MORSE Common File Format

04SEP25

Common File Structure
File_Header
For iPix = 1, nPix
Pixel_Header
For iSet = 1, nSet
Set_Header
Profile_Data

A 'set' is an optional subdivision of outputs at various stages of the retrieval. Normally there is just one set corresponding to the final product but MORSE can also output the a priori profiles (APR flag) — always the first set — and retrieval products after each microwindow (MWO flag), culminating in the final product.

File Header

Structure

File Header
! FILTYP generated by MORSE v.VERSID
! HDRREC			Header record set in driver file
FMT			File format version
IGEOM			Viewing geometry (eg 1=limb-viewing)
INST_ID	SAT_ID		Instrument, Satellite
YYYYMMDD	JDAY		Nominal date, Day# since 1Jan2000
ORBIT	ORBSTA	ORBEND	Orbit#, Start HHMMSS, End HHMMSS
NPIX	NSET		No. pixels or limb scans, No. sets/scan
NLEV	NPRF		(Max) No. Levels/Profile, No. Profiles/Set
*GRD			Vertical grid coordinate
GRD(1) GRD(2) ...			Vertical grid levels
... GRD(NLEV)
For j=1, NPRF			List of types of data profile
PRF(j)	NLVPRF(j)		Profile type, No. levels in profile
If NLVPRF(j) ≠ NLEV the following record is added
LEV_FLG(1,j) LEV_FLG(2,j) ... LEV_FLG(NLEV,j)
*END			End of Header marker record

Fields

Field	Format	Description	Units	Range
FILTYP	C*	Type of file, eg Retrieval State Vector
VERSID	C11	MORSE version identifier eg 27APR23
HDRREC	C79	Copied from *HDR section of the driver table
FMT	F10.2	MORSE output file format identifier		2.00
IGEOM	I10	Viewing geometry		1, 2 or 3
INST_ID	C10	Instrument identification eg IASI-A
SAT_ID	C10	Satellite identification eg MetOp-A
YYYYMMDD	I10	Year, Month, Day of data	yyyymmdd
JDAY	I10	Day# since 1 Jan 2000 (JDAY=0)		≥ 0
ORBIT	I10	Orbit number since launch		≥ 0
ORBSTA	I10	Orbit start time	hhmmss
ORBEND	I10	Orbit end time	hhmmss
NPIX	I10	No. of pixels or profile locations		≥1
NSET	I10	No. sets of retrievals per pixel [1]		≥1
NLEV	I10	Max. No. levels in each profile		≥1
NPRF	I10	No. different profiles (or scalars) listed per pixel		≥1
*GRD	C	Profile grid [2]		∈ {*PRE, *HGT, *HGT_NOM }
GRD(NLEV)	*	Profile grid values, lowest alt to highest	km or hPa
PRF(NPRF)	C7	Profile type #j [3]
NLVPRF(NPRF)	I5	No. levels on which profile#j is represented[4]		≥0
LEV_FLG(NLEV,NPRF)	I2	1 if Profile#j is retrieved on Level#i, else 0 [5]		∈ { 0, 1 }

Notes

1. NSET is normally 1, but increased by 1 if the APR flag is set, and/or increased by the number of microwindows/bands −1 if the MWO flag is set

   APR	MWO	NSET
   F	F	1
   T	F	2
   F	T	NMIC
   T	T	NMIC+1

2. *GRD is determined by the grid set in the section#4 of the morse.drv file

   Driver File	*GRD in output File	Grid type
   *PRE	*PRE [hPa]	Pressure levels
   *ALT	*HGT [km]	Altitude levels
   *TAN	*HGT_NOM [km]	Nominal tangent point altitudes

3. PRF: Apart from the retrieved species this includes diagnostic and supplementary information, including scalar quantities. See descriptions of individual file types for possible values.

4. NLVPRF: A value 0 is used for column or scalar retrievals, to distinguish these from profiles where a single retrieval level is specified with upper and/or lower bounds.

5. LEV_FLG: It is possible to specify individual retrievals on subsets of the full grid, in which case NLVPRF(j) < NLEV, and then the PRF record in the header section is immediately followed by a records containing NLEV LEV_FLG values to indicate the particular retrieval levels (1=used, 0=skipped).

Structure

3 records, different for limb and nadir-viewing geometries.

Pixel Header (Nadir-Viewing)
IPIX       = Pixel#	Pixel counter
!YYYYMMDD HHMMSS MILLISEC STP FOV LAT LON ZEN SZA %CLD %LND	Header record
YMD           HMS           MSC      STP  FOV  LAT  LON  ZEN  SZA    CLD    LND	Data record

Pixel Header (Limb-Viewing)
IPIX       = Pixel#	Profile location counter
!YYYYMMDD HHMMSS MILLISEC LAT LON LST SZA	Header record
YMD           HMS           MSC      LAT  LON  LST  SZA	Data record

Fields

Field	Format	Description	Units	Range
IPIX	I10	Pixel/location number		1 : NPIX
YMD	I9.8	Date of the scan eg ' 20020724'	yyyymmdd
HMS	I7.6	Time (UT) of the scan[1] eg ' 113640'	hhmmss	000000 : 235959
MSC	I9	Milliseconds into day[1]	ms	0 : 86 400 000
STP	I4	(Nadir) IASI Mirror step#		1 : 30
FOV	I4	(Nadir) IASI Pixel/FOV#		1 : 4
LAT	F7.2	Latitude	deg N	±90
LON	F8.2	Longitude	deg E	±180
ZEN	F7.2	(Nadir) Satellite Zenith Angle (0=overhead)	deg	0 – 90
LST	F7.4	(Limb) Local Solar Time (12=noon)	hr	0 – 24
SZA	F7.2	Solar Zenith Angle (>0 ≡ daytime)	deg	±90
CLD	F7.1	(Nadir) Cloud fraction in FOV	%	0 – 100
LND	F7.1	(Nadir) Land fraction in FOV	%	0 – 100

Notes

1. While all the information in HMS is also contained in MSC, it is a more 'human' readable representation of time of day.

2. The time and location information for a limb scan of multiple sweeps is based on that of the central sweep in the scan

Structure

A single record which can be read as a comment record but, in the case of multiple sets created by the MWO Flag (i.e., output after each microwindow is processed), the Set Header is a Microwindow Header containing formatted microwindow details.

Fields

Field	Type	Description	Range
SET_HEADER	C*	Retrieval step of data within set:
		if iSet=NSET:	'! Final Result'
		if APR Flag and iSet=1:	'! A Priori'
		if MWO Flag and iSet<NSET:	Microwindow_Header

Microwindow Header
! IMIC   MICLAB   WNOMIN   WNOMAX   [ALTMIN   ALTMAX]
Field	Type	Description	Units	Range
IMIC	I2	Microwindow# in list		> 0
MICLAB	A8	Microwindow label, e.g. 'MIC_001 '
WNOMIN	F10.4	Lower wavenumber limit	cm-1	0 < : < WNOMAX
WNOMAX	F10.4	Upper wavenumber limit	cm-1	> WNOMIN
Optional (both or neither)
ALTMIN	F5.1	Lower tangent height limit	km	< ALTMAX
ALTMAX	F5.1	Upper tangent height limit	km	> ALTMIN

Notes

1. The microwindow header record is composed in subroutine addmic_sub.f90

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