.. index:: ! asa_im_decode ************* asa_im_decode ************* Synopsis -------- **asa_im_decode** * * Description ----------- **asa_im_decode** Decodes Envisat ASAR Image Mode Level 0 data. *asa_im_decode v1.1 by smb* Required Arguments ------------------ *asa_im* Input image file(s) (multiple files if merging along-track) *asa_ins* Input auxilary instrument characterization data file *out* Output raw data file. **out** is a complex file with no headers (byte/float I1, byte/float Q1, byte/float I2, byte/float Q2, ...) *outType* Output file type (1=byte,4=float). If outType is byte, then the decoded floats are multiplied by 127.5, shifted by 127.5, rounded to the nearest integer and limited to the range 0-255. *near_range* Near range to which to align all lines (0=use first line near range) Notes ----- Starting range computed as (rank*pri+windowStartTime)*c/2 where rank is the number of pri between transmitted pulse and return echo Calibration/noise lines are replaced with previous echo data line Missing lines within a data set and between adjacent along-track data sets are filled with zeroes in float mode and 0.*127.5+127.5 + .5 = 128 for byte mode Auxilary data files can be found at http://envisat.esa.int/services/auxiliary_data/asar/ Envisat ASAR Product Handbook, Issue 1.1, 1 December 2002 can be found at http://envisat.esa.int/dataproducts/asar/CNTR6-3-6.htm#eph.asar.asardf.0pASA_IM__0P Example ------- :: asa_im_decode