Prediction Center.")	21	Text("Space weather data: NOAA Space Weather Prediction Center.")
21	.font(.caption2).dimmed(0.5).padding(.top, 8)	22	.font(.caption2).dimmed(0.5).padding(.top, 8)
	@@ -25,6 +26,7 @@ struct TodaySheet: View {
25	}	26	}
26	.foregroundStyle(ink)	27	.foregroundStyle(ink)
27	.presentationBackground(background)	28	.presentationBackground(background)
		29	.task { await model.refreshPasses() }
28	}	30	}
29		31
30	private func section(_ title: String, @ViewBuilder content: () -> some View) -> some View {	32	private func section(_ title: String, @ViewBuilder content: () -> some View) -> some View {
	@@ -77,6 +79,32 @@ struct TodaySheet: View {
77	])	79	])
78	}	80	}
79		81
		82	@ViewBuilder
		83	private var satellites: some View {
		84	let shown = model.passes.prefix(8)
		85	if shown.isEmpty {
		86	Text("No passes above 10° in the next three days.").font(.subheadline).dimmed(0.6)
		87	} else {
		88	VStack(alignment: .leading, spacing: 10) {
		89	ForEach(Array(shown)) { p in
		90	VStack(alignment: .leading, spacing: 2) {
		91	HStack {
		92	Text(p.name.replacingOccurrences(of: " (ZARYA)", with: "")).font(.subheadline.weight(.medium))
		93	if p.visible {
		94	Text("Visible").font(.caption2.weight(.medium)).padding(.horizontal, 5).padding(.vertical, 1)
		95	.overlay(RoundedRectangle(cornerRadius: 3).stroke(lineWidth: 1))
		96	}
		97	}
		98	Text(p.rise.formatted(.dateTime.weekday(.abbreviated).hour().minute()) + String(format: " · rises %@, highest %.0f°, sets %@", compass(p.riseAzimuth), p.maxAltitude, compass(p.setAzimuth)))
		99	.font(.footnote.monospacedDigit()).dimmed(0.8)
		100	}
		101	.accessibilityElement(children: .combine)
		102	}
		103	Text("Visible means sunlit while your sky is dark. Orbits: CelesTrak.").font(.caption2).dimmed(0.6)
		104	}
		105	}
		106	}
		107
80	@ViewBuilder	108	@ViewBuilder
81	private var weather: some View {	109	private var weather: some View {
82	if let w = model.spaceWeather {	110	if let w = model.spaceWeather {

Packages/MoonriseKit/Sources/SkyEngine/Passes.swift added +103

@@ -0,0 +1,103 @@
	1	import CAstronomy
	2	import Foundation
	3
	4	public struct SatellitePass: Sendable, Identifiable, Equatable {
	5	public var name: String
	6	public var rise: Date
	7	public var set: Date
	8	public var peak: Date
	9	public var maxAltitude: Double
	10	public var riseAzimuth: Double
	11	public var setAzimuth: Double
	12	/// Sunlit while the observer's sky is dark: can be seen with the eye.
	13	public var visible: Bool
	14	public var id: String { "\(name)-\(Int(rise.timeIntervalSince1970))" }
	15	}
	16
	17	extension SkyEngine {
	18	/// Greenwich mean sidereal time in radians (IAU 1982, as used with SGP4's TEME frame).
	19	static func gmst(_ date: Date) -> Double {
	20	let jd = date.timeIntervalSince1970 / 86_400 + 2_440_587.5
	21	let t = (jd - 2_451_545) / 36_525
	22	var s = -6.2e-6 * t * t * t + 0.093104 * t * t + (876_600 * 3600 + 8_640_184.812866) * t + 67_310.54841
	23	s = fmod(s * Double.pi / 180 / 240, 2 * Double.pi)
	24	return s < 0 ? s + 2 * Double.pi : s
	25	}
	26
	27	/// Observer position in an Earth-fixed frame (km), WGS-84.
	28	static func observerECEF(_ o: Observer) -> SIMD3<Double> {
	29	let a = 6378.137, f = 1 / 298.257223563
	30	let e2 = f * (2 - f)
	31	let lat = o.latitude * .pi / 180, lon = o.longitude * .pi / 180, h = o.height / 1000
	32	let n = a / (1 - e2 * sin(lat) * sin(lat)).squareRoot()
	33	return SIMD3((n + h) * cos(lat) * cos(lon), (n + h) * cos(lat) * sin(lon), (n * (1 - e2) + h) * sin(lat))
	34	}
	35
	36	/// Altitude and azimuth of a TEME position as seen by the observer.
