Warning: This code is experimental; please see the LICENSE.
A tool to convert to and from various general perturbations orbital data formats. See this discussion for some background.
Supported formats:
Currently not all round trips starting from Celestrak data are perfect. (Floating point number formatting is only one class of challenge there.)
This tool can also perform SGP4 propagation (using this implementation), object renaming, and random walks.
Usage: tletool transform|prop|on-orbit|walk|rename|sample|random ...
Subcommands:
transform:
-buf-size int
Buffer size (default 4096)
-help
Just get help
-tolerate
Log errors instead of stopping
-emit string
Output represention: csv|csvh|json|jsonarray|tle|kvn|xml (default "csv")
csvh emits CSV output with a header line.
json emits each element set as a single line of JSON.
jsonarray emits an array of element sets as one big blob of JSON.
prop: Propagate
-duration duration
Duration of propagation (instead of -to)
-from string
Propagation start time (default "2020-12-18T16:42:22.644764256Z")
-higher-precision
Higher-precision (as able) (default true)
-interval duration
Propagation end time (default 10m0s)
-to string
Propagation end time (default "2020-12-18T17:42:22.644764256Z")
on-orbit: Filter for on-orbit
-from string
Propagation start time (default "2020-12-18T16:42:22.644764256Z")
-interval duration
Propagation end time (default 10m0s)
-to string
Propagation end time (default "2020-12-18T17:42:22.644764256Z")
walk: Random walk
-inc-set
Increment element set number (default true)
-max-steps int
Maximum number of steps (default 3)
-min-steps int
Minimum number of steps (default 1)
-reset-epoch
Set Epoch to now (default true)
-seed int
RNG seed (defaults to current time in ns) (default 1608309742644776587)
rename: Update name, catalog number
-clear
Remove original name (suffix)
-state int
Next catalog number in Alpha-5 A range
Sample: Sampled based on hash of name+id+num
-mod int
Sampling hash modulus (default 10)
-rem int
Sampling hash remainder
Random: Emit a percentage of the input
-percent float
Approximate percent of lines to emit
(The default timestamps are acutally the current time.)
With this
data
from space-track.org:
# We'll needlessly exercise our transformations.
cat tmp/now.json |
tletool transform -emit xml |
tletool transform -emit kvn |
tletool transform -emit csv |
tletool transform -emit json |
tletool prop |
tail -4 |
jq -r -c '{"NORAD":.Norad,"LLA":.LLA}'
gives
{"NORAD":270288,"LLA":{"Lat":65.84531,"Lon":-14.565547,"Alt":1292.6202}}
{"NORAD":270288,"LLA":{"Lat":33.46682,"Lon":-17.518644,"Alt":1285.534}}
{"NORAD":270288,"LLA":{"Lat":0.9417589,"Lon":-20.208746,"Alt":1283.9185}}
{"NORAD":270288,"LLA":{"Lat":-31.554588,"Lon":-22.894846,"Alt":1292.9807}}
if [ ! -f data/test.kvn ]; then
curl 'https://celestrak.com/NORAD/elements/gp.php?GROUP=STATIONS&FORMAT=KVN' > data/test.kvn
fi
# We'll needlessly exercise our transformations, and we'll keep
# the intermediate output.
cat data/test.kvn |
tletool transform -emit json |
tee data.json |
tletool transform -emit xml |
tee data.xml |
tletool transform -emit csv |
tee data.csv |
tletool transform -emit kvn |
tee data.kvn |
tletool on-orbit |
tee on-orbit.json |
tletool prop |
tee prop.json |
head -1 |
jq -r .results in something that looks like
{
"Age": 32705.934428877,
"At": "2020-12-14T21:29:18.874844877Z",
"Id": "1998-067A",
"LLA": {
"Lat": 17.104858,
"Lon": 87.40023,
"Alt": 420.42767
},
"Name": "ISS (ZARYA)",
"Norad": 25544,
"State": {
"V": {
"X": -4.775169,
"Y": -2.1982052,
"Z": -5.5731597
},
"ECI": {
"X": -4493.6265,
"Y": 4695.992,
"Z": 1987.5846
}
}
}in addition to several intermediate output files.
The example above uses jq.