To use the N values as a part of 12d Models Survey Data Reduction (SDR) in NSW,ACT or SA. For other Australian States, please refer to links at the bottom of this post.
1st step: Download the following data.
Contained in the zip file are the necessary files to support both MGA94 and MGA2020. The data is a series of tiles (they correspond to the 1:250000 map series) from which 12d interpolates the N Values.
When you extract it please extract it to C:\ It contains full paths within the file, and will place config files into both V12 and V14.
Right click on the zip file, choose extract all, and enter C:\
It will set up the .dat files in an area common to both V12 and V14. Pleas delete any other winter/n_values folders in either 12 or 14 if you nave previously installed them to free up space on your harddrive.
Please note V12 only has support for MGA 94, for use in MGA 2020 V14 is essential
For V12 the following needs to ne set in your env.4d file
In version 14 the following changes will need to be made to your env.4d file:
If you are using an env_config file then the following 2 rows can be added:
WINTER_DATA_AUSGeoid09_4D Edited C:\12d\Winter_data\WINTER_DATA_AUSGeoid09
WINTER_DATA_AUSGeoid2020_4D Edited C:\12d\Winter_data\WINTER_DATA_AUSGeoid2020
For the N_Value files for other Australian States.
Queensland – TMR provide the files as part of their customisation. When installed the files will be located in the following directory “C:\ProgramData\TMR\12d.Model\V14.1.1\User_Lib\Survey\Winter_data”.