	37	static func lookAngles(teme r: SIMD3<Double>, at date: Date, from o: Observer) -> Horizontal {
	38	let g = gmst(date)
	39	let ecef = SIMD3(r.x * cos(g) + r.y * sin(g), -r.x * sin(g) + r.y * cos(g), r.z)
	40	let d = ecef - observerECEF(o)
	41	let lat = o.latitude * .pi / 180, lon = o.longitude * .pi / 180
	42	let south = sin(lat) * cos(lon) * d.x + sin(lat) * sin(lon) * d.y - cos(lat) * d.z
	43	let east = -sin(lon) * d.x + cos(lon) * d.y
	44	let up = cos(lat) * cos(lon) * d.x + cos(lat) * sin(lon) * d.y + sin(lat) * d.z
	45	let range = (d * d).sum().squareRoot()
	46	var az = atan2(east, -south) * 180 / .pi
	47	if az < 0 { az += 360 }
	48	return Horizontal(altitude: asin(up / range) * 180 / .pi, azimuth: az)
	49	}
	50
	51	/// Unit vector to the Sun on equator-of-date axes, close enough to TEME for Earth's shadow.
	52	static func sunDirection(_ date: Date) -> SIMD3<Double> {
	53	var t = time(date)
	54	let v = Astronomy_GeoVector(BODY_SUN, t, NO_ABERRATION)
	55	let rot = Astronomy_Rotation_EQJ_EQD(&t)
	56	let e = Astronomy_RotateVector(rot, v)
	57	let s = SIMD3(e.x, e.y, e.z)
	58	return s / (s * s).sum().squareRoot()
	59	}
	60
	61	/// Cylindrical Earth-shadow test.
	62	static func sunlit(_ r: SIMD3<Double>, sun: SIMD3<Double>) -> Bool {
	63	let along = (r * sun).sum()
	64	if along > 0 { return true }
	65	let perp = r - along * sun
	66	return (perp * perp).sum().squareRoot() > 6378.135
	67	}
	68
	69	/// Passes above `minAltitude` in the next `hours`, sampled every 20 s.
	70	public static func passes(of elements: OrbitalElements, from start: Date, hours: Double = 72, observer: Observer, minAltitude: Double = 10) -> [SatellitePass] {
	71	guard let sgp = try? SGP4(elements) else { return [] }
	72	lock.lock()
	73	defer { lock.unlock() }
	74	var out: [SatellitePass] = []
	75	var current: (rise: Date, riseAz: Double, peak: Date, maxAlt: Double, visible: Bool)?
	76	var lastAz = 0.0
	77	let step = 20.0
	78	var t = start
	79	let end = start.addingTimeInterval(hours * 3600)
	80	while t <= end {
	81	guard let r = sgp.position(at: t) else { break }
	82	let h = lookAngles(teme: r, at: t, from: observer)
	83	if h.altitude >= 0 {
	84	if current == nil { current = (t, h.azimuth, t, h.altitude, false) }
	85	if h.altitude > current!.maxAlt { current!.maxAlt = h.altitude; current!.peak = t }
	86	if !current!.visible, h.altitude >= minAltitude {
	87	var tt = time(t)
	88	let sun = Astronomy_Equator(BODY_SUN, &tt, observer.astro, EQUATOR_OF_DATE, ABERRATION)
	89	let sunAlt = Astronomy_Horizon(&tt, observer.astro, sun.ra, sun.dec, REFRACTION_NORMAL).altitude
	90	if sunAlt < -6, sunlit(r, sun: sunDirection(t)) { current!.visible = true }
	91	}
	92	lastAz = h.azimuth
	93	} else if let c = current {
	94	if c.maxAlt >= minAltitude {
	95	out.append(SatellitePass(name: elements.OBJECT_NAME, rise: c.rise, set: t, peak: c.peak, maxAltitude: c.maxAlt, riseAzimuth: c.riseAz, setAzimuth: lastAz, visible: c.visible))
	96	}
	97	current = nil
	98	}
	99	t = t.addingTimeInterval(step)
	100	}
	101	return out
	102	}
	103	}

Packages/MoonriseKit/Sources/SkyEngine/SGP4.swift added +232

@@ -0,0 +1,232 @@
	1	import Foundation
	2
	3	/// General perturbations orbital elements in CelesTrak's OMM JSON form.
