PURPOSE

The purpose of this appendix is to define the content and format of the SABER Level 1B file. This file will be a product produced by the SABER Level 1B processing software. It will contain calibrated radiance profiles for each SABER channel and all information required to retrieve constituents in Level 2 processing. The Level 1B file will be in the NetCDF format.

BACKGROUND

The Level 1B file will be the output from Level 1B processing, which reads in a Level 1A file, removes instrument and spacecraft effects, co-aligns channels, converts to radiance units, geolocates each sample and grids to uniform angle spacing.

REQUIREMENTS

The Level 1B file will contain radiance profiles as a function of angle, height, latitude, longitude and time. Other derived requirements include:

• Event number for current day
• Spacecraft latitude, longitude and altitude
• Day/Night flag for tangent point
• Orbit Ascending/Descending flag
• Solar Zenith Angle at Tangent point
• NMC profile (P,Z,T) near the 60 km tangent point location
• Solar Ap, Kp, F10.7 and sunspot number

FORMAT

Following the Common Data form Language (CDL) definition of a NetCDF file, the Level 1B will contain:

• Dimensions

event = 2200; // Scan event number for current day (~2200)

elevation = 800; // Elevation angle relative to horizon

                                // (22.7 Hz x 33 sec rounded up)

             pressure_nmc = 64; // NMC pressure levels

• Variables

short event(event) // Event number for current day

long date(event) // Date [YYYYDDD]

double elevation(elevation) // Elevation Angle (SABER centric)[milliradians]

long time(event, elevation) // Msec since midnight

char mode(event) // 0=Down 1=Up

float sclatitude(event, elevation) // Spacecraft latitude (degrees)

float sclongitude(event, elevation) // Spacecraft longitude (degrees)

float scaltitude(event, elevation) // Spacecraft altitude (km)

float latitude(event, elevation) // Tangent point latitude

float longitude(event, elevation) // Tangent Point longitude

char tpDN(event) // 0=Day 1=Night

char scAD(event) // 0=Ascending 1=Descinding

float tpSolarZen(event) // Tangent point solar zenith angle (degrees)

float tpSolarLT(event) // Tangent point local solar time (msec since midnight UT)

float channel_1(event, elevation) // Channel 1 radiance (watts/cm2/sr)

float channel_2(event, elevation) // Channel 2 radiance (watts/cm2/sr)

float channel_3(event, elevation) // Channel 3 radiance (watts/cm2/sr)

float channel_4(event, elevation) // Channel 4 radiance (watts/cm2/sr)

float channel_5(event, elevation) // Channel 5 radiance (watts/cm2/sr)

float channel_6(event, elevation) // Channel 6 radiance (watts/cm2/sr)

float channel_7(event, elevation) // Channel 7 radiance (watts/cm2/sr)

float channel_8(event, elevation) // Channel 8 radiance (watts/cm2/sr)

float channel_9(event, elevation) // Channel 9 radiance (watts/cm2/sr)

float channel_10(event, elevation) // Channel 10 radiance (watts/cm2/sr)

float pressure_nmc(event, pressure_nmc) // NMC pressure at TP (mbar)

float temperature_nmc(event, pressure_nmc) // NMC temperature at TP (K)

float altitude_nmc(event, pressure_nmc) // NMC altitude at TP (km)

short solKP(event) // Solar Kp index

short solAP(event) // Solar Ap index

float solf10p7Daily(event) // F10.7 flux (daily)

float solF10p781dAvg(event) // F10.7 flux (81-day average)

short solSpotNo(event) // Zurich Sunspot Number

• Data

Event (1-2500)

Elevation (TBD)

• Attributes

ESTIMATED FILE SIZE

Total Estimated file size (Mbytes): 0.068200 + 105.6 + 2.2528 = 108 Mbytes