All Questions
545 questions
2
votes
0
answers
69
views
How to create Strips with GCP point distribution for raw GeoEye satellite imagery?
I have raw GeoEye satellite imagery, I just want some guidelines for creating a strip map with GCP distribution. We need to make orthorectification for raw GeoEye satellite imagery, I think it's ...
- 1,123
2
votes
0
answers
1k
views
Why image do not color match when many Landsat images are mosaicked in ERDAS?
When I try to mosaic Landsat images in ERDAS I get as result image with discordance in colors.
I tried histogram matching but no success.
The images were captured between March and May.
- 21
2
votes
0
answers
686
views
Segmentation Image used to classify RGB image in ERDAS and GIS
My ERDAS 2013 does not have the advanced Image Objective Extension for feature extraction..
I am using thus the tool Image Segmentation (Unsupervised -> Image Segmentation) to classify my RGB image ......
- 49
2
votes
0
answers
68
views
"Back calculating" to quantify the "atmospheric effect" of water vapor or other gases in a "corrected" hyperspectral image using QUAC?
I know that when using FLAASH in ENVI, you can produce a water vapor map (caveats considered) from your atmospheric correction.
My question is if it is possible to "back-calculate" a water vapor map ...
- 21
2
votes
0
answers
461
views
Importing GPS coordinates to extract multiple DN values in ERDAS
I have a set of GPS points (stored as a csv for now) and would like to import these points to ERDAS to find the DN values associated with each location.
I am able to import a SHP to ERDAS but the ...
- 53
2
votes
0
answers
398
views
Extract road defects from terrestrial LiDAR, in Erdas 2012 or ArcGIS10.1
I'd like to extract road defects from a lidar point cloud. So, wherever a road surface drops or raises by a few mm relative to 100 cm around it.
I know it's possible but I just can't find or figure ...
- 8,298
2
votes
0
answers
446
views
ENVISAT ASAR .N1 file is not being opened by ERDAS IMAGINE 2011
I am not able to open ENVISAT ASAR .N1 file in ERDAS IMAGINE 2011. The software has direct read option for files of this format. Whenever I try to open the file, software closes automatically giving ...
- 89
2
votes
0
answers
190
views
How to change the order of a raster in order to create mosaic with MosaicPro (Erdas 9.2)?
Is there a way to reorder the input files so I can control which ones are on top of the others?
- 309
2
votes
0
answers
432
views
HCS resolution merge (artifacts and dead pixels)
I try to use ATCOR and HCS resolution merge to preprocess urban Worldview-2 data. Applying the HCS algorithm without initial atmospheric/radiometric correction works just fine, but if I apply ATCOR ...
- 21
2
votes
3
answers
3k
views
Converting Landsat8 DN to TOA reflectance for use in envi
I am used to working in envi, however my current version does not support Landsat8.
I downloaded GRASS for the express purpose of converting Landsat8 DN to TOA reflectance for use/analysis in envi.
...
- 21
2
votes
2
answers
1k
views
How to copy/move Mosaic Dataset to another location?
On my previous question on Mosaic Dataset vs. ERDAS 2011 Is ERDAS 2011 or ArcGIS 10.1 best to use when mosaicking 100's of ECW image files?, I did research for a bit was wondering what happens if you ...
- 4,139
1
vote
4
answers
742
views
Most efficient way to perform rastercalculations with GeoTIFF and/or ErdasImagine files greater than 100gb
I have many GeoTIFFs ranging from 50-300gb and expect I'll have some even larger in the near future. I running a simple subtraction on a pair 77gb 1-band files, but I will also have similar 6-band ...
- 151
1
vote
3
answers
877
views
Extraction of monthly image from two-16 day images?
I need to combine two-16 day NDVI image into monthly NDVI image.
To do this, what kind of function and formula are used in ENVI, ArcGIS Desktop or ERDAS?
- 579
1
vote
2
answers
2k
views
Extract the spectral signature of Landsat 7 and Landsat 8
I have some polygons and I want to extract the spectral signature of the adjacent satellite images. The satellite images that i use are the NDVI from Landsat 7 and 8 and I want to compare the spectral ...
- 3,464
1
vote
2
answers
3k
views
Extract pixels from NDVI in ArcMap
I have a NDVI that I created from a Landsat 5 image. Is there a way to extract all the pixels above a certain threshold and save it as a shapefile? I am trying to create a vegetation mask of sorts to ...
- 165
1
vote
2
answers
90
views
Digitizing photographs of a map
Is it possible to digitize the photographs of very old maps, having no co-ordinates. The photographs are exactly like this. If possible, could somebody tell me how to proceed? I have access to ArcGIS ...