	4	public struct OrbitalElements: Codable, Sendable, Hashable {
	5	public var OBJECT_NAME: String
	6	public var NORAD_CAT_ID: Int
	7	/// UTC, ISO 8601 without a zone, e.g. "2026-10-18T03:28:15.076416".
	8	public var EPOCH: String
	9	/// Revolutions per day.
	10	public var MEAN_MOTION: Double
	11	public var ECCENTRICITY: Double
	12	/// Degrees.
	13	public var INCLINATION: Double
	14	public var RA_OF_ASC_NODE: Double
	15	public var ARG_OF_PERICENTER: Double
	16	public var MEAN_ANOMALY: Double
	17	public var BSTAR: Double
	18
	19	public init(name: String, norad: Int, epoch: String, meanMotion: Double, eccentricity: Double, inclination: Double, raan: Double, argPerigee: Double, meanAnomaly: Double, bstar: Double) {
	20	OBJECT_NAME = name; NORAD_CAT_ID = norad; EPOCH = epoch; MEAN_MOTION = meanMotion; ECCENTRICITY = eccentricity
	21	INCLINATION = inclination; RA_OF_ASC_NODE = raan; ARG_OF_PERICENTER = argPerigee; MEAN_ANOMALY = meanAnomaly; BSTAR = bstar
	22	}
	23
	24	public var epochDate: Date? {
	25	let parts = EPOCH.split(separator: ".")
	26	guard let whole = try? Date(String(parts[0]) + "Z", strategy: .iso8601) else { return nil }
	27	let frac = parts.count > 1 ? Double("0." + parts[1]) ?? 0 : 0
	28	return whole.addingTimeInterval(frac)
	29	}
	30	}
	31
	32	/// Near-Earth SGP4 (Vallado et al. 2006, "Revisiting Spacetrack Report #3"), WGS-72 constants.
	33	/// Deep-space orbits (period of 225 minutes or more) are not supported.
	34	public struct SGP4: Sendable {
	35	// WGS-72
	36	static let mu = 398600.8
	37	static let re = 6378.135
	38	static let xke = 60.0 / ((re * re * re) / mu).squareRoot()
	39	static let j2 = 0.001082616
	40	static let j3 = -0.00000253881
	41	static let j4 = -0.00000165597
	42	static let j3oj2 = j3 / j2
	43	static let twoPi = 2 * Double.pi
	44
	45	public let epoch: Date
	46	let ecco, inclo, nodeo, argpo, mo, bstar: Double
	47	let noUnkozai, ao, con41, x1mth2, x7thm1, eta, cc1, cc4, cc5, d2, d3, d4, t2cof, t3cof, t4cof, t5cof: Double
	48	let mdot, argpdot, nodedot, nodecf, omgcof, xmcof, xlcof, aycof, delmo, sinmao, cosio, sinio: Double
	49	let isimp: Bool
	50
	51	public enum Failure: Error { case deepSpace, badEpoch }
	52
	53	public init(_ el: OrbitalElements) throws {
	54	guard let epoch = el.epochDate else { throw Failure.badEpoch }
	55	self.epoch = epoch
	56	let r = Double.pi / 180
	57	ecco = el.ECCENTRICITY
	58	inclo = el.INCLINATION * r
	59	nodeo = el.RA_OF_ASC_NODE * r
	60	argpo = el.ARG_OF_PERICENTER * r
	61	mo = el.MEAN_ANOMALY * r
	62	bstar = el.BSTAR
	63	let noKozai = el.MEAN_MOTION * Self.twoPi / 1440
	64	let x2o3 = 2.0 / 3.0
	65
	66	// initl
	67	let eccsq = ecco * ecco, omeosq = 1 - eccsq, rteosq = omeosq.squareRoot()
	68	cosio = cos(inclo)
	69	let cosio2 = cosio * cosio
	70	let ak = pow(Self.xke / noKozai, x2o3)
	71	let d1 = 0.75 * Self.j2 * (3 * cosio2 - 1) / (rteosq * omeosq)
	72	var del = d1 / (ak * ak)
	73	let adel = ak * (1 - del * del - del * (1.0 / 3.0 + 134 * del * del / 81))
	74	del = d1 / (adel * adel)
	75	noUnkozai = noKozai / (1 + del)
