No subject

[Oddleiv Tungland]

Hello 

I am new to the GIS word.  One of my jobs here in this firm
is  planing of radiolinks.  My hope is to be abel to
make use of digital mapdata wihtout spending to much money.
There are special progams for this type of planing, but
they are quite expensive.



WHAT I WANT

Then I found out about GRASS and I have downloaded LINUX and
GRASS 4.1 and SPEARFISH data to see what this is all about.

1)  The most important thing for me is to be able to make a
    profile between to sites.

2)  A fine thing would be to be able to make line of sightmaps.
    
    Combining to maps to see what places are visible from
    both sites.

3)  And last make a map showing received signalstrength from 
    a transmitter at a site.

Is this possible with GRASS or should I look more in to
ARC/INFO, Intergraph ......



HOW DO I DO IT 

1)
I have found the program r.profile.  I want a list with distance and
corresponding hight.  Do I make a rastered contourmap from the data
I might have (elevation or vector data) , run r.profile?  Calculate the
distance between the two sites and suppose the reported values are
equaly spaced. Then calculate a distance for each value.
Values between contourlines I suppose is 0 so I will have to filter out them.

2)
I know there is r.los.  I guess this can be used, but radio waves are
bending more than light.  When calculating I assume that the earth radius
is (1.18 x r) and for radiowaves (1.33 x r). So I wish to make los for
different values of the eathradius.

And the values in the raster could perhaps tell me how high abow the ground
one would have to be to be seen from the radio site.

3)
It would be  nice to be able to calculat signalstrength.
This depend on pathlength, obstacles in the path, the shape of
the obstacles and so on.
Is there a GRASS progam (r.mapcalc) that can be used or do
I have to make a new one.



DATAFORMAT

What dataformat should I use and should I get elevationdata or
vector data.
There are available rasterdata (3" x 6"),  or  should I get
vector data based on scale 1:50.000.




DATA PRICES
It woud be very good if I could use GRASS and than be able to spend
the money on map-data and not on hardware and software.
The elevation data costs about $ 80.000  and you are given 50% dicount
when buying more for more than about $ 25.000.  Is this reasonable.
Norway is 325.000 km^2?







***************************************************************************
ODDLEIV TUNGLAND                              phone :  +47 22527419
Pb. 5192 Maj.                                 fax   :  +47 22527001
N-0301 OSLO                                   e-mail:  oddleiv at samkraft.no
Norway                                        packet:  la3gw at la4o     
***************************************************************************