update README and NEWS

2 files changed, 27 insertions, 17 deletions

diff --git a/NEWS b/NEWS
index 7f61e21..e7e0949 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,9 @@ gipfel ChangeLog
 gipfel-0.2.8
 * Fix issue with image saving on some platforms (reported by David Mitchell).
 * Fix crash in stitching mode.
+* Add a note to the README about generating a data file for the USA from
+  [USGS](http://geonames.usgs.gov/domestic/download_data.htm) data
+  (pointed out by David Mitchell).
 
 gipfel-0.2.7
 * Import data from http://www.viewfinderpanoramas.org/ with the
diff --git a/README b/README
index bb6822e..4669ed9 100644
--- a/README
+++ b/README
@@ -24,11 +24,11 @@ compute the viewing paramteres from the given data points.
 
 Requirements
 ------------
-* fltk-1.1.x <http://www.fltk.org>
-* libtiff <http://www.remotesensing.org/libtiff/>
-* libjpeg <http://www.ijg.org/>
-* exif utility <http://libexif.sourceforge.net/>
-* GSL - GNU Scientific Library <http://www.gnu.org/software/gsl/>
+* [fltk-1.1.x](http://www.fltk.org)
+* [libtiff](http://www.remotesensing.org/libtiff/)
+* [libjpeg](http://www.ijg.org/)
+* [exif utility](http://libexif.sourceforge.net/)
+* [GSL - GNU Scientific Library](http://www.gnu.org/software/gsl/)
 * gipfel works on UNIX-like systems (e.g. Linux, *BSD and probably others)
 
 Installation
@@ -66,8 +66,8 @@ If you have positioned at least two mountains, you can click on
 the "comp" button in the control window to compute the
 parameters of the picture.
 
-You may also want to have a look at the screen video at
-<http://www.ecademix.com/JohannesHofmann/gipfel.avi>
+You may also want to have a look at the
+(screen video)[http://www.ecademix.com/JohannesHofmann/gipfel.avi]
 for an example session.
 
 Data File
@@ -83,18 +83,25 @@ Each line must contain the following values separated by a comma:
 The following line is a valid example:
 	SMTSBG,Simetsberg,,47.56617,11.25358,1836
 
-Fortunately, there is a great website <http://www.alpin-koordinaten.de>,
+Fortunately, there is a [great website](http://www.alpin-koordinaten.de),
 where you can download a suitable file containg quite a lot of data mostly 
 concerning the alps:
 Click on the "Suchen" button and the click on the diskette symbol below
 the first table then select "Fugawi 3 TXT" format and click on "Download".
 
 Obviously you can easily add your own entries to the data file or add them
-to the database at <http://www.alpin-koordinaten.de>.
+to the database at http://www.alpin-koordinaten.de.
 
-Thanks to the kind permission of the creators of
-<http://www.alpin-koordinaten.de>, the standard gipfel tarball includes
-a default datafile generated by <http://www.alpin-koordinaten.de>.
+Thanks to the kind permission of
+[Jonathan de Ferranti](http://www.viewfinderpanoramas.org/) and the
+creators of http://www.alpin-koordinaten.de, the standard gipfel
+tarball includes a default datafile generated from these two sources.
+
+For the USA, you can download a data file
+from [USGS](http://geonames.usgs.gov/domestic/download_data.htm)
+The file can be transformed for gipfel with
+	awk 'BEGIN {FS="|"; OFS=","};
+	     $3 == "Summit" {print "usgs_" $1, $2,"" , $10, $11, $16};'
 
 GPS Tracks
 ----------
@@ -130,8 +137,8 @@ are displayed in blue.
 Refraction
 ----------
 Refraction caused by temperature and density gardients in the atmosphere is
-taken into account according to the approximation described by Tom Chester in:
-<http://tchester.org/sgm/analysis/peaks/refraction_calculation.html>
+taken into account according to the approximation described by
+[Tom Chester](http://tchester.org/sgm/analysis/peaks/refraction_calculation.html).
 under the assumption of a temperature change of 6.5°C per 1000m and a
 temperature T0 at view point level of 10°C.
 
@@ -213,10 +220,10 @@ Troubleshooting
 
 Acknowledgements
 ----------------
-Thanks to the guys from <http://www.alpin-koordinaten.de> for their public
+Thanks to the guys from http://www.alpin-koordinaten.de for their public
 GPS database. 
-Also have look at their other site <http://www.alpen-panoramen.de>.
-In newer versions I use maxima <http://maxima.sourceforge.net/> for
+Also have look at their other [site](http://www.alpen-panoramen.de).
+In newer versions I use [maxima](http://maxima.sourceforge.net/) for
 symbolic computation and code generation.
 I also want to thank my brother Martin for his suggestions and the
 discussions.