	76	guard Self.twoPi / noUnkozai < 225 else { throw Failure.deepSpace }
	77	ao = pow(Self.xke / noUnkozai, x2o3)
	78	sinio = sin(inclo)
	79	let po = ao * omeosq
	80	let con42 = 1 - 5 * cosio2
	81	con41 = -con42 - cosio2 - cosio2
	82	let posq = po * po
	83	let rp = ao * (1 - ecco)
	84
	85	// sgp4init
	86	let ss = 78 / Self.re + 1
	87	let qzms2t = pow((120 - 78) / Self.re, 4)
	88	isimp = rp < 220 / Self.re + 1
	89	var sfour = ss, qzms24 = qzms2t
	90	let perige = (rp - 1) * Self.re
	91	if perige < 156 {
	92	sfour = perige < 98 ? 20 : perige - 78
	93	qzms24 = pow((120 - sfour) / Self.re, 4)
	94	sfour = sfour / Self.re + 1
	95	}
	96	let pinvsq = 1 / posq
	97	let tsi = 1 / (ao - sfour)
	98	eta = ao * ecco * tsi
	99	let etasq = eta * eta, eeta = ecco * eta
	100	let psisq = abs(1 - etasq)
	101	let coef = qzms24 * pow(tsi, 4)
	102	let coef1 = coef / pow(psisq, 3.5)
	103	let cc2 = coef1 * noUnkozai * (ao * (1 + 1.5 * etasq + eeta * (4 + etasq)) + 0.375 * Self.j2 * tsi / psisq * con41 * (8 + 3 * etasq * (8 + etasq)))
	104	cc1 = bstar * cc2
	105	let cc3 = ecco > 1e-4 ? -2 * coef * tsi * Self.j3oj2 * noUnkozai * sinio / ecco : 0
	106	x1mth2 = 1 - cosio2
	107	cc4 = 2 * noUnkozai * coef1 * ao * omeosq * (eta * (2 + 0.5 * etasq) + ecco * (0.5 + 2 * etasq)
	108	- Self.j2 * tsi / (ao * psisq) * (-3 * con41 * (1 - 2 * eeta + etasq * (1.5 - 0.5 * eeta)) + 0.75 * x1mth2 * (2 * etasq - eeta * (1 + etasq)) * cos(2 * argpo)))
	109	cc5 = 2 * coef1 * ao * omeosq * (1 + 2.75 * (etasq + eeta) + eeta * etasq)
	110	let cosio4 = cosio2 * cosio2
	111	let temp1 = 1.5 * Self.j2 * pinvsq * noUnkozai
	112	let temp2 = 0.5 * temp1 * Self.j2 * pinvsq
	113	let temp3 = -0.46875 * Self.j4 * pinvsq * pinvsq * noUnkozai
	114	mdot = noUnkozai + 0.5 * temp1 * rteosq * con41 + 0.0625 * temp2 * rteosq * (13 - 78 * cosio2 + 137 * cosio4)
	115	argpdot = -0.5 * temp1 * con42 + 0.0625 * temp2 * (7 - 114 * cosio2 + 395 * cosio4) + temp3 * (3 - 36 * cosio2 + 49 * cosio4)
	116	let xhdot1 = -temp1 * cosio
	117	nodedot = xhdot1 + (0.5 * temp2 * (4 - 19 * cosio2) + 2 * temp3 * (3 - 7 * cosio2)) * cosio
	118	omgcof = bstar * cc3 * cos(argpo)
	119	xmcof = ecco > 1e-4 ? -x2o3 * coef * bstar / eeta : 0
	120	nodecf = 3.5 * omeosq * xhdot1 * cc1
	121	t2cof = 1.5 * cc1
	122	xlcof = -0.25 * Self.j3oj2 * sinio * (3 + 5 * cosio) / (abs(cosio + 1) > 1.5e-12 ? 1 + cosio : 1.5e-12)
	123	aycof = -0.5 * Self.j3oj2 * sinio
	124	delmo = pow(1 + eta * cos(mo), 3)
	125	sinmao = sin(mo)
	126	x7thm1 = 7 * cosio2 - 1
	127	if !isimp {
	128	let cc1sq = cc1 * cc1
	129	d2 = 4 * ao * tsi * cc1sq
	130	let temp = d2 * tsi * cc1 / 3
	131	d3 = (17 * ao + sfour) * temp
	132	d4 = 0.5 * temp * ao * tsi * (221 * ao + 31 * sfour) * cc1
	133	t3cof = d2 + 2 * cc1sq
	134	t4cof = 0.25 * (3 * d3 + cc1 * (12 * d2 + 10 * cc1sq))
	135	t5cof = 0.2 * (3 * d4 + 12 * cc1 * d3 + 6 * d2 * d2 + 15 * cc1sq * (2 * d2 + cc1sq))
	136	} else {
	137	d2 = 0; d3 = 0; d4 = 0; t3cof = 0; t4cof = 0; t5cof = 0
	138	}
	139	}
	140
	141	/// Position (km) and velocity (km/s) in the TEME frame, `minutes` after epoch.
