APTDecoder Julia package repo.
datatime, (channelA,channelB), data = decode(y,Fs)
Decode the APT image in a time series
y defined at a frequency
Fs (in Hz).
datatime is the time in seconds counting from the beginning of the recording.
channelB are arrays representing the data from the two different channels (A and B).
data is raw data as an array including channel A and B, as well sync markers and telemetry.
using FileIO using APTDecoder wavname = "gqrx_20190804_141523_137100000.wav" y,Fs,nbits,opt = load(wavname) datatime,(channelA,channelB),data = APTDecode.decode(y,Fs)
lon,lat = APTDecoder.georeference(channel,satellite_name,datatime,starttime; eop = nothing, tles = get_tle(:weather))
lon and latitude
lat of the NOAA APT satellite data
channel using the orbit of the satellite with the name
satellite_name (generally "NOAA 15", "NOAA 18", "NOAA 19").
channel (channel A or channel B) are returned by the function
starttime is the date (
DateTime) of beginning of the capture. The optional parameter
tles are the two-line elements (TLEs) data (download if necessary).
The optional parameter
eop are the Earth Orientation Parameters (see https://juliaspace.github.io/SatelliteToolbox.jl for more information)
plon,plat,data = APTDecoder.georeference(pngname,satellite_name,channel,...)
Compute longitude and latitude of the NOAA APT satellite image in
pngname using the orbit of the satellite with the name
satellite_name (generally "NOAA 15", "NOAA 18", "NOAA 19"). The file name
pngname should have the followng structure:
gqrx_20190811_075102_137620000.png. Date and time of the file name are in UTC. The parameter
'b' for the two transmitted wave-length.
Optional arguments are
starttime for the date (
DateTime) of capture (deduced from the filename per default) and
tles for the two-line elements (TLEs) data (download if necessary).
satellite_name = "NOAA 15" pngname = "gqrx_20190811_075102_137620000.png"; channel = 'a' APTDecoder.georeference(pngname,satellite_name,channel)
tles = get_tle(:weather)
Load the two-line elements (TLEs) data from https://www.celestrak.com for weather satellites.
Decodes the APT signal in
wavname as recorded by gqrx using wide FM-mono demodulation. The file name
wavname should have the followng structure:
gqrx_20190811_075102_137620000.wav. Date and time of the file name are in UTC (not local time).
satellite_name is the name of the satellite (generally
import APTDecoder wavname = "gqrx_20190825_182745_137620000.wav" APTDecoder.makeplots(wavname,"NOAA 15")