810-005, Rev. E
DSMS Telecommunications Link
Design Handbook

301
Coverage and Geometry
Effective November 30, 2000

Document Owner:              Approved by:

-----------------------      -----------------------
R.W. Sniffin       Date      A. Kwok          Date
                             Uplink Tracking and Command Service
                             Systems Development Engineer

Released by:
[Signature on file in TMOD Library]
------------------------
DSMS Document Release Date

Change Log
Rev           Issue Date               Affected Paragraphs       Change Summary
Initial       1/15/2001                All                       All


Note to Readers 
There are two sets of document histories in the 810-005 document, and these
histories are reflected in the header at the top of the page. First, the entire document is
periodically released as a revision when major changes affect a majority of the modules. For
example, this module is part of 810-005, Revision E. Second, the individual modules also
change, starting as an initial issue that has no revision letter. When a module is changed, a
change letter is appended to the module number on the second line of the header and a summary
of the changes is entered in the module's change log.
This module is essentially the same as 810-005, Rev. D, module GEO-10,
Rev. E. Information relating to decommissioned antennas has been removed, coverage charts
have been revised to reflect new capabilities, and a significant uplink coverage restriction at the
DSS 54 station is documented.

Contents
Paragraph                                                                                             Page
1 Introduction ......................................................................................... 6
1.1 Purpose............................................................................................. 6
1.2 Scope .............................................................................................. 6
2 General Information .................................................................................. 6
2.1 Station Locations................................................................................... 6
2.1.1 Antenna Reference Point .......................................................................... 6
2.1.2 IERS Terrestrial Reference Frame.................................................................. 8
2.1.2.1 ITRF Coordinates ............................................................................... 9
2.1.2.2 ITRF Site Velocities ........................................................................... 9
2.1.3 Geocentric Coordinates............................................................................ 9
2.1.4 Geodetic Coordinates.............................................................................. 9
2.2 Coverage and Mutual Visibility..................................................................... 15
2.2.1 Use of Transmitters Below Designated Elevation Limits ........................................... 15
2.2.1.1 Spacecraft Emergencies......................................................................... 15
2.2.1.2 Critical Mission Support....................................................................... 15
2.2.2 Mechanical Limits on Surveillance Visibility .................................................... 15
2.2.2.1 Azimuth-Elevation Antennas..................................................................... 16
2.2.2.2 X-Y Antennas .................................................................................. 16
2.2.2.3 Tilt-Azimuth-Elevation Antennas ............................................................... 16
2.2.3 Coverage Charts.................................................................................. 16
2.2.3.1 70-m Subnet Receive Coverage of Planetary Spacecraft .......................................... 16
2.2.3.2 70-m Subnet Transmit Coverage of Planetary Spacecraft.......................................... 17
2.2.3.3 34-m HEF Subnet Receive Coverage of Planetary Spacecraft ...................................... 17
2.2.3.4 34-m HEF Subnet Transmit Coverage of Planetary Spacecraft ..................................... 17
2.2.3.5 34-m BWG Antennas Receive Coverage of Planetary Spacecraft .................................... 18
2.2.3.6 34-m BWG Antennas Transmit Coverage of Planetary Spacecraft ................................... 18
2.2.3.7 26-m Subnet Receive Coverage of Earth Orbiter Spacecraft ...................................... 18
2.2.3.8 26-m Subnet Transmit Coverage of Earth Orbiter Spacecraft ..................................... 18
2.2.3.9 34-m BWG Antennas Receive Coverage of Earth Orbiter Spacecraft ................................ 18
2.2.3.10 34-m BWG Antennas Receive Coverage of Earth Orbiter Spacecraft ............................... 18
2.2.3.11 11-m Subnet Receive Coverage.................................................................. 19
2.2.4 Horizon Masks and Antenna Limits ................................................................ 19
3 Proposed Capabilities................................................................................ 19
3.1 70-m X-band Uplink Implementation ................................................................. 19
3.2 34-m BWG Ka-band Implementation ................................................................... 19
Appendix A References ................................................................................. 49