	142	public func propagate(minutes t: Double) -> (r: SIMD3<Double>, v: SIMD3<Double>)? {
	143	let x2o3 = 2.0 / 3.0
	144	let xmdf = mo + mdot * t
	145	let argpdf = argpo + argpdot * t
	146	let nodedf = nodeo + nodedot * t
	147	var argpm = argpdf, mm = xmdf
	148	let t2 = t * t
	149	var nodem = nodedf + nodecf * t2
	150	var tempa = 1 - cc1 * t
	151	var tempe = bstar * cc4 * t
	152	var templ = t2cof * t2
	153	if !isimp {
	154	let delomg = omgcof * t
	155	let delm = xmcof * (pow(1 + eta * cos(xmdf), 3) - delmo)
	156	let temp = delomg + delm
	157	mm = xmdf + temp
	158	argpm = argpdf - temp
	159	let t3 = t2 * t, t4 = t3 * t
	160	tempa = tempa - d2 * t2 - d3 * t3 - d4 * t4
	161	tempe = tempe + bstar * cc5 * (sin(mm) - sinmao)
	162	templ = templ + t3cof * t3 + t4 * (t4cof + t * t5cof)
	163	}
	164	let am = pow(Self.xke / noUnkozai, x2o3) * tempa * tempa
	165	let nm = Self.xke / pow(am, 1.5)
	166	var em = ecco - tempe
	167	guard em < 1, am >= 0.95 else { return nil }
	168	if em < 1e-6 { em = 1e-6 }
	169	mm += noUnkozai * templ
	170	var xlm = mm + argpm + nodem
	171	nodem = fmod(nodem, Self.twoPi)
	172	argpm = fmod(argpm, Self.twoPi)
	173	xlm = fmod(xlm, Self.twoPi)
	174	mm = fmod(xlm - argpm - nodem, Self.twoPi)
	175
	176	// Long-period periodics
	177	let axnl = em * cos(argpm)
	178	var temp = 1 / (am * (1 - em * em))
	179	let aynl = em * sin(argpm) + temp * aycof
	180	let xl = mm + argpm + nodem + temp * xlcof * axnl
	181
	182	// Kepler's equation
	183	let u = fmod(xl - nodem, Self.twoPi)
	184	var eo1 = u, tem5 = 9999.9, ktr = 1
	185	var sineo1 = 0.0, coseo1 = 0.0
	186	while abs(tem5) >= 1e-12 && ktr <= 10 {
	187	sineo1 = sin(eo1); coseo1 = cos(eo1)
	188	tem5 = 1 - coseo1 * axnl - sineo1 * aynl
	189	tem5 = (u - aynl * coseo1 + axnl * sineo1 - eo1) / tem5
	190	if abs(tem5) >= 0.95 { tem5 = tem5 > 0 ? 0.95 : -0.95 }
	191	eo1 += tem5
	192	ktr += 1
	193	}
	194
	195	// Short-period periodics
	196	let ecose = axnl * coseo1 + aynl * sineo1
	197	let esine = axnl * sineo1 - aynl * coseo1
	198	let el2 = axnl * axnl + aynl * aynl
	199	let pl = am * (1 - el2)
	200	guard pl >= 0 else { return nil }
	201	let rl = am * (1 - ecose)
	202	let rdotl = am.squareRoot() * esine / rl
	203	let rvdotl = pl.squareRoot() / rl
	204	let betal = (1 - el2).squareRoot()
	205	temp = esine / (1 + betal)
	206	let sinu = am / rl * (sineo1 - aynl - axnl * temp)
	207	let cosu = am / rl * (coseo1 - axnl + aynl * temp)
	208	var su = atan2(sinu, cosu)
	209	let sin2u = (cosu + cosu) * sinu
	210	let cos2u = 1 - 2 * sinu * sinu
	211	temp = 1 / pl
	212	let temp1 = 0.5 * Self.j2 * temp
	213	let temp2 = temp1 * temp
	214	let mrt = rl * (1 - 1.5 * temp2 * betal * con41) + 0.5 * temp1 * x1mth2 * cos2u
	215	su -= 0.25 * temp2 * x7thm1 * sin2u
	216	let xnode = nodem + 1.5 * temp2 * cosio * sin2u
	217	let xinc = inclo + 1.5 * temp2 * cosio * sinio * cos2u
	218	let mvt = rdotl - nm * temp1 * x1mth2 * sin2u / Self.xke
	219	let rvdot = rvdotl + nm * temp1 * (x1mth2 * cos2u + 1.5 * con41) / Self.xke
