6

An RPC model is the ratio of two polynomials which can be derived from the rigorous sensor model and the corresponding terrain information, which does not reveal the sensor parameters. High resolution satellite image vendors provide a RPC file with the image. This file consist of RPC coefficients which is used to relate coordinate in a sensor plane (2D) to ...


5

Answer for others so confused people as I am: To know how to deal with downloaded raw Landsat data - what else in pre-processing do I need? Firstly check their processing level in_MTL.txt file (included in downloaded Landsat image: http://landsat.usgs.gov/Landsat_Processing_Details.php) Processing level = DATA_TYPE L1T - terrain corrected processing. ...


4

Unfortunately, it turns out at this time, GDAL does NOT support OPENCL speed up on orthorectification. In fact, the only speedup I have been able to find is that compiling with OpenCL does speed up resampling slightly. This would be a good feature for GDAL to implement at a future date.


4

Photoscan maybe a better choice. You could download a 30 days trial version from http://www.agisoft.com/


4

You can use GRASS GIS 6 for orthorectification of aerial photos (UAV should work the same). See for related instructions: http://grasswiki.osgeo.org/wiki/Orthorectification_digital_camera Orthorectification chapter from the GRASS GIS book


4

Orthorectification is the process of correcting aerial or orbital images for terrain geometry. The terrain geometry is given by a DEM (a DTM in the case of regular orthophotos, high-resolution DSM for true orthophotos), though you need a lot more than just that (for example, you need ground control points, camera calibration parameters, flight data, etc.). ...


4

According to the QImagery help-page, you should try EPSG:3857 (Pseudo Mercator). In addition you must tell QGIS which CRS to use. From the top menu, choose Settings – Options and the CRS-tab. Choose e.g. the option "Prompt for CRS" when a layer is loaded that has no CRS (or "USe project CRS" if you have set the project CRS to be 3857 in beforehand). QGIS ...


3

In my work I encounter this situation often. The method that I use is next: Prepare the images in Photoshop: crop, contrast, brightness, whatever is needed to improved image quality. Also in Photoshop use the Photomerge tool from File->Automate->Photomerge. Keep "Blend images" checked. After testing it seems that the "Auto" method yields the best results ...


3

To add to Erik's comment, I believe I've also heard it referred to as a "contact sheet". https://www.picturesandstories.com/news/2014/2/24/how-to-print-a-contact-sheet-of-photos-in-windows Also, CALTRANS has a nice write-up of what they consider a Photo Index to be. http://www.dot.ca.gov/hq/esc/photogrammetry/resources/Aerial_Photo_Index_Guide_2013v1.pdf


3

You need additional parameters from the image acquisition process. Important are: sensor resolution which is the cellsize of the chip, the sensor area and the focal length. Normally you need also correction factors to compensate the spherical errors of your lenses. You should ask for the camera type and try to find these parameters in the web. Cellsize,...


3

If you run gdalinfo you'll notise that GDAL does recognize .jpgw as a World file. gdalinfo QAP27863800.JPG Driver: JPEG/JPEG JFIF Files: QAP27863800.JPG QAP27863800.jpgw Size is 3800, 4000 GeoTransform = 15923663.02324857, 0.6464472699464198, 0.004029513396384988 -1123438.005344422, 0.004072074029169209, -0.6506963195161204 Metadata: ...


2

Since your data is already in UTM 34N projection, all you have to do is reproject it to your local CRS. You can do this with gdalwarp (even in batch mode for a whole folder), or inside QGIS with Raster -> Projections -> Warp . ARCGIS should offer similar tools. So no need for georeferencing manually.


2

While I understand it is about pricing and the cost but have you looked at it here http://www.ips-match.com/ I myself have not tried this since I only use ERDAS or ENVI. You can try and google "Orthophotos software" and it came up a few software that might be free or commerical. One thing I attend ERSI's Dronemap and really nice program they had and you ...


2

What you see if the effect of the camera's central projection (the image is projected through the camera's focal point). This means that there is a radial distortion where protruding objects in the images appear to lean away from the center. This is direct effect of object height and the distance from image nadir (center). The production of so-called "true ...


2

From https://trac.osgeo.org/grass/browser/grass/branches/releasebranch_7_2/imagery/i.ortho.photo/README?rev=69510 : STATUS: The i.ortho.photo suite of modules has been temporarily disabled from GRASS 7 as they are heavily dependent on the text-based Vask libary and interactive XDRIVER monitors, both of which have been removed....