Illustrations
Figure                                                                                                Page
1. ITRF Cartesian and Geocentric Coordinate System Relationships ...................................... 10
2. DSN 70-m Subnet Receive Coverage, Planetary Spacecraft ............................................. 19
3. DSN 70-m Subnet Transmit Coverage, Planetary Spacecraft............................................. 20
4. DSN 34-m HEF Subnet Receive Coverage, Planetary Spacecraft.......................................... 21
5. DSN 34-m HEF Subnet Transmit Coverage, Planetary Spacecraft ........................................ 22
6. DSN 34-m BWG Antennas Receive Coverage, Planetary Spacecraft........................................ 23
7. DSN 34-m BWG Antennas Transmit Coverage, Planetary Spacecraft ...................................... 24
8. DSN 26-m Subnet Receive Coverage, Earth Orbiter Spacecraft ......................................... 25
9. DSN 26-m Subnet Transmit Coverage, Earth Orbiter Spacecraft ........................................ 26
10. DSN 34-m BWG Antennas Receive Coverage, Earth Orbiter Spacecraft................................... 27
11. DSN 34-m BWG Antennas Transmit Coverage, Earth Orbiter Spacecraft ................................. 28
12. DSN 11-m Subnet Earth Orbiter and Planetary Receive Coverage ...................................... 29
13. DSS 14 Hour-Angle and Declination Profiles and Horizon Mask........................................ 30
14. DSS 15 Hour-Angle and Declination Profiles and Horizon Mask........................................ 31
15. DSS 16 X-Y Profiles and Horizon Mask .............................................................. 32
16. DSS 23 Hour-Angle and Declination Profiles and Horizon Mask........................................ 33
17. DSS 24 Hour-Angle and Declination Profiles and Horizon Mask........................................ 34
18. DSS 25 Hour-Angle and Declination Profiles and Horizon Mask........................................ 35
19. DSS 26 Hour-Angle and Declination Profiles and Horizon Mask........................................ 36

Figure                                                                                                Page
20. DSS 27 Hour-Angle and Declination Profiles and Horizon Mask........................................ 37
21. DSS 33 Hour-Angle and Declination Profiles and Horizon Mask........................................ 38
22. DSS 34 Hour-Angle and Declination Profiles and Horizon Mask........................................ 39
23. DSS 43 Hour-Angle and Declination Profiles and Horizon Mask........................................ 40
24. DSS 45 Hour-Angle and Declination Profiles and Horizon Mask........................................ 41
25. DSS 46 X-Y Profiles and Horizon Mask .............................................................. 42
26. DSS 53 Hour-Angle and Declination Profiles and Horizon Mask........................................ 43
27. DSS 54 Hour-Angle and Declination Profiles and Horizon Mask........................................ 44
28. DSS 63 Hour-Angle and Declination Profiles and Horizon Mask........................................ 45
29. DSS 65 Hour-Angle and Declination Profiles and Horizon Mask........................................ 46
30. DSS 66 X-Y Profiles and Horizon Mask .............................................................. 47

Tables
Table                                                                                                 Page
1. DSN Antenna Types.................................................................................... 7
2. ITRF93 Coordinates for DSN Stations ................................................................ 11
3. ITRF93 Site Velocities for DSN Stations ............................................................ 12
4. Geocentric Coordinates for DSN Stations ............................................................ 13
5. Geodetic Coordinates for DSN Stations............................................................... 14
6. Approximate Cable Wrap Limits for Azimuth-Elevation Antennas........................................ 17


1 Introduction

1.1 Purpose
This module describes the geometry and surveillance visibility
provided by the DSN for support of spacecraft telecommunications.

1.2 Scope
This module provides the Deep Space Network (DSN) station coordinates
that are required for spacecraft navigation and to locate the stations with
respect to other points on the Earth's surface.  Coverage charts are provided to
illustrate areas of coverage and non-coverage from selected combinations of
stations for spacecraft at selected altitudes.  Horizon masks are included so
the effects of terrain masking can be anticipated.


2 General Information

2.1 Station Locations
          The following paragraphs discuss the important concepts relating to
establishing the location of the DSN antennas.

2.1.1 Antenna Reference Point
          The coordinates provided by this module refer to a specific point on
each antenna.  For antennas where the axes intersect, the reference point is the
intersection of the axes.  For antennas for which the axes do not intersect, the
reference point is the intersection of the primary (lower) axis with a plane,
perpendicular to the primary axis, and containing the secondary (upper) axis.
Table 1 lists the DSN antennas by type and provides the axis offset where
appropriate. The effect of this offset on the range observable is discussed in
module 203 of this handbook.

          The 11-m antennas are unique in that the azimuth axis is tilted from
the local vertical by a 7-degree wedge that is rotated to a position with
respect to north called the "train angle" before the start of each track.  This
causes the station location to be displaced away from the train angle along a
circular path having a radius equal to the axis offset.  The vector 
(delta_r_sub_b), which must be added to the station coordinates to compensate 
for this effect, can be derived from the train angle that is supplied to the 
user as part of the tracking data (see module 302) and the north and east 
station vectors (N and E) which are functions of the station geodetic coordinates.