	220
	221	let sinsu = sin(su), cossu = cos(su), snod = sin(xnode), cnod = cos(xnode), sini = sin(xinc), cosi = cos(xinc)
	222	let xmx = -snod * cosi, xmy = cnod * cosi
	223	let uv = SIMD3(xmx * sinsu + cnod * cossu, xmy * sinsu + snod * cossu, sini * sinsu)
	224	let vv = SIMD3(xmx * cossu - cnod * sinsu, xmy * cossu - snod * sinsu, sini * cossu)
	225	let vkmpersec = Self.re * Self.xke / 60
	226	return (mrt * uv * Self.re, (mvt * uv + rvdot * vv) * vkmpersec)
	227	}
	228
	229	public func position(at date: Date) -> SIMD3<Double>? {
	230	propagate(minutes: date.timeIntervalSince(epoch) / 60)?.r
	231	}
	232	}

Packages/MoonriseKit/Tests/SkyEngineTests/SGP4Tests.swift added +62

@@ -0,0 +1,62 @@
	1	import Foundation
	2	import Testing
	3	@testable import SkyEngine
	4
	5	// Vallado's SGP4 verification case for satellite 00005 (SGP4-VER.TLE / tcppver.out):
	6	// 1 00005U 58002B 00179.78495062 .00000023 00000-0 28098-4 0 4753
	7	// 2 00005 34.2682 348.7242 1859667 331.7664 19.3264 10.82419157413667
	8	// Epoch 2000 day 179.78495062 = 2000-06-27T18:50:19.733568Z.
	9	let vanguard = OrbitalElements(name: "00005", norad: 5, epoch: "2000-06-27T18:50:19.733568",
	10	meanMotion: 10.82419157, eccentricity: 0.1859667, inclination: 34.2682,
	11	raan: 348.7242, argPerigee: 331.7664, meanAnomaly: 19.3264, bstar: 0.28098e-4)
	12
	13	func dist(_ a: SIMD3<Double>, _ b: SIMD3<Double>) -> Double { let d = a - b; return (d * d).sum().squareRoot() }
	14
	15	@Test(arguments: [
	16	(0.0, SIMD3(7022.46529266, -1400.08296755, 0.03995155), SIMD3(1.893841015, 6.405893759, 4.534807250)),
	17	(360.0, SIMD3(-7154.03120202, -3783.17682504, -3536.19412294), SIMD3(4.741887409, -4.151817765, -2.093935425)),
	18	(720.0, SIMD3(-7134.59340119, 6531.68641334, 3260.27186483), SIMD3(-4.113793027, -2.911922039, -2.557327851)),
	19	])
	20	func matchesValladoVerification(_ t: Double, _ r: SIMD3<Double>, _ v: SIMD3<Double>) throws {
	21	let s = try SGP4(vanguard)
	22	let out = try #require(s.propagate(minutes: t))
	23	#expect(dist(out.r, r) < 0.01, "t=\(t): r off by \(dist(out.r, r)) km")
	24	#expect(dist(out.v, v) < 1e-5, "t=\(t): v off by \(dist(out.v, v)) km/s")
	25	}
	26
	27	@Test func epochParsesFractionalSeconds() throws {
	28	let d = try #require(vanguard.epochDate)
	29	#expect(abs(d.timeIntervalSince1970 - 962_131_819.733568) < 1e-3)
	30	}
	31
	32	@Test func issIsInLowOrbit() throws {
	33	// CelesTrak GP for the ISS, 2026-10-18.
	34	let iss = OrbitalElements(name: "ISS (ZARYA)", norad: 25544, epoch: "2026-10-18T03:28:15.076416",
	35	meanMotion: 15.48918166, eccentricity: 0.000678, inclination: 51.6328,
	36	raan: 51.6259, argPerigee: 277.7856, meanAnomaly: 82.2363, bstar: 0.00014456)
	37	let s = try SGP4(iss)
	38	let r = try #require(s.propagate(minutes: 60)?.r)
	39	let altitude = (r * r).sum().squareRoot() - 6378.135
	40	#expect(altitude > 380 && altitude < 450, "\(altitude) km")
	41	}
	42
	43	@Test func gmstAtJ2000() {
	44	// GMST at 2000-01-01 12:00 UT1 is 280.46061837 degrees.
