mav-mag-pds.xml
8.02 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
<?xml version="1.0" encoding="UTF-8"?>
<Spase xmlns="http://www.spase-group.org/data/schema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.spase-group.org/data/schema http://cdpp.irap.omp.eu/AMDA-NG/public/schemas/spase-amda-1_2_0.xsd">
<Version>2.2.6</Version>
<NumericalData>
<ResourceID>spase://CDPP/NumericalData/AMDA/MAVEN/MAG/mav-mag-pds</ResourceID>
<ResourceHeader>
<ResourceName>0.03 sec</ResourceName>
<ReleaseDate>2015-10-12T10:48:29Z</ReleaseDate>
<Description> * Calibrated science vector magnetic-field data in Planetocentric coordinates (IAU Mars) vs. time (LID = urn:nasa:pds:maven.mag.calibrated:data.pc)
* Calibrated science vector magnetic-field in Sun-State (MSO) coordinates vs. time (LID = urn:nasa:pds:maven.mag.calibrated:data.ss)
</Description>
<Acknowledgement>Principal Investigator : John E.P. Connerney, NASA GODDARD, Greenbelt</Acknowledgement>
<Contact>
<PersonID>spase://SMWG/Person/John.E.P.Connerney</PersonID>
<Role>PrincipalInvestigator</Role>
</Contact>
<InformationURL>
<Name>MAG web page, Summary sheet </Name>
<URL>http://lasp.colorado.edu/home/maven/science/instrument-package/mag/</URL>
<Description/>
</InformationURL>
</ResourceHeader>
<AccessInformation>
<RepositoryID>spase://SMWG/Repository/CDPP/AMDA</RepositoryID>
<Availability>Online</Availability>
<AccessRights>Open</AccessRights>
<AccessURL>
<Name>AMDA at CDPP</Name>
<URL>
http://amda.cdpp.eu
</URL>
</AccessURL>
<Format>Text.ASCII</Format>
<Acknowledgement> AMDA is a science analysis system provided by the Centre de Donnees de la
Physique des Plasmas (CDPP) supported by CNRS, CNES, Observatoire de Paris and
Universite Paul Sabatier, Toulouse
</Acknowledgement>
</AccessInformation>
<ProviderName>PDS</ProviderName>
<ProviderResourceName>maven-mag-calibrated/pc[ss]</ProviderResourceName>
<ProviderAcknowlegment/>
<InstrumentID>spase://CDPP/Instrument/AMDA/MAVEN/MAG</InstrumentID>
<MeasurementType>MagneticField</MeasurementType>
<TemporalDescription>
<TimeSpan>
<StartDate>2014-10-10T00:00:00Z</StartDate>
<StopDate>2017-05-15T00:00:00Z</StopDate>
</TimeSpan>
<Cadence>PT0.031S</Cadence>
</TemporalDescription>
<ObservedRegion>Mars</ObservedRegion>
<Caveats>MAG data products are provided in several useful coordinate systems and at the highest time resolution
available. The MAG observations contain some known artifacts that you may encounter in your use of the
data that you should be aware of. These are related to several different sources on the spacecraft that have
been, and continue to be, under investigation. This message is dated April 10, 2015, and it represents
our current (and evolving) understanding of the status of the spacecraft and its influence on MAG
data. These include:
* rapid magnetic field variations of ~6 nT in magnitude (in spacecraft payload coordinate axes y and z) associated with infrequent thruster firings (every few days) that are employed in trajectory correction maneuvers (TCM). These are relatively easy to identify.
* variations (in spacecraft payload coordinate axes y and z) of ~1 nT in magnitude associated with solar array currents in circuits at the outer edge of the solar arrays, near the magnetometer sensor. MAG processing mitigates these signatures where spacecraft engineering telemetry is available at high time resolution. The necessary spacecraft engineering data was made available after Jan 9, 2015, following in-flight spacecraft testing to isolate the problem. Prior to this time, we use a coarse indication of solar array currents to correct the data, and this correction will be out of time step with the actual needed correction part of the time. Corrections applied are listed on each record along with the corrected data. These variations may appear as step functions, e.g., when the spacecraft enters eclipse, or slow variations as the spacecraft attitude with respect to the sun varies. They were identified in the quiet, weak field environment of cruise and when illumination on the solar arrays was more intense than experienced in cruise.