Table 1. DSN Antenna Types
                                        
    Antenna Type     Station Identifiers  Primary and Secondary         Axis Offset
                                          Axes
        70-m              14, 43, 63               Az/El                     0
34-m High Efficiency      15, 45, 65               Az/El                     0
(HEF)
34-m Beam Waveguide   24, 25, 26, 34, 54           Az/El                     0
(BWG)
34-m High-speed Beam       27, 28*                 Az/El                   1.83 m
Waveguide (HSB)
        26-m              16, 46, 66                X/Y                   6.706 m
     11-m OVLBI           23, 33, 53            Tilt/Az/El                0.391 m

Az/El Antenna's azimuth plane is tangent to the Earth's surface, and antenna at 90-degrees
elevation is pointing at zenith. X/Y Primary axis (X) is aligned horizontally in an east-
west (26-m antennas) or north-south (9-m antenna) direction.  Secondary axis is aligned
vertically in a north-south (26-m antennas) or east-west (9-m antenna) plane.  Tilt/Az/El
The azimuth axis of the Az/El mount is tilted to avoid an overhead keyhole.  The direction
of tilt is fixed for each pass and results in an apparent shift in the actual station
location from the specified station location.
* DSS 28 is not presently in service.


delta r_b = -0.391cos(sigma)N -0.391sin(sigma)E   (1)

where                                            
sigma =   the train angle      

N = [ -sin(phi_g)cos(lambda)]      (2)
    [ -sin(phi_g)sin(lambda)]
    [      cos(phi_g)       ]

E = [-sin(lambda)]   (3)
    [-cos(lambda)]
    [     0      ]


phi_g = Station Geodetic Latitude (Table 5)
lambda = Station Longitude

2.1.2 IERS Terrestrial Reference Frame
          To use station locations with sub-meter accuracy, it is necessary to
clearly define a coordinate system that is global in scope as opposed to the
regional coordinate systems referenced in previous editions of this document.
The International Earth Rotation Service (IERS) has been correlating station
locations from many different services and has established a coordinate frame
known as the IERS Terrestrial Reference Frame (ITRF).  The IERS also maintains
a celestial coordinate system and coordinates delivery of Earth-orientation
measurements that describe the motion of station locations in inertial space.
The DSN has adopted the IERS terrestrial system to permit its users to have
station locations consistent with widely available Earth-orientation
information.

          The IERS issues a new list of nominal station locations each year, and
these locations are accurate at the few-cm level.  At this level of accuracy,
one must account for ongoing tectonic plate motion (continental drift), as well
as other forms of crustal motion.  For this reason ITRF position coordinates are
considered valid for a specified epoch date, and one must apply appropriate
velocities to estimate position coordinates for any other date.  Relative to the
ITRF, even points located on the stable part of the North American plate move
continuously at a rate of about 2.5 cm/yr.

          The coordinates in this module are based on the 1993 realization of
the ITRF, namely ITRF93, documented in IERS Technical Note 18 (1). ITRF93 was
different from earlier realizations of the ITRF in that it was defined to be
consistent with the Earth Orientation Parameters (EOP) distributed through
January 1, 1997.  Earlier realizations of the ITRF were known to be inconsistent
(at the 1-3 cm level) with the Earth orientation distributions.

          After ITRF93 was published, the IERS decided to improve the accuracy
of the EOP series and make it consistent with the ITRF effective January 1,
1997. This date was chosen because it enabled a defect in the definition of
universal time to be removed at a time when its contribution was zero.  In
anticipation of this change, ITRF94 and ITRF95 were made consistent with the
pre-ITRF93 definition of the terrestrial reference frame, and all prior EOP
series were recomputed in accordance with the new system.

          Until this change is fully adopted by the Earth-orientation community,
the DSN is delivering Earth-orientation calibrations to navigation teams that
are consistent with the earlier definition and using the ITRF93 reference frame.
Users interested in precise comparison with other systems should keep in mind
the small systematic differences.

2.1.2.1 ITRF Coordinates
Figure 1 illustrates the ITRF coordinates and the relationship between the ITRF
coordinates and geocentric coordinates discussed below.  The Cartesian
coordinates of the DSN station locations in the ITRF93 reference system are
provided in Table 2.  Table 2 also gives the characteristic position
uncertainty for horizontal and vertical components.

2.1.2.2 ITRF Site Velocities
The locations given in Table 2 are for the epoch 1993.0.  To
transform these locations to any other epoch, the site velocities should be
used.  Table 3 gives the ITRF93 site velocities for the DSN stations, in both
Cartesian and east-north-vertical components.

2.1.3 Geocentric Coordinates
Geocentric coordinates are used for spacecraft tracking.  They relate
the station location to the Earth's center of mass in terms of the geocentric
radius and the angles between the station and the equatorial and hour angle
planes.  Geocentric coordinates for the DSN stations are provided in Table 4.

