Oxford MIPAS L1C format


L1C files are generated by the IDL program l1c.pro and consist of microwindows extracted from ESA L1B files which have had the Norton-Beer 'strong' apodisation applied.

Since the format of these files may change as the requirements are further refined this web-page will describe each different format.

Provided data is read free-format (apart from the 8-character microwindow label) decimal changes in format version should not cause problems (so, for example, anything written to read v1.0 should also work for v1.2, but not necessarily v2.0).


L1C format 2.1

Generated by other software adapted from MIPAS L1C, 3 May 2012 onwards.
Difference from v2.0 is the provision for a new spectrum type = 4. If this type is selected then there are some other changes in the format (but no changes if the type = 1,2 or 3) Changes from v2.0 highlighted in blue

Example:

! L1C file generated by l1c_str.pro v.03MAY12
! Microwindows extract from MIPAS-STR spectra
! L1C FORMAT: http://www.atm.ox.ac.uk/group/mipas/L1C/
2.1
    4  0.0360    (new Type 4 defined))
  15.6 0.2     (NB extra record added)
         14
 3721  27188  20100310  073308      0      8.7742     80.0370
    1   10.0888   15.1760   68.7700   21.0200  6396.7676   8    12.992  14.696
PTHO8001      57     756.7964     758.8124       22.4391
   138.81129       219.98285       190.62961       230.47946       547.95811
...
Format changes specific to type 4:
Spectrum type (1=limb radiance, 2=limb transmittance, 3=nadir radiance,
4=internal radiance), resolution [cm-1]
 Obs.Alt [km], Obs.Alt SD [km]
NSweeps in this file
date# [days], time in Day [seconds], date (yyyymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#1
sweep#, Elev. [deg], alt [km], lat, long, radcrv[km], NMic, radcld, cldidx
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#1
p1, p2, ... spectral points in MW#1
MWlabel, npt, wno1, wno2, NESR for MW#2 in sweep#1
p1, p2, ... spectral points in MW#2
 etc ... 
date# [days], time in Day [seconds], date (yymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#2
sweep#, alt[km], alt_nom[km], lat, long, radcrv[km], NMic, radcld, cldidx
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#2
 etc ...

L1C format 2.0

Generated by l1c v.23MAY05 onwards.
Difference from v1.5 is the addition of an extra record after the format identifier to give type of spectrum and resolution. Also, "alt_nom" also copes with 27-sweep "nominal" scans inaugurated in Dec 2004. Changes from previous version highlighted in red

Example:

! L1C file generated by l1c.pro v.23MAY05 on Mon May 23 16:08:55
! L1B FILE: MIP_NL__1P_20405_072642_0504_new_ANX_020513
! L1C FORMAT: http://www.atm.ox.ac.uk/group/mipas/L1C/
2.0
    1    0.0250
   17
  825  26807  20020405  072647    504     10.2744     63.8988
    1   68.1554   68.0000   67.4756   43.1906  6390.1534   1    -4.801   1.826
PT__0001     121     686.400     689.400       79.7898
      -66.482567      -8.0714254       10.095518       71.124718
       187.55252       195.25378       105.31895       73.163322
...
Format:
! Comment records (starting with '!')
L1C format identifier (real number)
Spectrum type (1=limb radiance, 2=limb transmittance, 3=nadir radiance), resolution [cm-1]
NSweeps in this file
date# [days], time in Day [seconds], date (yyyymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#1
sweep#, alt [km], alt_nom [km], lat, long, radcrv[km], NMic, radcld, cldidx
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#1
p1, p2, ... spectral points in MW#1
MWlabel, npt, wno1, wno2, NESR for MW#2 in sweep#1
p1, p2, ... spectral points in MW#2
 etc ... 
date# [days], time in Day [seconds], date (yymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#2
sweep#, alt[km], alt_nom[km], lat, long, radcrv[km], NMic, radcld, cldidx
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#2
 etc ...

