[Proj] cs2cs usage

[Frank Warmerdam]

marco.pasetti at alice.it wrote:
> Hi all,
>  
> I read cs2cs manual page, but I still have big doubts about it! quickly:
>  
> 0. Preamble: I built PROJ.4 4.6 on windows using MinGW
>  
> 1. Question 1: when I launch cs2cs from command line it executes the requested operation and then waits for others inputs... how can I quit, without the need of killing the process in task manager?

Marco,

You normally need to indicate "end of input" to terminate cs2cs.  On unix
this is done with control-D, on windows with control-Z.

> 2. Question 2: I need to trasform single points from WGS84 (EPSG ID = 4326) to Gauss-Boaga Roma40 West (EPSG ID = 3003)
> while ID=4326 determinates an univocal datum, to correctly define Gauss-Boaga Roma40 West I need to specify also +towgs84 parameters, retrieved by GRASS (creating a new location in GRASS using 3003 EPSG code, it asks for furthers options, suggesting the correct parameters to set):
> the complete datum definition for Gauss-Boaga Roma40 West is as follows (from GRASS):
>  
> EPSG ID = 3003
> Option 2
> Used in Italy (Peninsular Part)
> towgs84=-104.1,-49.1,-9.9,0.971,-2.917,0.714,-11.68
> Accuracy 3-4m
>  
> how can I use cs2cs respecting the previous parameters?
> I tried with cs2cs +init=epsg:4326 +to +init=epsg:3003
> but I don't know how to set towgs84 parameters (and even if they are needed)

The epsg:3003 definition looks like:

+proj=tmerc +lat_0=0 +lon_0=9 +k=0.9996 +x_0=1500000 +y_0=0 +ellps=intl 
+units=m +no_defs  <>

So you should use it directly and then add your towgs84 parameter.

eg.

cs2cs +init=epsg:4326 +to \
+proj=tmerc +lat_0=0 +lon_0=9 +k=0.9996 +x_0=1500000 +y_0=0 +ellps=intl \
+units=m +towgs84=-104.1,-49.1,-9.9,0.971,-2.917,0.714,-11.68 +no_defs

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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