5 replies to this topic

[gianluca]

Dear all,
I'm working with Greek maps in 1:5.000.
On the corners of the map there are the coordinates in degrees, minutes and seconds.
Unfortunately, there are no information about projection, datum,...
If I assume that they are WGS84, they are off if i compare with other (correctly) georeferenced cartography I have.
If I try to shift the map to fit the others, i see that a coordinate like this
25°52'00''
35°12'00''
becames
25°51'58.70''
35°11'55.60''
with a difference of approximately -1.30 Long and -4.40 Lat.
If I assume that they are in other coordinates systems (usually used in Greece), the map is much more off than these values i underlined before.
On the same map, there are also other coordinates information which I cannot understand too.

I was wondering if someone can help me with this.
Thank you in advance for your time and consideration

Attached Files

•  sample96278.jpg   994.21K   70 downloads

[Aris]

Hi

Generally maps 1/5000 are based on the Bessel ellipsoid (1841) system and the projected one is called Hatt. The values shown on the corner of your map should be The Bessel ellipsoid and the values shown on the side (-5000 and -5500) are the projected one (Hatt). This is the old coordinate system, nowadays Greece uses more EGSA87 (GGRS in ESRI). There is a free software with witch you can make the transformation from Hatt to EGSA you can find it here
http://users.auth.gr...k/coords_gr.zip
I hope this will help.

Aris

Dear all,
I'm working with Greek maps in 1:5.000.
On the corners of the map there are the coordinates in degrees, minutes and seconds.
Unfortunately, there are no information about projection, datum,...
If I assume that they are WGS84, they are off if i compare with other (correctly) georeferenced cartography I have.
If I try to shift the map to fit the others, i see that a coordinate like this
25°52'00''
35°12'00''
becames
25°51'58.70''
35°11'55.60''
with a difference of approximately -1.30 Long and -4.40 Lat.
If I assume that they are in other coordinates systems (usually used in Greece), the map is much more off than these values i underlined before.
On the same map, there are also other coordinates information which I cannot understand too.

I was wondering if someone can help me with this.
Thank you in advance for your time and consideration

[gianluca]

Hi Aris,
Thanks really a lot.
The software you gave me, needs a greek operating systems, but I guess I can manage with a virtual pc.
It looks to be a bit complicated, but it seems to be very usefull to me.
Thank you really a lot.
See you

Hi

Generally maps 1/5000 are based on the Bessel ellipsoid (1841) system and the projected one is called Hatt. The values shown on the corner of your map should be The Bessel ellipsoid and the values shown on the side (-5000 and -5500) are the projected one (Hatt). This is the old coordinate system, nowadays Greece uses more EGSA87 (GGRS in ESRI). There is a free software with witch you can make the transformation from Hatt to EGSA you can find it here
http://users.auth.gr...k/coords_gr.zip
I hope this will help.

Aris

Dear all,
I'm working with Greek maps in 1:5.000.
On the corners of the map there are the coordinates in degrees, minutes and seconds.
Unfortunately, there are no information about projection, datum,...
If I assume that they are WGS84, they are off if i compare with other (correctly) georeferenced cartography I have.
If I try to shift the map to fit the others, i see that a coordinate like this
25°52'00''
35°12'00''
becames
25°51'58.70''
35°11'55.60''
with a difference of approximately -1.30 Long and -4.40 Lat.
If I assume that they are in other coordinates systems (usually used in Greece), the map is much more off than these values i underlined before.
On the same map, there are also other coordinates information which I cannot understand too.

I was wondering if someone can help me with this.
Thank you in advance for your time and consideration

[gianluca]

Dear Aris/Dear all,
I still cannot manage to convert in the right way. I mean that I still cannot use the software you suggested me untill I take the Greek WinXp.
I tried with other softwares, considering the coordinate as Bessel 1841, but the problem is that maps are not going where they have to be.
May I ask you to convert for me one set of coordinates with the free software you linked?
35°12'00'' Lat
25°52'00'' Long

I just want to see if this is the right input (and output) setting.
As I said before, it seems that the difference between the coordinate I read on the map and the one (wgs84) I see comparing with other maps is around:
minus 1.30 Long
minus 4.40 Lat
If possible, I would also ask you to be so kind to suggest me another software to do the same conversion.
Thank you again,
Gianluca

Hi

Generally maps 1/5000 are based on the Bessel ellipsoid (1841) system and the projected one is called Hatt. The values shown on the corner of your map should be The Bessel ellipsoid and the values shown on the side (-5000 and -5500) are the projected one (Hatt). This is the old coordinate system, nowadays Greece uses more EGSA87 (GGRS in ESRI). There is a free software with witch you can make the transformation from Hatt to EGSA you can find it here
http://users.auth.gr...k/coords_gr.zip
I hope this will help.

Aris

Dear all,
I'm working with Greek maps in 1:5.000.
On the corners of the map there are the coordinates in degrees, minutes and seconds.
Unfortunately, there are no information about projection, datum,...
If I assume that they are WGS84, they are off if i compare with other (correctly) georeferenced cartography I have.
If I try to shift the map to fit the others, i see that a coordinate like this
25°52'00''
35°12'00''
becames
25°51'58.70''
35°11'55.60''
with a difference of approximately -1.30 Long and -4.40 Lat.
If I assume that they are in other coordinates systems (usually used in Greece), the map is much more off than these values i underlined before.
On the same map, there are also other coordinates information which I cannot understand too.

I was wondering if someone can help me with this.
Thank you in advance for your time and consideration

[zio]

Hi Gianluca,

I am starting to work with Greek maps, in the best case 1:5000. Could you tell me where I can purchase these maps.
That would be really helpful. Thanks a lot!
zio

Dear all,
I'm working with Greek maps in 1:5.000.
On the corners of the map there are the coordinates in degrees, minutes and seconds.
Unfortunately, there are no information about projection, datum,...
If I assume that they are WGS84, they are off if i compare with other (correctly) georeferenced cartography I have.
If I try to shift the map to fit the others, i see that a coordinate like this
25°52'00''
35°12'00''
becames
25°51'58.70''
35°11'55.60''
with a difference of approximately -1.30 Long and -4.40 Lat.
If I assume that they are in other coordinates systems (usually used in Greece), the map is much more off than these values i underlined before.
On the same map, there are also other coordinates information which I cannot understand too.

I was wondering if someone can help me with this.
Thank you in advance for your time and consideration

[gianluca]

Hi there,
Sorry for the delay.
You can find them in the Hellenic Military Geographical Service in Athens.
You can even have an idea of the sheet you need by looking at http://web.gys.gr/ (you still cannot order them online, as far as I know).
Let me know if you need more help.
All the best,
Gianluca

Hi Gianluca,

I am starting to work with Greek maps, in the best case 1:5000. Could you tell me where I can purchase these maps.
That would be really helpful. Thanks a lot!
zio

Dear all,
I'm working with Greek maps in 1:5.000.
On the corners of the map there are the coordinates in degrees, minutes and seconds.
Unfortunately, there are no information about projection, datum,...
If I assume that they are WGS84, they are off if i compare with other (correctly) georeferenced cartography I have.
If I try to shift the map to fit the others, i see that a coordinate like this
25°52'00''
35°12'00''
becames
25°51'58.70''
35°11'55.60''
with a difference of approximately -1.30 Long and -4.40 Lat.
If I assume that they are in other coordinates systems (usually used in Greece), the map is much more off than these values i underlined before.
On the same map, there are also other coordinates information which I cannot understand too.

I was wondering if someone can help me with this.
Thank you in advance for your time and consideration