The compression rate of on board EIS data may vary depending on a few factors such as the observing target (QS, AR, CH, etc), slit/slot selection, exposures, etc.
The purpose of this study is trying to investigate how different compression schemes effect EIS data volume on board and work out a better estimation of compression rate for compression scheme (eg. DPCM, JPEG98, JPEG95, etc.)
The approach:
1. to get actual data volume from MDP status information: the inclined curve means data packets from EIS on MDP, the vertical curve means data packets dumped to ground station. So in general, known a raster's start and end time can calculate actual data volume, and then compare it with the designed data volume of this raster to get data compression rate.
[{Image src='images/factor/dataVolume_eis.png}]
2. to get related information from planning database/eis catalogue/fits header, for example: raster ID, compression scheme, designed data volume, SCI_OBJ, TARGET, slit/slot, exposures, etc.
3. prepare plots based on various factor combinations: compression rate vs. slit/slot, rate vs. target, rate vs. exposures
----
Some preliminary results (plots):\\
(The investigation here is for dates between %%(color:#cc0000;)2007-Sep-15 and 2007-Dec-15%%, as EIS is operationally stable over this duration.)
%%tabbedSection
%%tab-DPCM
%%(text-align:center)
!DPCM compression (all samples)
%%
[{Image src='images/factor/dpcm/DPCM_only.gif}]
%%(text-align:center)
!DPCM compression vs different target
%%
DPCM vs. QS
[{Image src='images/factor/dpcm/DPCM_QS_only.gif}]
DPCM vs. AR
[{Image src='images/factor/dpcm/DPCM_AR_only.gif}]
DPCM vs. CH
[{Image src='images/factor/dpcm/DPCM_CH_only.gif}]
DPCM vs. PCH
[{Image src='images/factor/dpcm/DPCM_PCH_only.gif}]
DPCM vs. FIL
[{Image src='images/factor/dpcm/DPCM_FIL_only.gif}]
%%(text-align:center)
!DPCM compression vs SLA selection
%%
DPCM vs. 1" slit
[{Image src='images/factor/dpcm/DPCM_1arcsec_only.gif}]
DPCM vs. 2" slit
[{Image src='images/factor/dpcm/DPCM_2arcsec_only.gif}]
DPCM vs. 40" slit
[{Image src='images/factor/dpcm/DPCM_1arcsec_only.gif}]
DPCM vs. 266" slit
[{Image src='images/factor/dpcm/DPCM_266arcsec_only.gif}]
%%(text-align:center)
!DPCM compression vs different exposures
%%
DPCM vs. 10 second
[{Image src='images/factor/dpcm/DPCM_10s_only.gif}]
DPCM vs. 15 second
[{Image src='images/factor/dpcm/DPCM_15s_only.gif}]
DPCM vs. 20 second
[{Image src='images/factor/dpcm/DPCM_20s_only.gif}]
DPCM vs. 30 second
[{Image src='images/factor/dpcm/DPCM_30s_only.gif}]
DPCM vs. 60s second
[{Image src='images/factor/dpcm/DPCM_60s_only.gif}]
%%(text-align:center)
!DPCM compression vs 1" SLA selection vs exposures
%%
DPCM vs. 1" slit vs. 10s exposures
[{Image src='images/factor/dpcm/DPCM_1arcsec_10s_only.gif}]
DPCM vs. 1" slit vs. 15s exposures
[{Image src='images/factor/dpcm/DPCM_1arcsec_15s_only.gif}]
DPCM vs. 1" slit vs. 20s exposures
[{Image src='images/factor/dpcm/DPCM_1arcsec_20s_only.gif}]
DPCM vs. 1" slit vs. 30s exposures
[{Image src='images/factor/dpcm/DPCM_1arcsec_30s_only.gif}]
DPCM vs. 1" slit vs. 60s exposures
[{Image src='images/factor/dpcm/DPCM_1arcsec_60s_only.gif}]
%%(text-align:center)
!DPCM compression vs 2" SLA selection vs exposures
%%
DPCM vs. 2" slit vs. 10s exposures
[{Image src='images/factor/dpcm/DPCM_2arcsec_10s_only.gif}]
DPCM vs. 2" slit vs. 15s exposures
[{Image src='images/factor/dpcm/DPCM_2arcsec_15s_only.gif}]
DPCM vs. 2" slit vs. 20s exposures
[{Image src='images/factor/dpcm/DPCM_2arcsec_20s_only.gif}]
DPCM vs. 2" slit vs. 30s exposures
[{Image src='images/factor/dpcm/DPCM_2arcsec_30s_only.gif}]
DPCM vs. 2" slit vs. 60s exposures
[{Image src='images/factor/dpcm/DPCM_2arcsec_60s_only.gif}]
%%(text-align:center)
!DPCM compression vs 40" SLA selection vs exposures
%%
DPCM vs. 40" slit vs. 10s exposures
[{Image src='images/factor/dpcm/DPCM_40arcsec_10s_only.gif}]
DPCM vs. 40" slit vs. 15s exposures
[{Image src='images/factor/dpcm/DPCM_40arcsec_15s_only.gif}]
DPCM vs. 40" slit vs. 20s exposures
[{Image src='images/factor/dpcm/DPCM_40arcsec_20s_only.gif}]
DPCM vs. 40" slit vs. 30s exposures
[{Image src='images/factor/dpcm/DPCM_40arcsec_30s_only.gif}]
DPCM vs. 40" slit vs. 60s exposures
[{Image src='images/factor/dpcm/DPCM_40arcsec_60s_only.gif}]
%%(text-align:center)
!DPCM compression vs 266" SLA selection vs exposures
%%
DPCM vs. 266" slit vs. 10s exposures
[{Image src='images/factor/dpcm/DPCM_266arcsec_10s_only.gif}]
DPCM vs. 266" slit vs. 15s exposures
[{Image src='images/factor/dpcm/DPCM_266arcsec_15s_only.gif}]
DPCM vs. 266" slit vs. 20s exposures
[{Image src='images/factor/dpcm/DPCM_266arcsec_20s_only.gif}]
DPCM vs. 266" slit vs. 30s exposures
[{Image src='images/factor/dpcm/DPCM_266arcsec_30s_only.gif}]
DPCM vs. 266" slit vs. 60s exposures
[{Image src='images/factor/dpcm/DPCM_266arcsec_60s_only.gif}]
%%
%%tab-SecondTab
This is the second tab
%%
%%tab-ThirdTab
This is the third tab
%%
%%
[{Image src='images/factor/75/JPEG75_only.gif'}]
QS QS,DC QS,SYN QS,CH QS,NET QS,DC,XBP QS,SYN,DC QS,DC,SEI QS,PCH
XBP,QS
AR AR,LMB AR,EFR AR,PLG AR,CH AR,NFL AR,CH,LMB
SYN SYN,DC SYN,QS,DC
PCH PCH,LMB,JET PCH,JET
JET,LMB,PCH
LMB LMB,LO LMB,PCH,SPI LMB,SPI
ENG,LMB,JET,PCH ENG,QS,DC
SYN,DC,QS SYN,DC
CH CH,JET CH,XBP CH,DC CH,LMB CH,QS CH,XBP,JET,EFR CH,BP,JET
PR PR,LMB PP,PCH
SPI,LMB
EFR SEI,EFR
DC DC,LMB WAV NET
SPI SPI,CH
BP,CH,JET BP,JET
FIL,PR FIL,QS