Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Some satrecs return false for position/velocity with propagate

See original GitHub issue

Having trouble with these TLEs for some reason.

FLOCK 1B-28             
1 40423U 98067FP  15219.24788283  .05567779  12028-4  14293-2 0  9997
2 40423  51.6133 170.3484 0007348 241.2767 118.7501 16.27910103 34192
MICROMAS                
1 40457U 98067GA  15213.38588329  .08885032  12472-4  72013-3 0  9998
2 40457  51.6142 195.6182 0009646 310.7124  49.3640 16.38908268 33335

When I load them, I get Uncaught TypeError: Cannot read property 'x' of undefined on line 713

Most TLEs do work though. I’m using the library to create groundtracks with D3.js

http://bl.ocks.org/syntagmatic/6c149c08fc9cde682635 http://bl.ocks.org/syntagmatic/raw/6c149c08fc9cde682635/noaa.html http://bl.ocks.org/syntagmatic/raw/6c149c08fc9cde682635/cubesat.html http://bl.ocks.org/syntagmatic/raw/6c149c08fc9cde682635/molniya.html http://bl.ocks.org/syntagmatic/raw/6c149c08fc9cde682635/gps.html http://bl.ocks.org/syntagmatic/raw/6c149c08fc9cde682635/intelsat.html

I may go digging into the source to find the error. Some of these examples can also stop working after running for a few minutes, especially Molniya.

Thanks for the awesome library. It took me just an hour or two to get something together, after spending a couple days looking into calculating ground tracks from scratch. I would love to submit some graphical, web-based examples for the library if you’re interested.

Issue Analytics

State:
Created 8 years ago
Comments:8 (2 by maintainers)

Top GitHub Comments

1reaction

terekcampbellcommented, Aug 9, 2018

Wanted to mention that the returning of [false, false] (after upgrading from 1.3.0 to 2.0.2) is an issue for myself as well

0reactions

thkruzcommented, Sep 16, 2018

I just wanted to toss out a workaround since regardless of returning undefined or false, you can’t plot it. If you use a try/catch function (https://www.w3schools.com/js/js_errors.asp) then it will catch all of the false returns and you either skip that iteration or remove the satellite (99% of my failures are decayed objects that I need to remove from my catalogue).

Top Results From Across the Web

sgp4 - PyPI

This Python package computes the position and velocity of an earth-orbiting satellite, given the satellite's TLE orbital elements from a source like ...

Julia now has a native SGP4/SDP4 implementation

The original sgp4 returns the position and velocity of the satellite at a single time tsince . My understanding is that the orbit...

Moving position in inertial with out time arrays - CesiumJS

Is there a way to have a moving position using INERTIAL Reference Frame ... const positionAndVelocity = satellite.propagate(satRec, jsDate);

Earth Satellites — Skyfield documentation - Rhodes Mill

Expect a satellite's orbit to constantly change as the SGP4 propagation ... Sun's position, it will return True when the satellite is in...

How do SDP4's "Deep space" corrections to SGP4 account for ...

There is a lot of integration going on: some things are averaged three or four ... are converted to osculating position and velocity...