Custom Query (432 matches)
Results (346 - 348 of 432)
Ticket |
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#71 |
Description |
Dear Ivana, My name is Elena Prado and I am a user to azgcorr. I have some questions for you, I try to geocorrect CASI images to achieve L3 product. The images were acquired over Guadalajara (Spain). Datum transformation I am using azgcorr with the option of 7 parameters for datum transformation; the parameters are specially adapted to the flight zone. But when I check the results, the images have an offsets in coordinates (offset in Xutm = 104 offset in Yutm = 132). I know that the images are synchronized with the navigation data because the effects of the aircraft movement have been removed correctly. The offset in Xutm fit with the difference between WGS84 and European Datum 1950 so I am not sure that the azcorr makes the transformation. I send you the azgcorr command line: > azgcorr -p 3.5 3.5 –bl 45 15 5 -1 –d7 0 131.032 100.251 163.354 -1.2438 -0.0195 -1.1436 -9.39 –mUTM -3 –eh /MDT25_IGN_GUADA_ED50_3m_he.txt –es NO –ua 0 0 -0.465 –ut -59.995 -1 /c154011b.hdf -3 /c154013_ed50.hdf -p 3.5 3.5 : pixel size 3.5 meters -bl 45 15 5 -1 CASI bands to georeference 45/15/05 –d7 0 131.032 100.251 163.354 -1.2438 -0.0195 -1.1436 -9.39: seven parameters for datum transformation -mUTM -3 : UTM projection zone 30. (central meridian longitude -3) -eh : DEM file in UTM H30 ED50 and ellipsoidal height -es NO : no geoid undulation -ua 0 0 0.465 : offset in heading to apply the meridian convergence -ut -59.995: offset to correct the synchronization between image and navigation data Can you help me with the Datum transformation? ENVI header I use the azexhdf to get a Envi header. > azexhdf –h /c154013_ed50.hdf –Be /c154013_ed50.bil I get a BIL format image with this command line and in other folder (I don’t know why azexhdf doesn’t write in the same folder) get another file P9.hdr with the Envi header. But the map info in the header is not correct. The datum of the L3 image doesn’t appear in the header file and the coordinate of the header is the SW image corner coordinate instead of NW image coordinate that ENVI needs. Map info = {UTM, 1, 1, 562233.00, 4518052.00, 3.50, 3.50, 30, North} Do you know how I can solve this? Image line start – line end I detect that the data have a des-synchronization between the image and navigation data, this time offset is 59 seconds more or less This time is equivalent to 909 lines from the first line in the image L1b. I think that with this scan timing offset (-ut -59.995) the synchronization is ok, so I don’t know how use the information about the scan line (start / end) number information. Can I do without these?? Data extracted from c154011b.hdf MIsscan: 248 MIsescan: 6009 NVscnum 248 -> 6009 CAsscan: 248 CAescan: 6010 COsscan: 248 COescan: 4205 COscans: 3958 Thanks you very much, Elena Prado Ortega <Contact details removed, see internal contact details page> MailScanner has detected a possible fraud attempt from "correo.uah.es" claiming to be http://www.geogra.uah.es/teledeteccion-ambiental ___________________________________________________________________ Este mensaje se dirige exclusivamente a su destinatario y puede contener información privilegiada o CONFIDENCIAL. Si vd. no es la persona a quien se dirige este mensaje, queda notificado de que la utilización, divulgación y/o copia sin autorización está prohibida en virtud de la legislación vigente. Si ha recibido este mensaje por error, le rogamos que nos lo comunique inmediatamente por esta misma vía y proceda a su destrucción. This message is intended exclusively for its addressee and may contain information that is CONFIDENTIAL and protected by professional privilege. If you are not the intended recipient you are hereby notified that any dissemination, copy or disclosure of this communication is strictly prohibited by law. If this message has been received in error, please immediately notify us via e-mail and delete it. |
#73 |
Description |
Many 2007 flight lines have problems with navigation sync (ie. they don't sync!). This appears to be due to missing sync messages in the .nav file, or a totally missing .nav file. A typical error looks like: -------------------------------------------------------------------------- azimport -- ver: 2.2.10 May 7 2007 (C) Azimuth Systems UK 1996, 2007 File template for Specim sync is: hawk/SWIRsh2007130#.nav Site time limits - day: 130 start: 94341 end: 94609 date: 10 05 2007 jday: 130 utc2gps: 14.0 NAV vgroup exists - updating Specim navigation sync details from image file header..... image lines: 2901 approximate sync time: 35021.46880 (gps SoD) frame inc: 0.05000 secs sensor: Hawk frame rate: 20.00 fps no. of frames to correct for: 3.00 sync time: 35021.5 is NOT on Applanix POSATT file: hawk/SWIRsh2007130a-1.nav start: 35182.8 end: 35403.5 sync time: 35021.5 is NOT on Applanix POSATT file: hawk/SWIRsh2007130a-2.nav start: 35421.1 end: 35565.1 sync time: 35021.5 is NOT on Applanix POSATT file: hawk/SWIRsh2007130a-3.nav start: 35752.3 end: 35869.1 sync time: 35021.5 is NOT on Applanix POSATT file: hawk/SWIRsh2007130a-4.nav start: 36085.1 end: 36243.4 ** NO Specim SYNC found after checking all files ** check file template and directory contents - no data saved A procedure to correct for this is outlined in the specim processing guide but appears only to apply to azspec 1.1.3. We have azspec 1.1.2. |
#74 |
Description |
Rachel contacted us with a problem relating to radiometric calibration. I'm not sure who specifically is the best person to ask about this, but I am having some problems with the AISA Eagle data recently delivered for my sites (Clocaenog and Glasfynydd, acquired July 06). The radiance values differ considerably to those of the CASI and ATM data acquired at the same time, specifically they are much lower (about 1/2 to 2/3) in the Eagle data (see attached spectra of a paved area in Glasfynydd for an example). Following attempts at atmospheric correction, this results in significantly lower reflectance than is expected based on ground spectra. I may be missing something obvious (e.g. different units), or is this down to errors in the radiometric calibration of the Eagle sensor? |
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