Mar 23, 2011

Cohen Kappa for classification accuracy control

Useful Cohen Kappa statistics tools:

Philippe Bonnardel program (Kappa.exe) - detailed kappa statistics for data up to 25 classes
Pedro Femia Marzo & Antonio Martín Andres tool (Delta 3.2) - delta and kappa measures of agreement between categorical data Читать дальше......

GeoTagging of gigital photos how-to

Tools for GeoTagging of digital photography.

Hardware: GPS Garmin Summit HC + Digital camera Canon EOS Rebel XS + PC
Software:
1. Canon EOS Utility 2.8.1
2. DNR Garmin 5.4.1
3. GPSCorrelate 1.5.6 (win)
4. ExifTool 8.52 (win) + ExifTool-GUI 4.08 (win, optional)
5. MS Excel 2007
6. ArcGIS Decktop 9.3 or any compatible GIS application

While taking photos, digital camera clock should be verified with GPS time, don'to forget tunrn on GPS and to record track.
Step 1. Download photos from camara with EOS Utility (in JPEG)
Step 2. Download GPS track with DNR Garmin (save in GPX format, also it is useful to save it in vector SHP format to have track visualization)
Step 3. Use GPSCorrelate to set individual EXIF geographical metadata in JPEG pictures (whole directory) in base of GPS track (check that Time Zone setting is correct)
Step 4 (optional). Extract geographical metadata just stored in JPEG pictures to list in text file, using ExifTool. In command line it looks like: exiftool.exe -T -r -filename -GPSLatitudeRef -GPSLatitude -GPSLongitudeRef -GPSLongitude -GPSAltitude -DateTimeOriginal e:\Photoes_temp\ > coord_list.txt
Step 5 (optional). Import text file as tab separated table to Excel, use formulas similar to next ones: [=LEFT(C2,FIND(" deg ",C2,1)-1)], [=MID(C2,FIND(" deg ",C2,1)+5,(FIND("' ",C2,1)-FIND(" deg ",C2,1)-5))], [=MID(C2,FIND("' ",C2,1)+1,(FIND(" N",C2,1)-FIND("' ",C2,1)-2))], [=I2+J2/60+K2/3600] to transform strings with coordinates to degrees with fractions.
Step 6 (optional). Import Excel file to ArcGIS, visualize table data using "Display XY data" context menu option (don't forget to select correct coordinate system, like GCS_WGS_1984, or another one depending on GPS data), save visualized layer through "Data->Export data" like point shapefile (SHP). Читать дальше......

Mar 15, 2011