README
¶
satellite
import "github.com/joshuaferrara/go-satellite"
Intro
I decided to port the SGP4 library to GoLang as one of my first projects with the language. I've included a test suite to ensure accuracy.
Usage
Constants
const DEG2RAD float64 = math.Pi / 180.0
const RAD2DEG float64 = 180.0 / math.Pi
const TWOPI float64 = math.Pi * 2.0
const XPDOTP float64 = 1440.0 / (2.0 * math.Pi)
func ECIToLLA
func ECIToLLA(eciCoords Vector3, gmst float64) (altitude, velocity float64, ret LatLong)
Convert Earth Centered Inertial coordinated into equivalent latitude, longitude, altitude and velocity. Reference: http://celestrak.com/columns/v02n03/
func GSTimeFromDate
func GSTimeFromDate(year, mon, day, hr, min, sec int) float64
Calc GST given year, month, day, hour, minute and second
func JDay
func JDay(year, mon, day, hr, min, sec int) float64
Calc julian date given year, month, day, hour, minute and second the julian date is defined by each elapsed day since noon, jan 1, 4713 bc.
func Propagate
func Propagate(sat Satellite, year int, month int, day, hours, minutes, seconds int) (position, velocity Vector3)
Calculates position and velocity vectors for given time
func ThetaG_JD
func ThetaG_JD(jday float64) (ret float64)
Calculate GMST from Julian date. Reference: The 1992 Astronomical Almanac, page B6.
type LatLong
type LatLong struct {
Latitude, Longitude float64
}
Holds latitude and Longitude in either degrees or radians
func LatLongDeg
func LatLongDeg(rad LatLong) (deg LatLong)
Convert LatLong in radians to LatLong in degrees
type LookAngles
type LookAngles struct {
Az, El, Rg float64
}
Holds an azimuth, elevation and range
func ECIToLookAngles
func ECIToLookAngles(eciSat Vector3, obsCoords LatLong, obsAlt, jday float64) (lookAngles LookAngles)
Calculate look angles for given satellite position and observer position obsAlt in km Reference: http://celestrak.com/columns/v02n02/
type Satellite
type Satellite struct {
Line1 string
Line2 string
}
Struct for holding satellite information during and before propagation
func ParseTLE
func ParseTLE(line1, line2 string, gravConst Gravity) (sat Satellite)
Parses a two line element dataset into a Satellite struct
func TLEToSat
func TLEToSat(line1, line2 string, gravConst Gravity) Satellite
Converts a two line element data set into a Satellite struct and runs sgp4init
type Vector3
type Vector3 struct {
X, Y, Z float64
}
Holds X, Y, Z position
func ECIToECEF
func ECIToECEF(eciCoords Vector3, gmst float64) (ecfCoords Vector3)
Convert Earth Centered Intertial coordinates into Earth Cenetered Earth Final coordinates Reference: http://ccar.colorado.edu/ASEN5070/handouts/coordsys.doc
func LLAToECI
func LLAToECI(obsCoords LatLong, alt, jday float64) (eciObs Vector3)
Convert latitude, longitude and altitude into equivalent Earth Centered Intertial coordinates Reference: The 1992 Astronomical Almanac, page K11.
func NewSpacetrack
func NewSpacetrack(username, password string) *Spacetrack
Initialise a spacetrack API for fetching TLEs
func Spacetrack.GetTLE()
func (s *Spacetrack) GetTLE(catid uint64, ts time.Time, gravConst Gravity) (Satellite, error)
Get an initialized Satellite based on the latest TLE before the given time.
Documentation
¶
Index ¶
- Constants
- Variables
- func GSTimeFromDate(year, mon, day, hr, min, sec int) float64
- func JDay(year, mon, day, hr, min, sec int) float64
- func ThetaG_JD(jday float64) (ret float64)
- type DSComResults
- type DeepSpaceInitResult
- type DeepSpaceResult
- type DpperResult
- type GravConst
- type Gravity
- type LatLong
- type LookAngles
- type Satellite
- type Spacetrack
- type Vector3
Constants ¶
const DEG2RAD float64 = math.Pi / 180.0
const RAD2DEG float64 = 180.0 / math.Pi
const TWOPI float64 = math.Pi * 2.0
Constants
const XPDOTP float64 = 1440.0 / (2.0 * math.Pi)
Variables ¶
var ErrInvalidResponseCode = errors.New("Invalid response from spacetrack")
var ErrNotSingleSat = errors.New("not a single satellite returned")
Functions ¶
func GSTimeFromDate ¶
Calc GST given year, month, day, hour, minute and second
Types ¶
type DSComResults ¶
type DSComResults struct {
// contains filtered or unexported fields
}
A struct returned from the dscom function
type DeepSpaceInitResult ¶
type DeepSpaceInitResult struct {
// contains filtered or unexported fields
}
A struct returned from the dsinit function
type DeepSpaceResult ¶
type DeepSpaceResult struct {
// contains filtered or unexported fields
}
A struct returned from the dspace function
type DpperResult ¶
type DpperResult struct {
// contains filtered or unexported fields
}
A struct returned from the dpper function
type GravConst ¶
type GravConst struct {
// contains filtered or unexported fields
}
Holds variables that are dependent upon selected gravity model
type LatLong ¶
type LatLong struct {
Latitude, Longitude float64
}
Holds latitude and Longitude in either degrees or radians
func ECIToLLA ¶
Convert Earth Centered Inertial coordinated into equivalent latitude, longitude, altitude and velocity. Reference: http://celestrak.com/columns/v02n03/
func LatLongDeg ¶
Convert LatLong in radians to LatLong in degrees
type LookAngles ¶
type LookAngles struct {
Az, El, Rg float64
}
Holds an azimuth, elevation and range
func ECIToLookAngles ¶
func ECIToLookAngles(eciSat Vector3, obsCoords LatLong, obsAlt, jday float64) (lookAngles LookAngles)
Calculate look angles for given satellite position and observer position obsAlt in km Reference: http://celestrak.com/columns/v02n02/
type Satellite ¶
type Satellite struct {
Line1 string `json:"TLE_LINE1"`
Line2 string `json:"TLE_LINE2"`
Error int64
ErrorStr string
// contains filtered or unexported fields
}
Struct for holding satellite information during and before propagation
type Spacetrack ¶
type Spacetrack struct {
// contains filtered or unexported fields
}
Spacetrack contains an initialised API interface to space-track.org
func NewSpacetrack ¶
func NewSpacetrack(username, password string) *Spacetrack
NewSpacetrack creates an initialised API interface to space-track.org https://space-track.org allows you to create a free account, however be aware there *are* API throttles (see https://www.space-track.org/documentation#/api )
type Vector3 ¶
type Vector3 struct {
X, Y, Z float64
}
Holds X, Y, Z position
func ECIToECEF ¶
Convert Earth Centered Intertial coordinates into Earth Cenetered Earth Final coordinates Reference: http://ccar.colorado.edu/ASEN5070/handouts/coordsys.doc
Source Files