L1C format 1.5

Generated by l1c v.07DEC04 onwards.
Difference from v1.4 is that the empty "err on alt" field is now replaced by the nominal altitude "alt_nom", assuming it is one of the standard 17-sweep scans. Changes from previous version highlighted in red

Example:

! L1C file generated by l1c.pro v.07DEC04 on Tue Dec  7 16:08:55
! L1B FILE: MIP_NL__1P_20405_072642_0504_new_ANX_020513
! L1C FORMAT: http://www.atm.ox.ac.uk/group/mipas/L1C/
1.5
   17
  825  26807  20020405  072647    504     10.2744     63.8988
    1   68.1554   68.0000   67.4756   43.1906  6390.1534   1    -4.801   1.826
PT__0001     121     686.400     689.400       79.7898
      -66.482567      -8.0714254       10.095518       71.124718
       187.55252       195.25378       105.31895       73.163322
...
Format:
! Comment records (starting with '!')
L1C format identifier (real number)
NSweeps in this file
date# [days], time in Day [seconds], date (yyyymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#1
sweep#, alt [km], alt_nom[km], lat, long, radcrv[km], NMic, radcld, cldidx
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#1
p1, p2, ... spectral points in MW#1
MWlabel, npt, wno1, wno2, NESR for MW#2 in sweep#1
p1, p2, ... spectral points in MW#2
 etc ... 
date# [days], time in Day [seconds], date (yymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#2
sweep#, alt[km], alt_nom[km], lat, long, radcrv[km], NMic, radcld, cldidx
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#2
 etc ...

L1C format 1.4

Generated by LV2PP v.02FEB04 onwards. (NB earlier version of 1.4 from 17NOV04 had >80 characters in the sweep#, alt, etc record).
Difference from v1.3 is that each tangent height has an additional parameter cldidx added to the 2nd (Sweep# etc) record. This is the U.Leicester Cloud Index based on the ratio of radiance of two specific A Band microwindows, as used in the ESA operational processor cloud-detection. Changes from previous version highlighted in red

Example:

! L1C file generated by LV2PP v.02FEB04 on Tue Feb  3 12:43:28
! L1B FILE: MIP_NL__1P_20405_072642_0504_new_ANX_020513
! L1C FORMAT: http://www.atm.ox.ac.uk/group/mipas/L1C/
1.4
   17
  825  26807  20020405  072647    504     10.2744     63.8988
    1   68.1554    0.0000   67.4756   43.1906  6390.1534   1    -4.801   1.826
PT__0001     121     686.400     689.400       79.7898
      -66.482567      -8.0714254       10.095518       71.124718
       187.55252       195.25378       105.31895       73.163322
...
Format:
! Comment records (starting with '!')
L1C format identifier (real number)
NSweeps in this file
date# [days], time in Day [seconds], date (yyyymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#1
sweep#, alt, err on alt, lat, long, radcrv, NMic, radcld, cldidx
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#1
p1, p2, ... spectral points in MW#1
MWlabel, npt, wno1, wno2, NESR for MW#2 in sweep#1
p1, p2, ... spectral points in MW#2
 etc ... 
date# [days], time in Day [seconds], date (yymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#2
sweep#, alt[km], err on alt[km], lat, long, radcrv[km], NMic, radcld, cldidx
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#2
 etc ...

L1C format 1.3

Generated by LV2PP v.09OCT02 onwards. Difference from v1.2 is that each tangent height has an additional parameter radcld added to the 2nd (Sweep# etc) record. This is the radiance of the apodised spectrum at 960.7cm-1, assumed to be the optically thinnest part of the spectrum hence most sensitive to cloud contamination. Changes from previous version highlighted in red

Example:

! L1C file generated by LV2PP v.09OCT02 on Wed Oct  9 12:35:09
! L1B FILE: MIP_NL__1P_20405_072642_0504_new_ANX_020513
! L1C FORMAT: http://www.atm.ox.ac.uk/group/mipas/L1C/
1.3
   17
  825  26807  20020405  072647    504     10.2744     63.8988
    1     68.1554      0.0000     67.4756     43.1906   6390.1534    4    -4.801
O3__0001     121    1122.800    1125.800       13.1525
      0.29832527     -0.55485380      0.58444756      -6.2133970
      -5.6969886       2.2316978      0.62020731      0.45567566
... 
Format:
! Comment records (starting with '!')
L1C format identifier (real number)
NSweeps in this file
date# [days], time in Day [seconds], date (yyyymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#1
sweep#, alt, err on alt, lat, long, radcrv, NMic, radcld
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#1
p1, p2, ... spectral points in MW#1
MWlabel, npt, wno1, wno2, NESR for MW#2 in sweep#1
p1, p2, ... spectral points in MW#2
 etc ... 
date# [days], time in Day [seconds], date (yymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#2
sweep#, alt[km], err on alt[km], lat, long, radcrv[km], NMic, radcld
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#2
 etc ...

