I want to use Projection Calibration mode. when I do that, the software wants me to anter the coordinates in degrees but I want to enter them in my national grid format. I have selected "National Grid" in the settings units manu but it doesnt work.
Please help me cause I want to use projection mode cause I know the exact projection and the exact coordinates of all four corners of my map in my national grid.
If it help, the Grid I use wasnt on the default list so I had to add it manualy
Hi,
if the coordinates you have are in your "national meter grid", then simply
use national meter grid for calibration. What is the problem in doing so ?
What grid ist it?
What units?
What are the parameters ?
From the manual I understood that Projection Calib. is more accurate than national grid.
If it isnt right I'll do NG.
Its an Israeli Grid (base on Cassini projection and Clarke 1880 Datum).
The units are metters
Hi,
Zitat von "knfevg"From the manual I understood that Projection Calib. is more accurate than national grid....
no, this is wrong. National grid calibration is definitely as exact as a proj
calibration. But, grids added by a user are always based on Transverse
Mercator projection. If your grid is "Cassini" projection, we need all the
required parameters for the respective projection and the national meter
grid and have to add it ourselves with a coming update of TTQV.
Ok, I'll give you all the parameters in the end of the letter.
However, I use 2.5 version and I guess the update will be for QV3 so it wont help me 
What is the best way to calibrate the maps in my case?
I have lots of maps to calibrate (more than 600). It actualy ONE map of israel 1:50K but broken into alot of small files.
I know the EXACT coordinates of all the corners of the small maps (this coordinates is a part of each filename).
I intendend to write a program that will build a .cal file for each .bmp file automaticly by extracting the coordinates from the filename.
If you can help me by giving me the EXACT format of the .cal file it would be great as now all I can do is guess by examples
Parametrs:
There are two Israeli grids, the old one and the new one. Both of them are in common use in Israel.
Israel OLD:
Datum: Clarke 1880 Benoit
Axis: 6378300.79
Flattening: 293.466234571
Projection: Cassini
Central Meridian: 35.21206055556
Central Parallel: 31.73409694444
Scale Factor: 1
F. Easting: 170,251.555
F. Northing: 1,126,867.909
Israeli NEW:
Datum: GRS 1980
Axis: 6378137
Flattening: 298.257222101
Projection: Transverse Mercator
Central Meridian: 35.20451694445
Central Parallel: 31.73439361
Scale Factor: 1.0000067
F. Easting: 219,529.584
F. Northing: 626,907.39
Hi,
possibly there is a way to add the grids to the latest release of
TTQV2.51, but you have to wait, until the next development release
of TTQV3 is out and the grids are included there.
Jockel, what about some explanation of the format of .cal file?
Can you give me the exect format specifications?
Hi,
Zitat von "knfevg"Jockel, what about some explanation of the format of .cal file? Can you give me the exect format specifications?
- I never needed them
- Progi never wrote them down and refuses to discuss them
- if I was looking into the ASCII file, the info required seemed to me
quite obvious
Simply cal two maps, the values you know in combination with the
differences you know about should answer all questions. This is what
people did that coded around with it.
okay, just one more question.
I am going to use Projection mode for calibration.
I have a program that convert Israeli OLD into WGS86 lat/lon (decimal mode).
Thats what I am going to use in Projection calibration. However, I cant understand one thing: if I use lat/lon values for coordinates what does it metter what projection I use?
Hi,
it does not matter what units you use.
