mapproj 0.1.0

Implementation of (a part of) map projections defined in the FITS World Coordinate System (WCS)
Documentation

mapproj

Implementation of (a part of) map projections defined in the FITS World Coordinate System (WCS).

Purpose

Mainly to add projections and to support the display of FITS images in Aladin Lite V3.

Warning

This library:

  • does not support FITS reading/parsing and keywords analysis;
  • is still in an early stage (see To Do List) and will evolve when included in Aladin Lite V3.

Details

Contrary to the WCS paper, and following a previous work by F. Ochsenbein, we use the vernal point (1, 0, 0) as default projection center/origin. For zeithal projections, we thus project on the yz-plane using the euclidean coordinates instead of the equatorial coordinates. Changing the projection center correspond to a simple 3x3 matrix multiplication of the euclidean coordinates.

This work has been first done internally in 2017 (still by F.-X. Pineau), in Java, to support more projections in Aladin (not released yet, not public yet). F. Ochsenbein previously implemented TAN, STG, SIN, ZEA, ARC, AIT, SFL, MER and CEA (for lambda=1, i.e. Lambert's projection) in its AstroCoo library.

To Do list

  • Add conic projections (COD, COE, COO, COP)
  • Add cylindrical projections (CAR, CEA, CYP, MER)
  • Add hybrid projection (HPX)
  • Add pseudo cylindrical projections (AIT, MOL, PAR, SFL)
  • Add zenithal projections (AIR, ARC, AZP, FEYE, NCP, SIN, STG, SZP, TAN, ZEA, ZPN)
  • Add polyconic and pseudoconic projections (BON, PCO)?
  • Add quad cube projections (TSC, CSC, QSC)?
  • Check and possibly add constants to match WCS projection bounds
  • Support CRPIX + CD convention
  • Support CRPIX + PC + CDELT convention
  • Support CRPIX + CROTA + CDELT convention
  • Add support for LONPOLE?
  • Test and complete SIP
  • Check and add to git the pdf document containing computational details
  • Add generation of projection files and plots (like in the Java lib)

License

Like most projects in Rust, this project is licensed under either of

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.