0
votes
1answer
49 views

Using gdal merge correctly?

Currently trying to use gdal_merge within qgis to stack three raster bands, the command it's showing is like this: gdal_merge.bat -separate -of GTiff -o out.tif "LC80190302014126LGN00_B4.TIF" ...
0
votes
1answer
63 views

Georeferencing an aerial image based on satellite imagery

As part of a bigger project I need to georeference an aerial image based on a landsat image downloaded form usgs. I use qgis. can I somehow place the layers on top of each other and mark certain ...
1
vote
0answers
47 views

How to perform image classification with SemiAutomaticClassificationPlugin and BIP files?

I have multiband satellite images BIP format, Landsat TM/ETM containing 7/8 bands respectively along with a separate header file, some of them corrected by nearest neighbour classifier. I'm working ...
1
vote
1answer
108 views

Floating point calculations in QGIS

How do I manage floating point calculations in QGIS? I have carried out 3 consecutive calculations on landsat bands. I end up with 32 bit floating point rasters on which I can't carry out a 4th ...
5
votes
1answer
882 views

Atmospheric Corrections for Landsat 8 OLI Using Orfeo Toolbox

I am trying to correct some Landsat 8 OLI imagery using the Orfeo Toolbox Optical Calibration tool via QGIS. I've retrieved data from Aeronet as well as relative spectral response data for the OLI ...
0
votes
1answer
121 views

How to export a map (satellite image, 3 bands) to Tiff without losing the resolution in Qgis.

I manually improve the colour contrast of landsat images. The printing in pdf afterwards is OK, as it maintains the resolution due to the high dpi. Now I am interested to obtain a kmz/kml file of the ...
1
vote
1answer
123 views

How to get a the minimum value of a raster layer in qgis with python?

I'm very new user of QGis and I work with landsat 5 images. In this framework, I would like to make an atmospheric correction subtracting the minimum value present in each band (1 to 4). My ...
1
vote
1answer
581 views

Using Landsat 8 for quantitative analysis - what DNs does GRASS require?

Hoping someone can short circuit a lot of exploration Landsat 8 values are stored as unint16 since the sensors work on a range 0 to 4096 whereas the L7+TM was 8 bit and had a digital number range 0 ...
0
votes
0answers
99 views

Saving/exporting a RGB Landsat 8 into a tiff for posterior import into AutoCad

I am familiar with making maps QGis. Generally, I use the print composer and save the RGB satelite image in pdf. However, a client is asking me for a georeferenced tiff to load into autocad. I would ...
3
votes
0answers
72 views

How to analyze the signatures for a Landsat clasification with Sextante in Quantum Gis

I’m defining my training data for a Landsat classification. I´m digitalizing the polygons with the field data in QGis and I want to analyze the signatures of the Landsat images to avoid errors. In ...
5
votes
3answers
362 views

Polygonize vegetation area from Landsat7 RGB using QGis / Bilko?

I'm trying to extract the areas with vegetation as a polygon-shape from a landsat7-image, 30m resolution, RGB, using QGis 1.8 or Bilko or (hopefully in the near future) ArcGIS. The area is in Northern ...
7
votes
1answer
2k views

How to fill gaps in SLC-Off Landsat 7 ETM+ Images with QGIS?

Explanation of the problem: On 31 May 2003 the Landsat 7 Enhanced Thematic Mapper (ETM+) sensor had a failure of the Scan Line Corrector (SLC). Since that time all Landsat ETM+ images have had ...
5
votes
6answers
595 views

Southern hemisphere projections for Landsat upsets GRASS

Hi All does anyone have the last word on why Landsat scenes don't project in the southern hemisphere. This causes no end of trouble in GRASS, less so in QGIS. What I mean is, take an original scene ...