- 13
1
vote
2
answers
310
views
Mask raster cells within only
I am using the Extract by Mask tool in ArcGIS. The tool is extracting all the cell that intersect the masking layer. Is there a process to mask only the cells that fall completely within the making ...
- 601
1
vote
2
answers
704
views
Which one is best for atmospheric correction?
My aim is to determine surface temperature extraction by computing NDVI from Landsat 7 and Landsat 8. suggest me which method DOS (dark object subtraction) or FLAASH atmospheric correction in ENVI ...
- 31
1
vote
2
answers
3k
views
set cells with specific values as NoData in afloating raster
I have a raster file which includes floating values. I need to set cells with specific values as Nodata. For Raster integer values, the setnull tool can be applied, is it any tool for floating point?
...
- 23
1
vote
1
answer
1k
views
Spectral mixture analysis from GeoTIFF in ENVI
I have a single GeoTIFF created from some NGB aerial photography that has been stitched in Agisoft Photoscan to create a single image of an area of heath.
I would like to perform spectral mixture ...
- 137
1
vote
2
answers
5k
views
How to determine soil moisture index values from reflectance values in a satellite image?
I'm working on determination of soil moisture by remote sensing. I would like to know how we can determine soil moisture index values from reflectance values in LANDSAT TM images.
- 89
1
vote
1
answer
4k
views
ENVI Vegetation Index Calculator
I am attempting to input 4-band CIR imagery into ENVI's Vegetation Index Calculator and keep running into the same error: "Wavelengths must be defined to calculate vegetation indices".
I have ...
- 51.8k
1
vote
1
answer
771
views
Calculating latitude and longitude values for each pixel corner?
I have a TIFF image file and I need to extract the latitude and longitude values (in decimal degrees) for each pixel's corners. I have the latitude and longitude values for the top right, top left , ...
- 209
1
vote
2
answers
409
views
Activating swipe tool in ERDAS imagine?
I am having a problem trying to enable (activate) the swipe tool in ERDAS imagine.
I used to use it but due to some reason the tool is deactivated.
Is there a way?
- 11
1
vote
1
answer
883
views
Pro vs Con on using export to JPEG or JP2000 files for large imagery files
What is the preference among GIS Specialist and Remote Sensing Specialist using the JPEG vs JP2000.
Yes, I am aware of other compressed files such as ECW or MrSID...
I am more of concern of how to ...
- 4,139
1
vote
2
answers
3k
views
Using MODIS Data after FLAASH
I need to convert modis MOD021km data to reflectance and Brightness temperature.
I know that some plugins for Envi is doing this with modis data but I want to run an atmospheric correction on my data ...
- 625
1
vote
1
answer
3k
views
How to rescale data ranges in ERDAS?
I have an Normalized Difference Vegetation Index(NDVI) and Enhanced vegetation index (EVI) layer and I want to re-scale their data ranges to value ranges from 0–to–1, in order to optimally stretch the ...
1
vote
1
answer
2k
views
Processing MOD35_L2 HDF Cloud Masks
I am attempting to create a binary cloud mask from the MOD35_L2 data products located at http://ladsweb.nascom.nasa.gov/data/ When opening the MOD35_L2 data in ENVI or the MRTSwath tool it reports 6 ...
- 13
1
vote
1
answer
3k
views
Converting ERDAS (*.img) file into headerless binary file?
I am having trouble converting an ERDAS (*.img) file into a headerless binary file.
I want to use those images in the TIMESAT program.
I'm trying to do this in IDRISI 32 but there is an error ...
- 659
1
vote
1
answer
867
views
GeoTIFF to ENVI GDAL translation causes rotation
I have a GeoTIFF(you can download it here ~16MB) which I want to convert to ENVI raw. I'm using this GDAL command:
gdal_translate -ot UInt16 -scale -of ENVI -outsize 1025 1025 dgm1_32372_5680_2_nw.tif ...
- 157
1
vote
1
answer
478
views
Masking an image in Erdas using Thematic Image, the mask comes out looking wrong and completely different than input image
I am trying to mask out shadows and clouds in a WV2 8-band image. I classified an image to identify the shadows and clouds and then using the mask took in erdas used the classified image to mask out ...
- 31
1
vote
1
answer
379
views
Histograms in Erdas Imagine staying grey
When I open the metadata in Erdas Imagine 2016 of a raster file (I tried several different raster files) the histogram at the histogram button stays grey. I already tried to change the setting of NAs ...
- 317
1
vote
1
answer
3k
views
How to open a Higher Level Landsat image with ENVI 5.2?
A mistake every time I try to open the .MTL archive. The error that appears says "File does not appear to be a valid TIFF file". The archive's size it's smaller than it should be. Is there's any ...
