Version 1.2.4 release candidate 1

[rogerfraser]

Overview

This pull request introduces several enhancements to import and reftran to support handling of the World Geodetic System 1984 (WGS 84) and thereby closes #24. This support includes functionality for handling the WGS 84 ensemble and six specific WGS 84 realisations, including WGS 84 (Transit), WGS 84 (G730), WGS 84 (G873), WGS 84 (G1150), WGS 84 (G1674), WGS 84 (G1762), and WGS 84 (G2139).

General

• New epsg codes are added for the WGS 84 ensemble and for WGS 84 (xxxx).
• Add hard coded substitutions for WGS 84 (xxxx) to ITRFxxxx to facilitate transformation of WGS 84 data to other reference frames.
• The string wgs84 is taken to mean the WGS 84 ensemble, whereas wgs84 (xxxx) is taken to mean any one of the specific WGS 84 realisations (e.g. wgs84 (g2139)
• wgs84 is synonymous with wgs 84
• Revise exception handling to permit use of the WGS 84 ensemble and WGS 84 (xxxx).

Enhancements to import

• Permit the use of any one of the following datum strings (case insensitive) in input DNA and DynaML files, and for the default reference frame (via the command line option --reference-frame):
  wgs84 | wgs84 (transit) | wgs84 (g730) | wgs84 (g873) | wgs84 (g1150) | wgs84 (g1674) | wgs84 (g1762) | wgs84 (g2139)
• Provide a warning if wgs84 (i.e. the WGS 84 ensemble) is supplied as the default reference frame.
• Data may be supplied in either the WGS 84 ensemble or WGS 84 (xxxx) with or without an epoch.

Enhancements to reftran

• For all stations and measurements loaded from binary files, automatically substitute each occurrence of the WGS 84 ensemble or WGS 84 (xxxx) with the respective ITRFxxxx prior to undertaking a reference frame transformation.
• Any station coordinates or measurements aligned to WGS 84 without an epoch will cause reftran to terminate prematurely. Any station coordinates or measurements aligned to WGS 84 (xxxx) without an epoch, will have their epoch set to the date at which the WGS 84 (xxxx) frame realisation was adopted.
• Any attempt to transform station coordinates and measurements to WGS 84 will cause reftran to terminate prematurely.

DynAdjust User's Guide

Several changes have been made to reflect the new behaviour, including:

• 3.3.1 Reference frame receives a general overhaul and a new section entitled "Handling data aligned to WGS 84"
• Chapter 4 sees various improvements throughout, including
  • Revised epsg codes, and new epsg codes for WGS 84 (xxxx) and WGS 84 ensemble.
  • Updated 4.6.2 Relationship between ITRF, IGS and WGS 84 reference frames.
  • Updated 4.7.1 Progress reporting and import log.

Acknowledgements

Special thanks to Joel Haasdyk for his help in shaping the preferred behaviour for handling WGS 84 data.