2.1.4 Geodetic Coordinates
          Locations on the Earth's surface are defined with respect to the
geoid.  That is, the surface around or within the Earth that is normal to the
direction of gravity at all points and coincides with mean sea level in the
oceans.  The geoid is not a regular surface because of variations in the Earth's
gravitational force.  To avoid having to make computations with respect to this
non-mathematical surface, computations are made with respect to an ellipsoid
having a semi-major (equatorial) axis and semi-minor (polar) axis that provides
a best fit to the geoid in the area of interest.  The ellipsoid is uniquely
defined by specifying the equatorial radius and the flattening (that is, the
amount that the ellipsoid deviates from a perfect sphere).  The relationship
between the polar and equatorial axes is given by the following expression:

          (polar axis) = (equatorial axis) x (1 - flattening). (4)

          Once the Cartesian coordinates (x, y, z) are known, they can be
transformed to geodetic coordinates in longitude, latitude, and height with
respect to an ellipsoid (lambda, phi, h) by the following noniterative method
(Reference 2):
                                        
                                        
Figure 1. ITRF Cartesian and Geocentric Coordinate System Relationships
(Figure omitted in text-only document)

Table 2. ITRF93 Coordinates for DSN Stations Table 3. ITRF93 Site Velocities for DSN
                                    Stations
                                        
         Antenna                        Cartesian Coordinates               Uncertainty
  Name    Description           x(m)            y(m)             z(m)        h(m)     v(m)
 DSS 13     34-m R & D     -2351112.491    -4655530.714     +3660912.787     0.04     0.05
 DSS 14        70-m        -2353621.251    -4641341.542     +3677052.370     0.03     0.03
 DSS 15      34-m HEF      -2353538.790    -4641649.507     +3676670.043     0.03     0.03
 DSS 16      26-m X-Y      -2354763.158    -4646787.462     +3669387.069     0.05     0.10
 DSS 23   11-m Tilt/Az/El  -2354757.567    -4646934.675     +3669207.824     0.05     0.10
 DSS 24      34-m BWG      -2354906.495    -4646840.128     +3669242.317     0.05     0.10
 DSS 25      34-m BWG      -2355022.066    -4646953.636     +3669040.895     0.05     0.10
 DSS 26      34-m BWG      -2354890.967    -4647166.925     +3668872.212     0.05     0.10
 DSS 27      34-m HSB      -2349915.260    -4656756.484     +3660096.529     0.05     0.10
 DSS 28   Not in service   -2350101.849    -4656673.447     +3660103.577     0.05     0.10
 DSS 33   11-m Tilt/Az/El  -4461083.514    +2682281.745     -3674570.392     0.03     0.10
 DSS 34      34-m BWG      -4461146.756    +2682439.293     -3674393.542     0.05     0.10
 DSS 43        70-m        -4460894.585    +2682361.554     -3674748.580     0.03     0.03
 DSS 45      34-m HEF      -4460935.250    +2682765.710     -3674381.402     0.03     0.03
 DSS 46      26-m X-Y      -4460828.619    +2682129.556     -3674975.508     0.04     0.04
 DSS 53   11-m Tilt/Az/El  +4849330.129    -0360338.092     +4114758.766     0.05     0.10
 DSS 54      34-m BWG      +4849434.555    -0360724.108     +4114618.643     0.05     0.10
 DSS 63        70-m        +4849092.647    -0360180.569     +4115109.113     0.03     0.03
 DSS 65      34-m HEF      +4849336.730    -0360488.859     +4114748.775     0.03     0.03
 DSS 66      26-m X-Y      +4849148.543    -0360474.842     +4114995.021     0.05     0.10
Notes: 1. All antennas are AZ-EL type unless otherwise specified. 2.        
Horizontal (h) and vertical (v) uncertainties are 1-sigma.

      Complex         x(m/yr)    y(m/yr)      z(m/yr)     e(m/yr)     n(m/yr)      v(m/yr)
Goldstone (Stations   -0.0191     0.0061      -0.0047     -0.0198     -0.0057      -0.0001
1x & 2x)
Canberra (Stations    -0.0354    -0.0017      0.0412      0.0197      0.0506       0.0001
3x & 4x)
Madrid (Stations 5x   -0.0141     0.0222      0.0201      0.0211      0.0255       0.0011
& 6x)


lambda = arctan(y/x)  (5)
phi = arctan((z(1-f)+e^2*a*sin^3(mu))/((1-f)(p-e^2*a*cos^3(mu))))   (6)
h = p*cos(phi) + z*sin-a(1-e^2*sin^2(phi))^(1/2)   (7)

where:
e^2 = 2f-f^2
p = (x^2+y^2)^(1/2)
r = (p^2+z^2)^(1/2)
mu = arctan(z/p[(1-f)+e^2*a/r]
          
          Table 5 provides geodetic coordinates derived by the preceding
approach using an ellipsoid with a semi-major axis (a) of 6378136.3 m and a
flattening (f) of 298.257.