	45	let g = SkyEngine.gmst(Date(timeIntervalSince1970: 946_728_000)) * 180 / .pi
	46	#expect(abs(g - 280.46061837) < 1e-4)
	47	}
	48
	49	@Test func issPassesOverChicago() throws {
	50	let iss = OrbitalElements(name: "ISS (ZARYA)", norad: 25544, epoch: "2026-10-18T03:28:15.076416",
	51	meanMotion: 15.48918166, eccentricity: 0.000678, inclination: 51.6328,
	52	raan: 51.6259, argPerigee: 277.7856, meanAnomaly: 82.2363, bstar: 0.00014456)
	53	let start = try #require(iss.epochDate)
	54	let passes = SkyEngine.passes(of: iss, from: start, hours: 72, observer: chicago)
	55	// The ISS (51.6° inclination) passes over 42° N several times a day.
	56	#expect(passes.count >= 6, "\(passes.count) passes")
	57	for p in passes {
	58	#expect(p.maxAltitude >= 10 && p.maxAltitude <= 90)
	59	let minutes = p.set.timeIntervalSince(p.rise) / 60
	60	#expect(minutes > 2 && minutes < 12, "\(minutes) min")
	61	}
	62	}

server/src/celestrak.ts added +37

@@ -0,0 +1,37 @@
	1	// CelesTrak GP data. CelesTrak updates every 2 hours and blocks IPs that fetch more
	2	// often or keep requesting after errors, so poll every 2 hours and stop on any non-200.
	3
	4	/** ISS, Tiangong (CSS Tianhe) and Hubble. */
	5	export const SATELLITES = [25544, 48274, 20580];
	6
	7	export interface OMM {
	8	OBJECT_NAME: string;
	9	NORAD_CAT_ID: number;
	10	EPOCH: string;
	11	MEAN_MOTION: number;
	12	ECCENTRICITY: number;
	13	INCLINATION: number;
	14	RA_OF_ASC_NODE: number;
	15	ARG_OF_PERICENTER: number;
	16	MEAN_ANOMALY: number;
	17	BSTAR: number;
	18	}
	19
	20	const KEYS: (keyof OMM)[] = ["OBJECT_NAME", "NORAD_CAT_ID", "EPOCH", "MEAN_MOTION", "ECCENTRICITY", "INCLINATION", "RA_OF_ASC_NODE", "ARG_OF_PERICENTER", "MEAN_ANOMALY", "BSTAR"];
	21
	22	export function pick(rows: Record<string, unknown>[]): OMM[] {
	23	return rows.map((r) => Object.fromEntries(KEYS.map((k) => [k, r[k]])) as unknown as OMM);
	24	}
	25
	26	/** Fetches each satellite in turn; throws on the first non-200 so nothing more is requested. */
	27	export async function fetchElements(): Promise<OMM[]> {
	28	const out: OMM[] = [];
	29	for (const id of SATELLITES) {
	30	const res = await fetch(`https://celestrak.org/NORAD/elements/gp.php?CATNR=${id}&FORMAT=JSON`, {
	31	headers: { "user-agent": "moonrise-server (sh.krz.moonrise)" },
	32	});
	33	if (res.status !== 200) throw new Error(`CelesTrak ${res.status} for ${id}`);
	34	out.push(...pick((await res.json()) as Record<string, unknown>[]));
	35	}
	36	return out;
	37	}

server/src/index.ts +18

 import { send, type ApnsConfig } from "./apns";
 import { actionableKp, alertBands, eventKey, isNight } from "./aurora";
+import { fetchElements } from "./celestrak";
 import { fetchUpcoming, type Launch } from "./ll2";
 import { PRIVACY_HTML } from "./privacy";
 import { fetchSpaceWeather, next24h, type SpaceWeather } from "./swpc";
 }
 const LAUNCH_CRON = "*/10 * * * *";
+const SATELLITE_CRON = "7 */2 * * *";
 const json = (body: unknown, status = 200) => Response.json(body, { status });
       return new Response(PRIVACY_HTML, { headers: { "content-type": "text/html; charset=utf-8", "cache-control": "public, max-age=3600" } });
     if (request.method === "GET" && url.pathname === "/v1/today") return today(env, now);
     if (request.method === "GET" && url.pathname === "/v1/launches") return launches(env, now);
+    if (request.method === "GET" && url.pathname === "/v1/satellites") {
+      const row = await env.DB.prepare("SELECT fetched_at, body FROM feed_snapshots WHERE feed = 'celestrak' AND ok = 1").first<{ fetched_at: string; body: string }>();
+      return json({ fetchedAt: row?.fetched_at ?? null, satellites: row ? JSON.parse(row.body) : [] });
+    }
     if (request.method === "POST" && url.pathname === "/v1/devices") {
       const d = (await request.json().catch(() => ({}))) as Partial<DeviceRequest>;
     const now = new Date(controller.scheduledTime);
     // Launches every 10 minutes: 6 of the 15 anonymous Launch Library 2 requests per hour.
