-
Notifications
You must be signed in to change notification settings - Fork 7
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
37 changed files
with
15,356 additions
and
17,644 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
77 changes: 77 additions & 0 deletions
77
maps4cim-core/src/main/java/de/nx42/maps4cim/map/relief/Viewfinder.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,77 @@ | ||
| package de.nx42.maps4cim.map.relief; | ||
|
|
||
| /** | ||
| * source: http://www.viewfinderpanoramas.org/dem3.html | ||
| * | ||
| * | ||
| */ | ||
| public class Viewfinder { | ||
|
|
||
| /* | ||
| * HGT File Format | ||
| * (source: http://www.viewfinderpanoramas.org/dem3.html#hgt) | ||
| * | ||
| * An HGT file covers an area of 1°x1°. Its south western corner can be | ||
| * deduced from its file name: for example, n51e002.hgt covers the area | ||
| * between N 51° E 2° and N 52° E 3°, and s14w077.hgt covers S 14° W 77° to | ||
| * S 13° W 76°. The file size depends on the resolution. If this is 1", | ||
| * there are 3601 rows of 3601 cells each; if it is 3", there are 1201 rows | ||
| * of 1201 cells each. The rows are laid out like text on a page, starting | ||
| * with the northernmost row, with each row reading from west to east. Each | ||
| * cell has two bytes, and the elevation at that cell is | ||
| * 256*(1st byte) + (2nd byte). It follows that a 3" HGT file has a file | ||
| * length of 2 x 1201 x 1201. SRTM 3" cells are calculated by calculating | ||
| * the mean of 1" cells and their eight neighbors. | ||
| * It follows that the highest local point is likely to be higher than the | ||
| * highest SRTM 3" cell. The difference should vary with the steepness of | ||
| * the local relief. | ||
| */ | ||
|
|
||
| /* | ||
| * Tile package URL retrieval | ||
| * | ||
| * OK, this is kinda messed up, as there is no proper tile package index | ||
| * available and the naming is totally inconsistent. | ||
| * This however is not the case for the tiles themselves, these are named | ||
| * consistently r"[n|s]\d\d[e|w]\d\d\d.hgt", e.g. "n51e002.hgt" | ||
| * | ||
| * A possible solution would be parsing the available overview maps | ||
| * - http://www.viewfinderpanoramas.org/Coverage%20map%20viewfinderpanoramas_org3.htm | ||
| * - http://www.imagico.de/files/ferranti.php | ||
| * - http://www.imagico.de/files/ferranti.php?list=dem1list.txt | ||
| * now we could deduce the locations from the pixels of the overview maps | ||
| * | ||
| * Better approach: read the package lists | ||
| * - http://www.viewfinderpanoramas.org/dem3list.txt | ||
| * - http://www.viewfinderpanoramas.org/dem1list.txt | ||
| * or get download links from this site: | ||
| * - http://www.imagico.de/map/demsearch.php | ||
| * | ||
| * These follow a specific pattern: | ||
| * id:path[:info], e.g. U22:/dem3/U22.zip or AN2:/ANTDEM3/16-30.zip:-90:-90:-60:-0 | ||
| * | ||
| * id (tolowercase) can be: | ||
| * - "[n|s]\d\d[e|w]\d\d\d", e.g. n47e006: parse directly | ||
| * - "s?[a-z]\d\d", e.g. SM18: convert using algorithm below | ||
| * - otherwise: use coordinates from comment, see algorithm below | ||
| * | ||
| * short notation to available tiles: | ||
| * west-east in steps of 6°: | ||
| * 01 = 180..175°W, 02 = 174..169°W, 30 = 6..1°W, 31 = 0..5°E, 60 = 175..180°E | ||
| * north-south in steps of 4°: | ||
| * U = 80..83°N, A = 0..3°N, SA = 1..4°S, SN = 53..56°S | ||
| * | ||
| * comment to coordinates (e.g. "63:-25:67:-13") | ||
| * n63w25 to n66w14, last coordinates are exclusive! | ||
| * | ||
| * downloaded files can contain multiple .hgt files in several subfolders | ||
| * as well as unrelated files (readmes, etc.). | ||
| * To get all relevant data, list all files and filter with | ||
| * r"[n|s]\d\d[e|w]\d\d\d.hgt" | ||
| * | ||
| * | ||
| * | ||
| * | ||
| */ | ||
|
|
||
| } |
Oops, something went wrong.