 Table 4. Geocentric Coordinates for DSN Stations
                                        
          Antenna                                      Geocentric Coordinates 
  Name        Description   Spin Radius (m)  Latitude (deg)  Longitude (deg)  Geocentric
                                                                              Radius (m)
 DSS 13       34-m R & D    5215524.535        35.0660185      243.2055430      6372125.125
 DSS 14          70-m       5203996.955        35.2443527      243.1104638      6371993.286
 DSS 15        34-m HEF     5204234.332        35.2403133      243.1128069      6371966.540
 DSS 16        26-m X-Y     5209370.715        35.1601777      243.1263523      6371965.530
 DSS 23    11-m Tilt/Az/El  5209499.503        35.1581932      243.1271390      6371967.603
 DSS 24        34-m BWG     5209482.486        35.1585349      243.1252079      6371973.553
 DSS 25        34-m BWG     5209635.978        35.1562594      243.1246384      6371983.060
 DSS 26        34-m BWG     5209766.971        35.1543411      243.1269849      6371993.032
 DSS 27        34-m HSB     5216079.244        35.0571456      243.2233516      6372110.269
 DSS 28    Not in service   5216089.176        35.0571462      243.2211109      6372122.448
 DSS 33    11-m Tilt/Az/El  5205372.367      -35.2189880       148.9830895      6371684.945
 DSS 34        34-m BWG     5205507.750      -35.2169868       148.9819620      6371693.561
 DSS 43          70-m       5205251.579      -35.2209234       148.9812650      6371689.033
 DSS 45        34-m HEF     5205494.708      -35.2169652       148.9776833      6371675.906
 DSS 46        26-m X-Y      5205075.496       -35.2235036     148.9830794      6371676.067
 DSS 53    11-m Tilt/Az/El  4862699.481        40.2375043      355.7503453      6370014.595
 DSS 54        34-m BWG     4862832.239        40.2357708      355.7459008      6370025.429
 DSS 63          70-m       4862450.981        40.2413537      355.7519890      6370051.221
 DSS 65        34-m HEF     4862717.238        40.2373325      355.7485795      6370021.697
 DSS 66        26-m X-Y     4862528.530        40.2401197      355.7485798      6370036.713
Notes: 1. All antennas are AZ-EL type unless otherwise specified.

 Table 5. Geodetic Coordinates for DSN Stations
         Antenna           latitude (phi)               longitude (lambda)          height(h)
  Name       Description    deg    min        sec      deg      min       sec          (m)
 DSS 13      34-m R & D      35     14     49.79342    243      12     19.95493     1071.178
 DSS 14         70-m         35     25     33.24518    243       6     37.66967     1002.114
 DSS 15       34-m HEF       35     25     18.67390    243       6     46.10495     0973.945
 DSS 16       26-m X-Y       35     20     29.54391    243       7     34.86823     0944.711
 DSS 23    11-m Tilt/Az/El   35     20     22.38335    243       7     37.70043     0946.086
 DSS 24       34-m BWG       35     20     23.61555    243       7     30.74842     0952.156
 DSS 25       34-m BWG       35     20     15.40450    243       7     28.69836     0960.862
 DSS 26       34-m BWG       35     20     08.48213    243       7     37.14557     0970.159
 DSS 27       34-m HSB       35     14     17.78052    243      13     24.06569     1053.203
 DSS 28    Not in service    35     14     17.78136    243      13     15.99911     1065.382
 DSS 33    11-m Tilt/Az/El  -35     24     01.76138    148      58     59.12204     0684.839
 DSS 34       34-m BWG      -35     23     54.53995    148      58     55.06320     0692.750
 DSS 43         70-m        -35     24     8.74388     148      58     52.55394     0689.608
 DSS 45       34-m HEF      -35     23     54.46400    148      58     39.65992     0675.086
 DSS 46       26-m X-Y      -35     24     18.05462    148      58     59.08571     0677.551
 DSS 53    11-m Tilt/Az/El   40     25     38.48036    355      45      1.24307     0827.501
 DSS 54       34-m BWG       40     25     32.23201    355      44     45.24283     0837.696
 DSS 63         70-m         40     25     52.34908    355      45      7.16030     0865.544
 DSS 65       34-m HEF       40     25     37.86055    355      44     54.88622     0834.539
 DSS 66       26-m X-Y       40     25     47.90367    355      44     54.88739     0850.582
Notes: 1. All antennas are AZ-EL type unless otherwise                             
specified.

2.2 Coverage and Mutual Visibility
          The coverage and mutual visibility provided for spacecraft tracking
depends on the altitude of the spacecraft, the type or types of antennas being
used, the blockage of the antenna beam by the landmask and structures in the
immediate vicinity of the antennas, and whether simultaneous uplink coverage
is required.  Receive limits are governed by the mechanical capabilities of
the antennas and the terrain mask.  Transmitter limits, on the other hand, are
based on radiation hazard considerations to on-site personnel and the general
public and are set above the terrain mask and the antenna mechanical limits.