L1C format 1.2

Generated by LV2PP v.26AUG02 onwards. Difference from v1.1 is that radiances are now written free-format rather than 8F10.4 to avoid problems reading values >9999.9999. Changes from previous version highlighted in red

Example:

! L1C file generated by LV2PP v.26AUG02 on Mon Aug 26 10:32:00
! L1B FILE: MIP_NL__1P_20405_072642_0504_new_ANX_020513
! L1C FORMAT: http://www.atm.ox.ac.uk/group/mipas/L1C/
1.2
   17
  825  26807  20020405  072647    504     10.2744     63.8988
    1     68.1554      0.0000     67.4756     43.1906   6390.1534    4
O3__0001     121    1122.800    1125.800       13.1525
      0.29832527     -0.55485380      0.58444756      -6.2133970
      -5.6969886       2.2316978      0.62020731      0.45567566
... 
Format:
! Comment records (starting with '!')
L1C format identifier (real number)
NSweeps in this file
date# [days], time in Day [seconds], date (yyyymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#1
sweep#, alt, err on alt, lat, long, radcrv, NMic
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#1
p1, p2, ... spectral points in MW#1
MWlabel, npt, wno1, wno2, NESR for MW#2 in sweep#1
p1, p2, ... spectral points in MW#2
 etc ... 
date# [days], time in Day [seconds], date (yymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#2
sweep#, alt[km], err on alt[km], lat, long, radcrv[km], NMic
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#2
 etc ...

L1C format 1.1

Generated by LV2PP v.13AUG02 onwards. Changes from previous version highlighted in red

Example:

! L1C file generated by LV2PP v.13AUG02 on Tue Aug 13 12:18:35
! L1B FILE: MIP_NL__1P_20405_072642_0504_new_ANX_020513 
! L1C FORMAT: http://www.atm.ox.ac.uk/group/mipas/L1C/
1.1
17
  825  26807  20020405  072647    504     28.8572     64.0312
    1     68.1554      0.0000     67.4756     43.1906   6390.1534    6
O3__0001     121    1122.800    1125.800       13.1525
   -0.5549    0.5844   -6.2134   -5.6970    2.2317    0.6202    0.4557    4.1068
    6.3651   -0.8872    0.8628   12.7399   11.8993    6.6095    1.8502  -10.9848
  ...
Format:
! Comment records (starting with '!')
L1C format identifier (real number)
NSweeps in this file
date# [days], time in Day [seconds], date (yyyymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#1
sweep#, alt, err on alt, lat, long, radcrv, NMic
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#1
p1, p2, ... spectral points in MW#1
MWlabel, npt, wno1, wno2, NESR for MW#2 in sweep#1
p1, p2, ... spectral points in MW#2
 etc ... 
date# [days], time in Day [seconds], date (yymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#2
sweep#, alt[km], err on alt[km], lat, long, radcrv[km], NMic
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#2
 etc ...

L1C format 1.0

Generated by LV2PP v.04JUN02-23JUL02

Example:

! L1C file generated by LV2PP v.04JUN02 on Wed Jun  5 16:05:45
! SOURCE FILE:
! /home/crun/eodg/mipas/L1B/MIP_NL__1P_20405_072642_0504_new_ANX_020513
! L1C FORMAT: http://www.atm.ox.ac.uk/group/mipas/L1C/
1.0
17
  825  26807  020405  072647    504     28.8572     64.0312
    1     68.1554      0.0000     67.4756     43.1906   6390.1534    6
O3__0001     121    1122.800    1125.800       13.1525
   -0.5549    0.5844   -6.2134   -5.6970    2.2317    0.6202    0.4557    4.1068
    6.3651   -0.8872    0.8628   12.7399   11.8993    6.6095    1.8502  -10.9848
  ...
Format:
! Comment records (starting with '!')
L1C format identifier (real number)
NSweeps in this file
date# [days], time in Day [seconds], date (yymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#1
sweep#, alt, err on alt, lat, long, radcrv, NMic
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#1
p1, p2, ... spectral points in MW#1
MWlabel, npt, wno1, wno2, NESR for MW#2 in sweep#1
p1, p2, ... spectral points in MW#2
 etc ... 
date# [days], time in Day [seconds], date (yymmdd), time (hhmmss), orbit#, LST [hours], SZA [deg] for sweep#2
sweep#, alt[km], err on alt[km], lat, long, radcrv[km], NMic
MWlabel, npt, wno1, wno2, NESR for MW#1 in sweep#2
 etc ...

Last modified: 13-AUG-02 AD