2

In most processing chains, orthorectification or reprojection is performed as late as possible in the workflow, to avoid altering the spatial relationships between neighbouring pixels. In your case, re-sampling first would alter the value of pixels say, at the interface between a water body and land, which would then lead to incorrect estimates in the ...


2

OTB do include test for support of WV3 geometry. I supposed that the format is pretty much the same as WV2 which explain why the process run without errors. Nevertheless there is still a bit of work to check that the orthorectification is correct Even if it's not a quantitative validation (sensor modelling validation can be tricky question) you should try ...


2

I recommend that you copy/paste the issue on the OTB gitlab issue tracker. https://gitlab.orfeo-toolbox.org/orfeotoolbox/otb/issues It will notify all otb developers and increase chances that somebody looks at this issue. Looking at your message, I think that there is indeed an issue on OTB side.


2

Imagine your image is a flat piece of paper and you are trying to attach it to the surface of a spherical object with as little folds/wrinkles in the paper as possible by pressing push pins through the paper and into the sphere (these are your control points). You could exclusively add a bunch of push pins to the middle of the page, this will do a good job ...


2

With RS2 you need to point GDAL to either the parent directory or the product.xml file. From your code, you are pointing to the *.tiff file directly. So your modified code should be: gdalwarp -overwrite -s_srs EPSG:4326 -t_srs EPSG:4326 -rpc -to RPC_DEM=dem.tif product.xml out.tiff Also, if you run gdalinfo on the product.xml you will see the RPC ...


2

You can try the USGS data portal: https://earthexplorer.usgs.gov/ I have acquired data below 4 m from the site. You use their search tool and select what you are interested in and apply the proper filters. You can also use the national map to source other data from the US https://www.usgs.gov/core-science-systems/national-geospatial-program/national-map.


2

It's hard to answer this question without seeing the images, but I'll try. For orthorectification, you need to know internal orientation, deduced from the camera, and external orientation parameters. Forget about this variant in your case. If your mountainous area contains remarkable reference points (such as road crossings, free-standing trees, big ...


2

Did you install everything cleanly using OSGEO4W? This module is also on my QGIS but the executable is present in the GRASS folder of QGIS. C:\Program Files\QGIS 3.4\apps\grass76\bin You could try using the command line executable. The syntax is as follows: https://grass.osgeo.org/grass76/manuals/i.ortho.rectify.html


1

Years ago when I did Photogrammetry you looked for tie points. These were just points that were identified on two or more photos, to build a photo model. We used points that were on sharp features like a roof corner or any sharp edge. Once we had points to hold our model together, we use GCP to tie the model to the earth/map. Basically these were easily ...


1

You could try AROP from USDA. This is not open source, but free and working in command lines on Linux, so it has the features that you are looking for. Reference Gao., F., Masek, J. G., Wolfe, R. F., An automated registration and orthorectification package for Landsat and Landsat-like data processing, Journal of Applied Remote Sensing, Vol.3, 033515, doi: ...


1

I came across AROSICS, or An Automated and Robust Open-Source Image Co-Registration Software for Multi-Sensor Satellite Data by Daniel Scheffler, which is a python library and command line tools for warping one (roughly) georeferenced image to a reference image: https://pypi.python.org/pypi/arosics/0.8.0 The python library gives you access to the tie ...


1

RMSE represents the square root of the average of the set of squared differences between elevation model coordinates and ground truth - that is, the control elevation model or raster to which you are orthorectifying your older aerial photos. What this means, essentially, is that the RMSE represents an averaged difference from your rectified imagery to where ...


1

Here is the command I use to do it all at once, plus some other helpful settings to help it run a bit quicker. If needed, you can also specify coordinates to chip the image using the -te flag. This command will chip the image, change the output format, and orthorectify using a DEM in a single step. You can download SRTM here: http://srtm.csi.cgiar.org/...


1

This will not help you in ArcMap but ArcGIS Pro (which is part of the ArcGIS Desktop license) will be worth investigating for Georeferencing a raster automatically to another raster: Auto Georeference allows you to automatically georeference your raster dataset to a referenced raster dataset. The automated control points are based on the spectral ...


1

I would try to add a low resolution DEM (e.g. SRTM 30m) to fill the gaps where your high resolution DEM is not available. The problem with a crop before orthorectification is that the RPC link image coordinates with ground, so if your image is not georeferenced and you crop it, this relationship will be detroyed.


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