2.2.1 Use of Transmitters Below Designated Elevation Limits
          Requests for coordination to relinquish the transmitter radiation
restrictions will be considered for spacecraft emergency conditions or for
critical mission support requirements (conditions where low elevation or high-
power transmitter radiation is critical to mission objectives). In either
event, the uplink radiation power should be selected as the minimum needed for
reliable spacecraft support.

2.2.1.1 Spacecraft Emergencies
The need for violation of transmitter radiation restrictions to
support a spacecraft emergency will be determined by the DSN.  The restrictions
will be released after assuring that appropriate local authorities have been
notified and precautions have been taken to ensure the safety of on-site
personnel.

2.2.1.2 Critical Mission Support
If critical mission activities require the transmitter radiation
restrictions to be violated, the project is responsible for notifying the DSN
through their normal point of contact three months before the activity is
scheduled.  The request must include enough information to enable the DSN to
support it before the appropriate authorities.  Requests made less than three
months in advance will be supported on a best-efforts basis and will have a
lower probability of receiving permission to transmit.  Requests will be
accepted or denied a minimum of two weeks before the planned activity.

2.2.2 Mechanical Limits on Surveillance Visibility
          All DSN antennas have areas of non-coverage caused by mechanical
limits of the antennas.  The first area is the mechanical elevation limit, which
is approximately six degrees for antennas using an azimuth-elevation mount and
somewhat lower for antennas with X-Y mounts.  A second area of non-coverage is
the area off the end or ends of the antenna's primary axis referred to as the
keyhole.

2.2.2.1 Azimuth-Elevation Antennas
          The keyhole of the DSN azimuth-elevation antennas is directly
overhead and results from the fact that the antennas can only be moved over an
arc of approximately 85 degrees in elevation.  In order to track a spacecraft
which is passing directly overhead, it is necessary to rotate the antenna 180
degrees in azimuth when the spacecraft is at zenith in order to continue the
track. Thus, the size of the keyhole depends on how fast the antenna can be
slewed in azimuth.  Specifications on antenna motion are contained in module
302, Antenna Positioning.  The location of the DSN antennas is such that
overhead tracks are not required for spacecraft on normal planetary missions.

The DSN azimuth-elevation antennas have an additional restriction on
antenna motion caused by the routing path of cables and hoses between the fixed
and rotating portions of the antenna.  This azimuth cable wrap has no effect on
surveillance visibility but does place a restriction on the time between tracks
due to the requirement to unwind the cables.  Table 6 provides the approximate
cable wrap limits for the DSN azimuth-elevation antennas.

2.2.2.2 X-Y Antennas
The DSN 26-m X-Y antennas (DSS 16, 46, and 66) have two keyholes
caused by requirements for mechanical clearance in the antenna structure.  The
keyholes are located directly to the east and west of the 26-m antennas.

2.2.2.3 Tilt-Azimuth-Elevation Antennas
The DSN 11-m antennas (DSS 23, 33, and 53) have a keyhole above each
antenna, which is offset from zenith by 7-degrees.  The location of this keyhole
is set before each pass to a position that will provide clearance between the
keyhole and the scheduled track.

2.2.3 Coverage Charts
          The following figures provide examples of coverage for various
combinations of stations, spacecraft altitudes, and type of support.  These
figures were plotted by a program written as a collection of Microsoft Excel
97/98 macros.  This program is available for download
(1.7 Mbytes) from the 810-005 web site
(http://eis.jpl.nasa.gov/deepspace/dsndocs/810-005/).

2.2.3.1 70-m Subnet Receive Coverage of Planetary Spacecraft
          Figure 2 illustrates the receive coverage of planetary spacecraft by
the DSN 70-m antenna subnet. The small ovals at each antenna location on the
figure represent the 70-m antenna keyholes above each station and are
approximately to scale.


Table 6. Approximate Cable Wrap Limits for Azimuth-Elevation Antennas
                                        
                   Antenna                             Azimuth Position (Degrees)
         Name(s)              Description   Center of Wrap        CW Limit      CCW Limit
        DSS 14, 63               70-m               45              310            140
          DSS 43                 70-m              135               40            230
        DSS 15, 65             34-m HEF            135              360            270
          DSS 45               34-m HEF             45              270            180
  DSS 24, 25, 26, 54, 65       34-m BWG            135              360            270
          DSS 34               34-m BWG             45              270            180
          DSS 27               34-m HSB            135              360            270
      DSS 23, 33, 53             11-m               0               380          (-)380

2.2.3.2 70-m Subnet Transmit Coverage of Planetary Spacecraft
Figure 3 illustrates the transmit coverage of planetary spacecraft by
the DSN  70-m antenna subnet using a 10.4-degree transmit elevation limit at
DSS 14 and a 10.2-degree transmit elevation limit at DSS 43 and DSS 63. The
small ovals at the antenna locations on the figure represent the 70-m antenna
keyholes.  The reduced coverage to the west of DSS 63 is caused by the need to
have a 20.2-degree elevation limit to protect the high ground to the northwest
of the station.

