Satellite Image Maps of Algeria 1:200.000

[Bart]

These maps are really GREAT, but how can I calibrate them having no IGN maps. In case where there is some town of wchih I know the coordinates and the scale of map, I handle it but in such case like i.e. Amiguid that cannot be done this way.

Has anyone any idea ?

Bart.

[Chris Scott]

Hi Roman, dont know if you need to know this but you can buy TTqv at Bracken bike shop off Old Kent Rd
020 7232 1814
Ask for John Hill, he knows the whole ttqv story

CS

[Chris Scott]

Calibrating

Joachim, the guy who designed qvtells me he is about to release a huge 5 gig DVD calibrated sat pic including Africa down to the Senegal line at a scale of about 259,000

"Price DVD 59EUR (not finally decided). Please aks me again in about 4 weeks, I will send you one. But you will need recent software to view
the maps.
There is a LIzzardtech Viewer for MAC too:
http://www.lizardtech.com/products/index.php?d=1
you need : "MrSID Viewer"

jbpcs@d63500.de

CS

[UT]

Let me clarify something: the satellite images (the ones which are not in the IGN Frame) just cover very rougly the corresponding IGN-map area. That's why they all have a different size.
Consequence: the corners can NOT be used for a calibration. This can ONLY be done with the IGN-Maps OR any other maps which show features which can be identified in the image AND in the map.

Cheers
Uli

[GWJ]

Really great site, well done and thanks a lot!

Unfortunately I have problems downloading the first three pics (the other 17 are OK and stored savely on my HDD!) Has anyone got any clues or hints?

[Fuchur]

Okay loads of people downloaded the files! Thats for sure, they are great!!

But did anyone started calibrating the rest of the images? And cant he put them online.

If you dont have webspace, drop me a line, I will put them on my homepage....

Please let me know otherwise we are all doing the same job!


------------------
CU under the Cu

Frank
http://www.crossing-africa.com .:. The Ultimate Travel on a Yamaha XT600Z

[Yves]

Sahara-Info.ch just produced a CD-ROM with 34 satellite images of the Sahara from Mauritania to Egypt. They come calibrated for Ozi and TTQV.
To fit everything on one CD, 34 scenes are in 114m/Pixel resolution and 9 of the most interesting regions (Morokko, east-Algeria, SW Libya) are in full resolution (28.5m/Pixel).
Image compression techniques used are ECW and MrSID, both supportetb by the latest Ozi and TTQV versions.
Price is 30EUR plus shipppment.

The documentation is still in german, but I will add an english section this weekend.

To know more:
http://www.sahara-info.ch/GPS/Satell...der/SatCD1.htm

Bye, Yves

[UT]

The source of most of the high resolution satellite images currently available to the public is http://zulu.ssc.nasa.gov/mrsid/. From there you can download 28.5m images of almost the whole world. Originally they are from the company Earthsat http://www.earthsat.com. The images are also sold at: http://www.geocover.com

Once downloaded, the zipped images (usually 40MB each) are in a compressed file format which can be read –after unzipping- with a free visualization program from LizardTech: http://www.lizardtech.com called: MrSID GeoViewer. It as well has the option to export the files to TIFF for further processing (and produce the maps I did in www.image-contrails.de/sat-map).
Or you can import it directly in navigation software (TTQV and OziExplorer I guess) which can read MrSID-formats. You can easily calibrate the images as in the MrSID GeoViewer UTM coordinates are displayed…

Have fun…

[Fuchur]

Via what way on http://zulu.ssc.nasa.gov/mrsid/ do you get the best resolution images, for instance via:

In - 2x - 1600 Pixels and the 100 - 1600x1200

Or an other way? Please let me know thanks!

------------------
CU under the Cu

Frank
http://www.crossing-africa.com .:. The Ultimate Travel on a Yamaha XT600Z

[UT]

Well, on http://zulu.ssc.nasa.gov/mrsid/ you first click on the tile you are interested in. Then you activate the option "Select EarthSat MrSID Image to View" (on the bottom of the graphics).
Next step, you again click on the image selected and a new window opens with an overview of the selected tile. Now you have the choice to select "Download MrSID Image". his will download the tile selected in a 28.5m/pixel resolution. The size is usually 40MB. To view the tile you first have to unzip (http://www.winzip.com/) the image and then open it with the MrSid GeoViewer as discribed...
With the MrSid GeoViewer you have the choice to extract parts to a TIFF file, which again can be imported by many graphic programs... like PaintShop Pro...

Cheers
Uli

[Grant Johnson]

Originally Posted by Fuchur

Okay loads of people downloaded the files! Thats for sure, they are great!!

But did anyone started calibrating the rest of the images? And cant he put them online.

If you dont have webspace, drop me a line, I will put them on my homepage....

Please let me know otherwise we are all doing the same job!


------------------
CU under the Cu

Frank
http://www.crossing-africa.com .:. The Ultimate Travel on a Yamaha XT600Z

I'd love to put all the GPS files here on HU - just let me know, or put me in contact with whomever, and we'll get them posted here. At least here, they'll always be available for sure! We still have stuff going back to 1998!

[Warin]

Hi,
For those using Oziexplorer ..
There is no need to convert the Mrsid images you get off the site - simply use them directly in OziExplorer - it does that fine.

Calibration of the images is a different story! For the Sydney Australia map I used a large dam in the north West corner ... had difficulty with towns id... so picking some large earth feature is important. The sydney harbour bridge was easy to pick off ... here is part of the calibration file

OziExplorer Map Data File Version 2.2
S-56-30_2000.sid
C:\OziExplorer\Maps\Australia\S-56-30_2000.sid
1 ,Map Code,
WGS 84,WGS 84, 0.0000, 0.0000,WGS 84
Reserved 1
Reserved 2
Magnetic Variation,,,E
Map Projection,(UTM) Universal Transverse Mercator,PolyCal,Yes,AutoCalOnly,No,BSBUseWPX,No
Point01,xy, 8090, 4512,in, deg, 30, 33,S, 150, 39.7872,E, grid, , , ,S
Point02,xy,23906, 3896,in, deg, 30,29.50782,S, 153, 0.75588,E, grid, , , ,S
Point03,xy,12200,30136,in, deg, 33,51.12888,S, 151,12.64158,E, grid, , , ,S
Point04,xy, 2042,37818,in, deg, 34,48.24318,S, 149,36.54786,E, grid, , , ,S
Point05,xy, 8433,38090,in, deg, 34, 51.8262,S, 150, 36.0936,E, grid, , , ,S
Point06,xy, , ,in, deg, , ,S, , ,E, grid, , , ,S

The attached text file should be renamed S-56-30_2000.map for use in Oziexplorer.

Humm 2000 might be the year the photo was taken..

[Warin]

Oziexplorer has advanced ...

Method of importing the image without doing a manual calibration ..


Yahoo! Groups

The calibration 'only' uses 2 points ... but it looks like a good calibration.
That certainly saves a lot of work.

The maps themselves. Well for OZ they are ok for the main roads .. but tracks are hidden in vegetation (and snow where that occurs in winter - yes they are taken in our winter season).