- 11
1
vote
1
answer
1k
views
calculate NDVI for several images
I want to calculate NDVI for 50 Landsat 7-TM images . I have done a stack layer for each band of 50 images using envi software and then calculate NDVI for the stack of two bands demanded in NDVI ...
- 19
1
vote
1
answer
203
views
How to keep the georeferencing data from ArcGIS when importing rasters into Erdas imagine?
I have a bunch of WWII Aerial images that I georeferenced in ArcMap and when I load them in Imagine they are being displayed as plain rasters. I tried the Import Data tool, converted the georeferenced ...
- 618
1
vote
1
answer
1k
views
Doing supervised classification for images on ERDAS?
i want to do a supervised classification for images on ERDAS, using GIS, i clipped the areas i want to use as training/signature from the original images. but i just can't create a signature file, ...
- 21
1
vote
2
answers
186
views
Modis MOD11A1 band math expression
I am trying to calculate the temperature of MOD11A1 and I can't find the expression of band math. How the expression temp < 273 could be written at band math?
- 11
1
vote
1
answer
255
views
How to create a map from separate ascii files without merging them?
I have three ascii files including longitudes, latitudes and pixel values. I just wonder whether there is anyway to display a map from the three files and save it in geotiff without merging them into ...
- 11
1
vote
1
answer
974
views
Black edge (NoData pixels) in Landsat 8 color correction in ERDAS
My boss asked me to mosaic and color-balance multiple Landsat 8 tiles for presentation. I tried to do that in ERDAS but it returned weird result as below:
Obviously it's the black edges or nodata ...
- 333
1
vote
1
answer
1k
views
Parameter names and meaning of their values in an ENVI header file
This is the header of an Envi file:
ENVI
description = {
PolSARpro File Imported to ENVI}
samples = 8407
lines = 5569
bands = 1
header offset = 0
file type = ENVI Standard
data type = 4
...
- 731
1
vote
2
answers
1k
views
land Use land cover classification [closed]
I am working on Land Use/Land Cover Classification of the Hindon river(India) watershed extracted using Aster DEM. Landsat 8 scenes had been used and mosaicked for the required AOI using the Watershed ...
1
vote
1
answer
1k
views
Pixel Value in a Lat and Long location in Envi IDL
I am new with ENVI IDL,I want to get pixel value of each band in an image in specified lat and long location.I can do a loop among bands in image using this code
ENVI_OPEN_FILE,'E:\MASTER\Payan_Name\...
- 625
1
vote
1
answer
756
views
Does MOD021km images from MODIS needs atmospheric corrections
I have downloaded some mod021km modis images and I want to work with them.
I want to know if these data need atmospheric corrections?
Perhaps something like FLASSH in ENVI or other methods.
I can ...
- 625
1
vote
1
answer
949
views
Could not open/read USGS raster file
I could not open/read the following .img file.
The document below says it is a raster file.
http://edc2.usgs.gov/1KM/land_sea_mask.php
I tried to open it using many ways such as Q-Gis software, and ...
- 179
1
vote
1
answer
1k
views
DN to TOA reflectance for SPOT images using Erdas Imagine
I would like to convert DN to TOA reflectance in Erdas Imagine 2013. I see there is a way of doing this for Landsat7 in the Radiometric tab.
How can I do this for SPOT2,4,5 images?
- 129
1
vote
1
answer
325
views
Problems using ATCOR for Erdas Imagine '13
An output from ATCOR processing (besides an atmospheric correction and dehazing) is expected to be an image containing true reflectance values (instead of raw input DNs). As far as I know such data ...
- 3,593
1
vote
1
answer
1k
views
How to create an Erdas batch list file (.bls) using Python?
How can I generate the Erdas batch list file (.blf) using Python? For example, I want to run a 5x5 median filter in the Batch Command Editor using a subset of images within a folder. Erdas provides ...
- 51.8k
1
vote
1
answer
196
views
Creating training areas for parametric classifcation
I am creating a signature file for a supervised classification for a subset of a LANDSAT image. I know what classes I would like to create, and have identified ideal areas for training. However, I am ...
- 53
1
vote
2
answers
2k
views
How to remove sandy dots in an image?
I am processing a LandSAT image for geological purposes. After some processing there are so many sandy dots in the image. To get clear geological formation as a polygon I want to remove small sandy ...
- 379
1
vote
3
answers
814
views
problems of display modis ndvi with TIMESAT
I use MODIS MRT tool mosicia tow tiles MODIS NDVI data, then use TIMESAT image view to display the mosaic data, encounting file size waring :
and after drawing data, the sequences of two tiles is ...
- 51