2.2.3.3 34-m HEF Subnet Receive Coverage of Planetary Spacecraft
Figure 4 illustrates the receive coverage of planetary spacecraft by
the DSN 34-m HEF antenna subnet.  The keyhole above each 34-m HEF antenna is
very small and is somewhat exaggerated for clarity on the maps.  This chart is
very similar to Figure 2 but is included to show that the location of DSS 65
shifts the apparent position of the high ground to the north and west of where
it is observed from DSS 63.

2.2.3.4 34-m HEF Subnet Transmit Coverage of Planetary Spacecraft
Figure 5 illustrates the transmit coverage of planetary spacecraft by
the DSN  34-m HEF antenna subnet using a 10.6-degree transmit elevation limit at
DSS 15, a 10.5-degree transmit limit at DSS 45, and a 10.3-degree limit at DSS
65.  As is the case in Figure 4, the size of the circles used to indicate the
keyholes on the map are larger than the actual size of the 34-m HEF antenna
keyholes.  Protection of the high ground at DSS 65 is provided by disabling the
transmitter between 327.4 and 358.6 degrees azimuth.

2.2.3.5 34-m BWG Antennas Receive Coverage of Planetary Spacecraft
Figure 6 illustrates the receive coverage of planetary spacecraft by
the DSN 34-m BWG antennas.  As is the case with the other 34-m antennas, the
size of the circles on the map is larger than the actual size of the antenna
keyholes.  This chart is very similar to Figures 2 and 4 but is included to show
that the location of DSS 54 shifts the apparent position of the high ground even
further to the north and west of where it is observed from DSS 63 than is the
case with the DSS 65 34-m HEF antenna.

2.2.3.6 34-m BWG Antennas Transmit Coverage of Planetary Spacecraft
Figure 6 illustrates the transmit coverage of planetary spacecraft by
the DSN  34-m BWG antennas.  As is the case with the other 34-m antennas, the
size of the circles on the map is larger than the actual size of the antenna
keyholes.  Protection of the high ground at DSS 54 is provided by disabling the
transmitter between 267 and 3 degrees azimuth.

2.2.3.7 26-m Subnet Receive Coverage of Earth Orbiter Spacecraft
          Figure 8 illustrates the receive coverage of Earth-orbiter spacecraft
at altitudes of 200 km, 1000 km, and 5000 km by the DSN 26-m antenna subnet.
This chart can also be used when the 34-m HSB antenna, DSS 27, is substituted
for the Goldstone 26-m antenna.  DSS 27 is collocated with an inactive antenna,
DSS 28, approximately 14.5 km southeast of DSS 16.  The inactive antenna blocks
reception to the west in the same place and approximately to the same extent as
the west keyhole of DSS 16.

2.2.3.8 26-m Subnet Transmit Coverage of Earth Orbiter Spacecraft
Figure 9 illustrates the transmit coverage of Earth-orbiter
spacecraft at altitudes  of 200 km, 1000 km, and 5000 km by the DSN 26-m
antenna subnet.  This chart is similar to Figure 8.  However, the limits
placed on transmitter operation in order to clear terrain and structures are
clearly visible.

2.2.3.9 34-m BWG Antennas Receive Coverage of Earth Orbiter Spacecraft
Figure 10 illustrates the receive coverage of Earth-orbiter spacecraft
by the DSN 34-m BWG antennas at altitudes of 500 km, 5000 km, and geosynchronous
altitude (35789 km).  As is the case with the other 34-m antennas, the size of
the circles on the map is larger than the actual size of the antenna keyholes
2.2.3.10 34-m BWG Antennas Receive Coverage of Earth Orbiter Spacecraft

Figure 11 illustrates the transmit coverage of planetary spacecraft
by the DSN 34-m BWG antennas.  As is the case with the other 34-m antennas, the
size of the circles on the map is larger than the actual size of the antenna
keyholes.  Protection of the high ground at DSS 54 is provided by disabling the
transmitter between 267 and 3 degrees azimuth.

2.2.3.11 11-m Subnet Receive Coverage
Figure 12 illustrates the receive coverage of the 11-m Orbiting Very-
long Baseline Interferometry (OVLBI) subnet at 5000 km, geosynchronous altitude
(35789 km), and planetary range.  The irregular coverage outlines are the result
of high ground to the east of DSS 33 and northwest of DSS 54 plus blockage due
to other antennas and structures at each complex.

