Skip to end of metadata
  • Created by Former user, last modified by Former user on Sept 15, 2020
Go to start of metadata

You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 20 Next »

SEGY is a data format developed by the Society of Exploration Geophysicists (SEG) for storing geophysical data. DAOS-SEGY aims at implementing the SEGY data format natively on top of the DAOS storage model in order to accelerate data access and to provide in-storage computing capabilities to process data in place.


The project is still in its early days and the following mapping is under consideration:

Object SEISROOT
# Root object storing global metadata and references to 2nd level objects (shot, offset, cmp, ...)
D-key "Gather keys"
    A-key "nkeys" number of keys that will be used to create gather objects.
    A-key "key_1" first key name that will be used to create a gather object.
...
    A-key "key_n" nth key name that will be used to create a gather object.
D-key "File Headers"
    A-key "ntraces" total number of traces under seismic root object.
    A-key "Binary File Header", binary file header.
    A-key "Text File Header", textual file header.
    A-key "n_EXTH", number of extended textual file headers.
    A-key "EXTH_1", 1st extended textual file header.
    ...
    A-key "EXTH_n", nth extended textual file header.
D-key "Sorting Types"
    A-key "Key_name_1", objid of first-gather object
...
    A-key "Key_name_n", objid of nth-gather object
-------------------------------------------------------------------------------------------------------------------------
Object Gather_1 (Shot_gather object for example)
# Object storing all gathers under the first key_name
D-key "ngathers", total number of gathers saved under this gather object
D-key "Val(1)", first gather
    A-key "Trace_hdr_oids", objid of the array object holding oids of all traces_headers objects belonging to this gather.
    A-key "Unique_val", gather unique value(shot_id if it's shot object).
    A-key "ntraces", total number of traces belonging to this gather object.
...
D-key "Val(n)", nth gather
    A-key "Trace_hdr_oids", objid of the array object holding oids of all traces_headers objects belonging to this gather.
    A-key "Unique_val", gather unique value(shot_id if it's shot object).
    A-key "ntraces", total number of traces belonging to this gather object.
-------------------------------------------------------------------------------------------------------------------------
Object Gather_n (cmp_gather object for example)
# Object storing all gathers under the first key_name
D-key "ngathers", total number of gathers saved under this gather object
D-key "Val(1)", first gather
    A-key "Trace_hdr_oids", objid of the array object holding oids of all traces_headers objects belonging to this gather.
    A-key "Unique_val", gather unique value(cmp_value if it's cmp object).
    A-key "ntraces", total number of traces belonging to this gather object.
...
D-key "Val(n)", nth gather
    A-key "Trace_hdr_oids", objid of the array object holding oids of all traces_headers objects belonging to this gather. 
    A-key "Unique_val", gather unique value(cmp_value if it's cmp object).
    A-key "ntraces", total number of traces belonging to this gather object.
-----------------------------------------------------------------------------------------------------------------------------
Object Trace_Hdr_oids
#array object storing all traces header object ids belonging to one gather under specific gather object.  
D-key "0"
    A-key "oids[0:499]", array of traces_headers object ids from trace header 0 to trace header 499.
...
D-Key "n"
    A-key "oids[ntraces-500:ntraces]", array of traces_headers object ids from trace header (ntraces-500) to the last trace.
-----------------------------------------------------------------------------------------------------------------------------
Object Trace_Header
#object storing all trace headers.
#each trace is splitted into two objects, header object to hold trace header and data object to hold trace data.
D-key "hdr", trace metadata
    A-key "hdr", array storing all trace headers(240 byte).
-----------------------------------------------------------------------------------------------------------------------------
Object Trace_Data
#array object storing trace data.
D-key "0"
    A-key "data[0:199]", array storing data of first 200 sample in the trace.
...
D-key "data[tmax-200:tmax]"
    A-key "data", array storing data of last 200 sample in the trace.


  • No labels