Introduction to Lightning Imaging Sensor (LIS)

ORBIT
structure name: orbit
  Status Parameter Structure Element Name Type Size Description
A   Orbit ID id_number int32 1 the number of this orbit, where the orbit count starts at launch
B   TAI93 start time TAI93_start float64 1 start of this orbit in TAI93 time (leading edge of field-of-view crossing longitude orbit boundary)
C   UTC start time UTC_start char 28 start of this orbit in UTC time
D   GPS start time GPS_start float64 1 start of this orbit in GPS time
E   TAI93 end time TAI93_end float64 1 end of this orbit in TAI93 time (trailing edge of field-of-view crossing orbit boundary)
F   start longitude start_longitude float32 1 longitude boundary defining start of this orbit
G   end longitude end_longitude float32 1 longitude boundary defining end of this orbit
H   number of point data records point_data_count int16 1 number of point data elements associated with this orbit
I   point data child record number point_data_address int16 1 address of the first element in point data structure that corresponds with this orbit
J   number of one-second records one_second_count int32 1 number of elements in the one-second data associated with this orbit
K   one-second child record number one_second_address int32 1 address of the first element in the one-second data structure that corresponds with this orbit
L   number of summary GIF images summary_image_count int16 1 number of summary GIF images associated with this orbit
M   summary GIF image record number summary_image_address int16 1 address of the first summary GIF image structure that corresponds with this orbit
N   Inspection Code inspection_code int16 1 Code indicating which problem scenarios were checked by the QA inspector
O   Configuration Code config_code int16 1 Code indicating which code configuration scenario was used when processing the data

Notes:

Field N: This field is used to identify which QA procedure was followed at the time of the QA inspection. It is expected that the QA procedure will evolve as more data is collected and new "problems" are identified. As a result, each orbit must be marked so that the user (and QA inspector) can identify which orbits were checked for specific "problems".

Field O: This field is used to identify when a change is made to the code that processed the data, such as changes in the input parameters to the processing code. Each orbit must be marked so that the user (and QA inpector) can identify which orbits were processed using specific input parameters.

Fields F & G: The start longitude is defined as the satellite nadir longitude (rounded to the nearest 0.5 degrees) at the time when the satellite is at its southernmost point in the orbit. The end longitude is calculated in the same manner, and it is the same longitude as the start longitude for the following orbit.

Fields B & E: The start time corresponds with the time which the leading edge of the instrument field-of-view crosses the start longitude, which is BEFORE the time of the satellite nadir crossing of this longitude. Similarly, the end time corresponds with the time that the trailing edge of the instrument field-of-view crosses the end longitude, which is AFTER the time of the satellite nadir crossing of this longitude. Note that there will be some overlap in the time spans of successive orbits.