     if (controller.cron === LAUNCH_CRON) ctx.waitUntil(pollLaunches(env, now));
+    else if (controller.cron === SATELLITE_CRON) ctx.waitUntil(pollSatellites(env, now));
     else ctx.waitUntil(pollSpaceWeather(env, now));
   },
 } satisfies ExportedHandler<Env>;
   ]);
 }
+async function pollSatellites(env: Env, now: Date): Promise<void> {
+  try {
+    const elements = await fetchElements();
+    await env.DB.prepare("INSERT INTO feed_snapshots (feed, fetched_at, ok, body) VALUES ('celestrak', ?1, 1, ?2) ON CONFLICT (feed) DO UPDATE SET fetched_at = ?1, ok = 1, body = ?2")
+      .bind(now.toISOString(), JSON.stringify(elements)).run();
+  } catch (e) {
+    console.error("celestrak", String(e));
+    await env.DB.prepare("INSERT INTO feed_snapshots (feed, fetched_at, ok) VALUES ('celestrak:error', ?1, 0) ON CONFLICT (feed) DO UPDATE SET fetched_at = ?1").bind(now.toISOString()).run();
+  }
+}
 async function pollSpaceWeather(env: Env, now: Date): Promise<void> {
   let w: SpaceWeather;
   try {

server/test/celestrak.test.ts added +16

@@ -0,0 +1,16 @@
	1	import assert from "node:assert/strict";
	2	import { test } from "node:test";
	3	import { pick } from "../src/celestrak.ts";
	4
	5	test("keeps only the SGP4 fields", () => {
	6	// CelesTrak GP JSON for the ISS, 2026-10-18.
	7	const row = {
	8	OBJECT_NAME: "ISS (ZARYA)", OBJECT_ID: "1998-067A", EPOCH: "2026-10-18T03:28:15.076416", MEAN_MOTION: 15.48918166,
	9	ECCENTRICITY: 0.000678, INCLINATION: 51.6328, RA_OF_ASC_NODE: 51.6259, ARG_OF_PERICENTER: 277.7856, MEAN_ANOMALY: 82.2363,
	10	EPHEMERIS_TYPE: 0, CLASSIFICATION_TYPE: "U", NORAD_CAT_ID: 25544, ELEMENT_SET_NO: 999, REV_AT_EPOCH: 59081, BSTAR: 0.00014456,
	11	MEAN_MOTION_DOT: 7.503e-05, MEAN_MOTION_DDOT: 0,
	12	};
	13	const [o] = pick([row]);
	14	assert.deepEqual(Object.keys(o).sort(), ["ARG_OF_PERICENTER", "BSTAR", "ECCENTRICITY", "EPOCH", "INCLINATION", "MEAN_ANOMALY", "MEAN_MOTION", "NORAD_CAT_ID", "OBJECT_NAME", "RA_OF_ASC_NODE"]);
	15	assert.equal(o.NORAD_CAT_ID, 25544);
	16	});

server/wrangler.jsonc +1 −1

	@@ -2,7 +2,7 @@
2	"name": "moonrise-server",	2	"name": "moonrise-server",
3	"main": "src/index.ts",	3	"main": "src/index.ts",
4	"compatibility_date": "2026-10-01",	4	"compatibility_date": "2026-10-01",
5	"triggers": { "crons": ["/5 * * ", "/10 * * * *"] },	5	"triggers": { "crons": ["/5 * * ", "/10 * * * ", "7 /2 * * *"] },
6	"d1_databases": [	6	"d1_databases": [
7	{	7	{
8	"binding": "DB",	8	"binding": "DB",