2.2.4 Horizon Masks and Antenna Limits
          Figures 13 through 30 show the horizon mask and transmitter limits for
all DSN stations.  The transmitter limits are identified as the L/P (low power)
transmitter mask (or the H/P (high power) transmitter mask depending on the type
of transmitter that is available. Only the 70-m stations have both L/P and H/P
transmitters, and DSS 43 is the only station that uses different H/P and L/P
transmitter limits. At DSS 43, the H/P transmitter limit is set at 10.4 degrees
whereas the L/P transmitter limit is set at 10.2 degrees. DSS 14 uses a 10.4-
degree limit for both transmitters, and DSS 63 uses a 10.2-degree limit except
to the northwest of the station where it is set to 20.2 degrees.  These masks
and limits are the ones used to establish the coverage depicted in Figures 2
through 11.  Each chart shows antenna coordinates in two coordinate systems.
For all antennas except those with X-Y mounts, the coordinate systems are
azimuth-elevation and hour angle-declination.  The antennas with X-Y mounts show
azimuth-elevation and X-Y coordinates.

          Charts showing hour angle-declination coordinates can be used to
provide an elevation profile (for estimating antenna gain and noise
temperature) for spacecraft at planetary distances where the declination
remains constant for an entire tracking pass.  The hour angle curves on these
charts have been spaced at increments of 15 degrees so that pass length may
conveniently be estimated.  These figures were plotted by a program written as
a collection of Microsoft Excel 97/98 macros.  This program is available for
download (1.1 Mbytes) from the 810-5 web site
(http://eis.jpl.nasa.gov/deepspace/dsndocs/810-005/).  This file also contains
the land mask data, which can be used to accurately calculate spacecraft rise
and set times.


3 Proposed Capabilities

3.1 70-m X-band Uplink Implementation
An X-band transmit capability is being added to the 70-m antenna
subnet.  The X-band transmit coverage will be the same as is presently
depicted in Figure 3.

3.2 34-m BWG Ka-band Implementation
          A Ka-band receive capability is being added to all 34-m BWG
antennas.  The Ka-band receive coverage will be the same as is presently
depicted in Figure 6.


Figure 2. DSN 70-m Subnet Receive Coverage, Planetary Spacecraft
(Figure omitted in text-only document)

Figure 3. DSN 70-m Subnet Transmit Coverage, Planetary Spacecraft                                       
(Figure omitted in text-only document)

Figure 4. DSN 34-m HEF Subnet Receive Coverage, Planetary Spacecraft
(Figure omitted in text-only document)

Figure 5. DSN 34-m HEF Subnet Transmit Coverage, Planetary Spacecraft
(Figure omitted in text-only document)

Figure 6. DSN 34-m BWG Antennas Receive Coverage, Planetary Spacecraft
(Figure omitted in text-only document)

Figure 7. DSN 34-m BWG Antennas Transmit Coverage, Planetary Spacecraft
(Figure omitted in text-only document)

Figure 8. DSN 26-m Subnet Receive Coverage, Earth Orbiter Spacecraft
(Figure omitted in text-only document)

Figure 9. DSN 26-m Subnet Transmit Coverage, Earth Orbiter Spacecraft
(Figure omitted in text-only document)

Figure 10. DSN 34-m BWG Antennas Receive Coverage, Earth Orbiter Spacecraft
(Figure omitted in text-only document)

Figure 11. DSN 34-m BWG Antennas Transmit Coverage, Earth-Orbiter Spacecraft
(Figure omitted in text-only document)        

Figure 12. DSN 11-m Subnet Earth-Orbiter and Planetary Receive Coverage
(Figure omitted in text-only document)
                                        
Figure 13. DSS 14 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 14. DSS 15 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 15. DSS 16 X-Y Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 16. DSS 23 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
                 
Figure 17. DSS 24 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)
                 
Figure 18. DSS 25 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 19. DSS 26 Hour Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 20. DSS 27 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 21. DSS 33 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 22. DSS 34 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 23. DSS 43 Hour Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 24. DSS 45 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 25. DSS 46 X-Y Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 26. DSS 53 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 27. DSS 54 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 28. DSS 63 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 29. DSS 65 Hour-Angle and Declination Profiles and Horizon Mask
(Figure omitted in text-only document)

Figure 30. DSS 66 X-Y Profiles and Horizon Mask
(Figure omitted in text-only document)


Appendix A
References

1  C. Boucher, Z. Altamimi, and L. Duhem, Results and analysis of the ITRF93,
   IERS Technical Note 18, Observatoire de Paris, October 1994
2  B. R. Bowring, "The accuracy of geodetic latitude and height equations,"
   Survey Review, 28, pp. 202-206, 1985.