* multiple sinewave variations usually of ~0.1 nT in magnitude, that track the frequency of operation of the four Reaction Wheel Assemblies (RWAs). The magnitude of these variations has been observed to increase substantially when the RWAs are operated at very low frequencies; at such times they may appear prominently in spectra of MAG observations.
* the "static" or slowly-varying spacecraft field has been estimated using spacecraft roll maneuvers that are scheduled to occur approximately every 2 months. The MAVEN static sc field specification was NTE 2 nT. The MAG data processed for December 2014 use an estimate of the spacecraft field obtained from the day 353 2014 magroll maneuvers, the only set performed subsequent to deployment of the APP after insertion into Mars orbit. We have yet to verify if this sc field estimate remains relatively constant or if it varies over the interval between magroll maneuvers. Investigation of the time variability of this part of the sc field is expected shortly.
</Caveats>
<Parameter>
<Name>b_mso</Name>
<ParameterKey>mavb_mso</ParameterKey>
<Description/>
<Ucd>phys.magField</Ucd>
<Units>nT</Units>
<UnitsConversion/>
<Structure>
<Size>3</Size>
<Element>
<Name>bx</Name>
<!--Qualifier/-->
<Index>1</Index>
<ParameterKey>mavb_mso(0)</ParameterKey>
<ValidMin/>
<ValidMax/>
<FillValue/>
</Element>
<Element>
<Name>by</Name>
<!--Qualifier/-->
<Index>2</Index>
<ParameterKey>mavb_mso(1)</ParameterKey>
<ValidMin/>
<ValidMax/>
<FillValue/>
</Element>
<Element>
<Name>bz</Name>
<!--Qualifier/-->
<Index>3</Index>
<ParameterKey>mavb_mso(2)</ParameterKey>
<ValidMin/>
<ValidMax/>
<FillValue/>
</Element>
</Structure>
<Field>
<FieldQuantity>Magnetic</FieldQuantity>
</Field>
</Parameter>
<Parameter>
<Name>b_iau_mars</Name>
<ParameterKey>mavb_iau</ParameterKey>
<Description/>
<Ucd>phys.magField</Ucd>
<Units>nT</Units>
<UnitsConversion/>
<Structure>
<Size>3</Size>
<Element>
<Name>bx</Name>
<Qualifier>Component</Qualifier>
<Index>1</Index>
<ParameterKey>mavb_iau(0)</ParameterKey>
<ValidMin/>
<ValidMax/>
<FillValue/>
</Element>
<Element>
<Name>by</Name>
<Qualifier>Component</Qualifier>
<Index>2</Index>
<ParameterKey>mavb_iau(1)</ParameterKey>
<ValidMin/>
<ValidMax/>
<FillValue/>
</Element>
<Element>
<Name>bz</Name>
<Qualifier>Component</Qualifier>
<Index>3</Index>
<ParameterKey>mavb_iau(2)</ParameterKey>
<ValidMin/>
<ValidMax/>
<FillValue/>
</Element>
</Structure>
<Field>
<FieldQuantity>Magnetic</FieldQuantity>
</Field>
</Parameter>
<Parameter>
<Name>|b|</Name>
<ParameterKey>mavb_tot</ParameterKey>
<Description/>
<Ucd>phys.magField</Ucd>
<Units>nT</Units>
<UnitsConversion/>
<ValidMin/>
<ValidMax/>
<FillValue/>
<Field>
<FieldQuantity>Magnetic</FieldQuantity>
</Field>
</Parameter>
</NumericalData>
</Spase>