[Orekit Users] Orekit 7.1 released

[MAISONOBE Luc <luc.maisonobe@c-s.fr>]

The Orekit team is pleased to announce that version 7.1 of Orekit has  
been released today.

Version 7.1 is a minor release of Orekit. It introduces several new  
features and bug fixes. The most important features introduced in  
version 7.1 are:

 - a lot of new event detectors
    * field of view based detectors supporting any FoV shape, either  
on ground targeting spacecraft
      or on spacecraft and targeting ground defined zones with any shape
    * extremum elevation detector, anomaly, latitude argument, or  
longitude argument crossing detectors,
      either true, mean or eccentric,
    * latitude and longitude extremum detectors,
    * latitude and longitude crossing detectors

 - new event filtering capability based on user-provided predicate function,

 - ability to customize DSST interpolation grid for short period elements,

 - ability to retrieve DSS short periodic coefficients,

 - removed some arbitrary limitations in DSST tesseral and zonal contribution,

 - ability to set short period degree/order to smaller values than  
mean elements in DSST

 - vastly improved frames transforms efficiency for various Earth frames,

 - three different types of solar radiation pressure coefficients,

 - new tabulated attitudes related to Local Orbital Frame,

 - smooth attitude transitions in attitudes sequences, with derivatives
   continuity at both endpoint,

 - ground zone sampling either in tiles or grid with fixed or  
track-based orientation,

 - derivatives handling in geodetic points,

 - parsing of TLE with non-unclassified modifiers,

 - support for official WMM coefficients from NOAA,

 - support for tai-utc.dat file from USNO,

 - tropospheric refraction model following Recommendation ITU-R P.834-7,

 - geoid model based on gravity field,

 - use of the new Apache Commons Math rotation API with either Frame  
transform convention
   or vector operator convention.

Numerous bugs were also fixed.

Version 7.1 depends on version 3.6 of Apache Commons Math.

Note that contrary to what was announced last year, the orbit determination
is not yet available in 7.1. This is due to some administrative delays, we
are sorry about that. We are still committed to deliver orbit determination
as soon as possible. In fact, we expect to do this before Summer. As it is
a really important and highly expected feature, a new release will be  
performed
when OD can be published freely. So you can expect a version 7.2 with OD
in just a few months.

best regards,

Luc Maisonobe, on behalf of the Orekit team