[GRASS-user] Correctly Converting LL to LCC

[Glynn Clements]

Rich Shepard wrote:

> >> +lat_1=43.0 +lat_2=45.5 +lat_0=41.75 +lon_0=-120.5 +x_0=400000 +y_0=0 \
> >> +nadgrids=WO <<EOF
> >> 122d30'32.43"W  45d19'19.49"N
> >> 122d30'17.92"W  45d18'52.45"N
> >> 122d29'34.08"W  45d18'47.16"N
> >> EOF
> > 242511.51       398797.24 -0.00
> > 242807.02       397955.05 -0.00
> > 243757.62       397768.55 -0.00
> 
>    Please excuse any of my frustration that I inadvertently express here, but
> I just cannot get these three points correctly into GRASS so they display
> with the other maps in the project area.
> 
>    I used the GUI to import the long/lat values. Those appear OK (but I've
> not checked the decimal degrees with the original DMS input). However, when
> I run 'v.proj input=features location=sitesLL mapset=PERMANENT
> output=keysites --o' the same incorrect positions as above are produced.
> Therefore, when I try to display that map with the basin boundary and
> streams the error message is that those coordinates are outside the bounds
> of the current region.
> 
>    The middle point should have values of 796758.58 (instead of 242807.02)
> and 130579274 (instead of 397955.05).

	242807.02 / 796758.58 = 0.3047435272049408
	397955.05 / 1305792.74 = 0.3047612670905185

These look suspiciously close to 0.3048 (foot/metre conversion).

-- 
Glynn Clements <glynn at gclements.plus.com>