urn:nasa:pds:radiosci.documentation:dsn.0159-science:i070135a
1.1
Mars Express Example Downlink Predicted Frequency (DLF)
1.16.0.0
Product_Observational
Simpson, R. A.
2018
Mars Express Downlink Predicted X-band Frequencies
2021-09-29
1.1
Updated to IM v1.16.0.0
2020-02-24
1.0
Initial version
2018-03-11T13:52:58Z
2018-03-12T03:10:15Z
Calibration
Calibrated
Mars Express downlink predicted frequencies
Mars Express
Mission
urn:nasa:pds:context:investigation:mission.mars_express
data_to_investigation
Mars Express
Host
urn:nasa:pds:context:instrument_host:spacecraft.mex
is_instrument_host
Mars Express Radio Science
Instrument
M. Pätzold, S. Tellmann, T. Andert, L. Carone, M. Fels, R. Schaa, C. Stanzel,
I. Audenrieth-Kersten, A. Gahr, A.-L. Müller, B. Stracke, D. Stupar, C. Walter,
B. Häusler, S. Remus, J. Selle, H. Griebel, W. Eidel, S. Asmar, G. Goltz, D. Kahan,
J.-P. Barriot, V. Dehant, M. Beuthe, P. Rosenblatt, Ö. Karatekin, V. Lainey,
G.L. Tyler, D. Hinson, R. Simpson, and J. Twicken.
MaRS: Mars Express Radio Science Experiment, pages 217-245,
in Mars Express: The Scientific Investigations,
European Space Agency SP-1291, June 2009.
https://sci.esa.int/documents/33745/35957/1567258041276-MaRS.pdf
The Mars Express Radio Science Experiment (MaRS) started regular operations in April 2004.
The experiment employed radio occultation during two occultation seasons in April-August 2004
and December 2004 to sound the neutral martian atmosphere to derive vertical density, pressure
and temperature profiles as functions of height, and to sound the ionosphere to derive vertical
ionospheric electron density profiles. Both profile types were monitored as functions of time
in order to determine diurnal variations and, in the case of the ionosphere, dependence on
solar wind conditions. MaRS also determined the dielectric and scattering properties of the
martian surface in specific target areas by using bistatic radar, determining gravity anomalies
during pericentre passes at altitudes of 250 km for investigations of the structure and
evolution of the crust and lithosphere, and sounding the solar corona during the superior
conjunction of Mars with the Sun from mid-August to mid-October 2004. This document provides
an overview of the observations and analysis techniques using data from April 2004 to mid-2005.
(Adapted from the paper's abstract).
Mars
Planet
urn:nasa:pds:context:target:planet.mars
data_to_target
i070135a.dlf
2018-03-06T15:02:25
180564
fdd262b3157507bd8a48d005a0d0babb
File Header
0
1640
7-Bit ASCII Text
File header with production identification including spacecraft ID, DSN
receiving antenna number, start time, stop time, file creation time,
uplink band, and downlink band.
1-WAY Table Header
1640
328
7-Bit ASCII Text
Header for 1-WAY Predict Table. Information includes tracking mode, start
date and time, end date and time, and column headers for the data which
follow.
MAVEN ROSE 1-WAY Frequency Prediction Coefficients
1968
1073
Everett polynomial coefficients for 1-WAY frequency prediction.
To calculate predicted frequency (Fp) at time t use the following equations:
Fp(t) = (1-p)*f0 + g2*(1-p)*d20 + g4(1-p)*d40 + p*f1 + g2(p)*d21 + g4(p)*d41
where
f0 and f1 are frequencies at consecutive times t0 and t1 in the table
p = (t-t0)/(t1-t0)
g2(x) = x*(x*x-1)/6
g4(x) = x*(x*x-1)*(x*x-4)/120
Carriage-Return Line-Feed
6
0
82
Time
1
1
ASCII_Time
12
UTC time at the DSN receiving station in hh:mm:ss.sss format
Frequency
2
13
ASCII_Real
18
%18.4f
Hz
Predicted downlink frequency at Time
d20
3
31
ASCII_Real
13
%13.3f
Everett polynomial coefficient d20
d21
4
44
ASCII_Real
13
%13.3f
Everett polynomial coefficient d21
d40
5
57
ASCII_Real
12
%12.2f
Everett polynomial coefficient d40
d41
6
69
ASCII_Real
12
%12.2f
Everett polynomial coefficient d41
2-WAY Table Header
90036
328
7-Bit ASCII Text
Header for 2-WAY Predict Table. Information includes tracking mode, start
date and time, end date and time, and column headers for the data which
follow.
MAVEN ROSE 2-WAY Frequency Prediction Coefficients
90364
1097
Everett polynomial coefficients for 2-WAY frequency prediction.
To calculate predicted frequency (Fp) at time t use the following equations:
Fp(t) = (1-p)*f0 + g2*(1-p)*d20 + g4(1-p)*d40 + p*f1 + g2(p)*d21 + g4(p)*d41
where
f0 and f1 are frequencies at consecutive times t0 and t1 in the table
p = (t-t0)/(t1-t0)
g2(x) = x*(x*x-1)/6
g4(x) = x*(x*x-1)*(x*x-4)/120
Carriage-Return Line-Feed
6
0
82
Time
1
1
ASCII_Time
12
UTC time at the DSN receiving station in hh:mm:ss.sss format
Frequency
2
13
ASCII_Real
18
%18.4f
Hz
Predicted downlink frequency at Time
d20
3
31
ASCII_Real
13
%13.3f
Everett polynomial coefficient d20
d21
4
44
ASCII_Real
13
%13.3f
Everett polynomial coefficient d21
d40
5
57
ASCII_Real
12
%12.2f
Everett polynomial coefficient d40
d41
6
69
ASCII_Real
12
%12.2f
Everett polynomial coefficient d41