Lurker Posted July 22, 2011 Report Share Posted July 22, 2011 Hello , I have PALSAR that need to extract DEM data, the problem is that I never touch SAR data :grin: okay, right now, I use ENVI Sarscape, and able to import and focusing PALSAR data (it said that raw SAR data need to be focused to make SLC data) then, the next step is DEM extraction, how I can do that? okay mate need some direction and tutorial bout this, any kind of software, not necessary ENVI, will be accepted waiting 1 Quote Link to comment Share on other sites More sharing options...
pasfans01 Posted July 23, 2011 Report Share Posted July 23, 2011 you want to do stereoscopic or interferometric DEM extraction mod ? hehe Quote Link to comment Share on other sites More sharing options...
Lurker Posted July 23, 2011 Author Report Share Posted July 23, 2011 hem, for stereoscopic, i think we need stereoscop SAR data, am I correct? I dont have it, so I think interferometric DEM Extraction will suites for me please guide us regards, MOD Quote Link to comment Share on other sites More sharing options...
pasfans01 Posted July 23, 2011 Report Share Posted July 23, 2011 I cant help if it was interferometric DEM that u want to extract, yes, Stereoscopic DEM extraction need at least two SAR images covering the same area but at different angle, and interferometric DEM need at least two SAR data that have different phase or polarization (CMIIW), I dont have any experiences about interferometric processing, but ERDAS Imagine have module and tool to do it, IMAGINE INSAR, have you look it? Quote Link to comment Share on other sites More sharing options...
Lurker Posted July 23, 2011 Author Report Share Posted July 23, 2011 ah, so it need another SAR data with different spec, hem I see that, Okay, this the real work I need to solve with SAR data I need to now the exact volume of sediment after volcano eruption, the data is PALSAR data, I have been manage my PALSAR data, inside the packages there is HV and HH data and after focusing and import (I assume that my data is RAW data , since i saw H-1 in the name of the file) i got 2 SLC SAR data, is it correct ? I have this PALSAR data before and after the eruption, each packages contain 2 different image (HH and HV) so what is the best method to get the DEM ? regards, MOD Quote Link to comment Share on other sites More sharing options...
pasfans01 Posted July 23, 2011 Report Share Posted July 23, 2011 I think you can try both Mod, ERDAS has tools to do both, If you want to use stereoscopic, You can use IMAGINE Stereo SAR DEM extraction module, and for interferometric, you can use IMAGINE INSAR DEM extraction module, to do stereoscopic processing,U must have 2 images at different date or angle (not polarization, sorry), but viewing the same areas, U can try using pre and post disaster images to do stereoscopic modelling and extract the DEM, the disadvantages of stereoscopic is, you will need many high quality GCPs in order to extract Absolute DEM, the GCPs will be used to model the sensor geometry,calculate the paralax, then onvert the paralax image to elevation using height data from the GCPs, at stereoscopic side, the problem about your data is, if you have only 2 datasets (pre and post disaster), I am afraid the landcover and terrain condition of the study area has been changed due to the disaster, so at those kind of landcover/terrain, paralax generation will fail, and DEM creation will fail too at that kind of area, stereoscopic processing need the landcover/terrain not too changed or just slightly changed, so epipolar image generation could be done by the software, and paralax could be computed, I am not really sure about interferometric processing, because I dont have any experinces about it but I suggest you try it using multipolarization data (HH and HV) at same date, interferometric principles actually pretty much same with stereoscopic principles, but it use differences radar range/signal travel time instead of stereo geometry (stereoscopic approach). interferometric processing will result interferogram that correspond with elevation differences of earth surface, and using one or two high quality GCPs as the datum, the resulted interferogram can be converted into DEM, at the interferometric side, you just need one or two GCPs functioned as elevation datum, and I think your data is fulfill this kind of operation, you can use HH and HV data of pre disaster images to create pre disaster DEM, HH and HV data of post disaster images to create post disaster DEM, and then compare both of them to calculate the sediment, Quote Link to comment Share on other sites More sharing options...
Lurker Posted July 24, 2011 Author Report Share Posted July 24, 2011 oh yeah, I think I will do interferometric processing hem, if you have any paper or maybe tutorial step by step for any kind of software let me know this SAR terminology is really strange in my ears, ahahahaha regards, MOD Quote Link to comment Share on other sites More sharing options...
pasfans01 Posted July 25, 2011 Report Share Posted July 25, 2011 use ERDAS IMAGINE INSAR DEM mod, they have nice tutorial at their help resources, may be it can help a bit, hehe Quote Link to comment Share on other sites More sharing options...
Lurker Posted July 28, 2011 Author Report Share Posted July 28, 2011 hem, yeah, right now, I try different kind of software, from ERDAS, ENVI, NEST, Map Ready, PolSARPro, and etc etc hehehehehehe, any step by step please? anykind of software will do regards, MOD Quote Link to comment Share on other sites More sharing options...
peralta2794 Posted February 20, 2015 Report Share Posted February 20, 2015 How did it go with the process of ALOS / PALSAR? Quote Link to comment Share on other sites More sharing options...
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