ncodf=1   radar observation
ncodf=2   transponder
ncodf=3   differential radar observation (decampli aug 1973)
(feature relative to subradar point if nspot.gt.0)
ncodf=19  les-8/9 one way doppler count observable
(first point of observation series is reference,
no effect on orbit fit) (ncode must be 1)

mocpar = 0 compar called in midst of least squares iteration
read all three data sets iobcon, iobs, iabs1 which become in
subroutines of compar iiobcn, iiobs, iiabs1
mocpar = 1 compar called at end of least squares iteration to
calculate dummy observations
read only iobcon which become in subroutines of compar iiobcn

dstf(1) =ctrecf=coordinate time at reception (fraction of day)
dstf(2) = longitude of subradar point (deg)
dstf(3) = latitude of subradar point (deg)
dstf(4) = time delay from receive to reflection (sec)
dstf(5) = longitude of observed spot away from subradar point
if spot name='&&&&' and nspot=0 (deg)
dstf(6) = latitude of observed spot away from subradar point
if spot name='&&&&' and nspot=0 (deg)
dstf(10)= fdev =1+fractional frequency offset from atomic
time for unit of time delay measurement

nprec  = 0 nutation-precession determined midway between
receiving and sending times
nprec  = 1 nutation-precession determined at both receiving and
sending times

ndprec = 0 derivative of nutation-precession matrix not used in
determining velocities
ndprec = 1 derivative of nutation-precession matrix used in
determining velocities

ntmdly =-1 classical determination of time delay
ntmdly = 0 special relativistic determination of time delay
(same as classical because deviation of earth
velocity from its average is small)
ntmdly = 1 general relativistic determination of time delay
ntmdly = 2 general rel., including effect of earth

ndop   =-1 classical determination of doppler shift
ndop   = 0 special relativistic determination of doppler shift
(same as classical because deviation of earth
velocity from its average is small)
ndop   = 1 general relativistic determination of doppler shift

nmedia =-1 effect of interplanetary media on radar signal is
ignored
nmedia = 0 effect of interplanetary media on time delay only is
included
nmedia = 1 effect of interplanetary media on time delay and
doppler shift is included

neatm  =-1 effect of earth atmosphere on radar signal is
ignored
neatm  = 0 effect of earth atmosphere on time delay only is
included
neatm  = 1 effect of earth atmosphere on time delay and doppler
shift is included

npatm  =-1 effect of planet atmosphere on radar signal is
ignored
npatm  = 0 effect of planet atmosphere on time delay only is
included
npatm  = 1 effect of planet atmosphere on time delay and
doppler shift is included

calcvl = -1,0 don't calculate transponder and relative
velocities unless needed for doppler
calcvl = 1    calculate velocities (needed for either ctvary
partial or light time iteration correction)

savb(i,1), i=1,numsav,  saved precession-nutation,etc. from input
observation library tape for radar, optical
and first part of transit observation
savb(i,2) i=1,numsav   these saved quantities from iiobs

resltb(1,j) = time delay for radar observation (seconds)
right ascension for optical observation (sec.of time)
time that first limb of planet cuts first limb of sun
for transit observation (first part) (seconds)
resltb(2,j) = doppler shift for radar observation (cycles/sec)
declination for optical observatoon (sec.of arc)
time that second limb of planet cuts first limb of sun
for transit observation (first part) (seconds)

set up observation data set quantities
niobc,niobs,niabs1  indicate status of data sets  iiobc,
iiobs, iiabs1
-1  not to be read
0  ready to be read
1  already read
if  iiobc, iiobs, or iiabs1  are initially zero,  data set
is not read in any case.

calculate obscon(1)
obscon(1)=(uplink freq/exciter freq. ) typically 96.
obscon(2)=obscon(1)*turnaround ratio
turnaround ratio=240/221  s band
880/221  x band

if observed spot name is '&&&&', spots away from subradar point
are observed with input longitude and latitude on observation card
in fields 58-65,66-72 instead of at-uts,ut-uts. this longitude and
latitude away from the subradar point  are in dstf(5),dstf(6)
if observation is from observation library tape. if from
observation card data in fields 58-65,66-72 are moved into
dstf(5),dstf(6).

setup longitude and latitude of observed spot for radar
observations away from the subradar point in case that
observations are from cards (ib=1). if observations from
observation library tape, dstf(5),dstf(6) setup in
subroutine obsred

idopob is set to 0 in radar before radctl called
if this is phase delay doppler observable, radctl sets up
for start of counting interval and calls mdeldp or sbdldp for
calculations. upon return from these routines radctl sets idopob=1
and returns to radar. if idopob=1 radar calls partl to calculate
partials at start of counting interval. then radar calls radctl
again, which if idopob=1 sets idopob=-1 and does calculations at
end of counting interval. upon return to radar usual things are
done and partl called a second time (actually first time if not
phase delay doppler observable) to evaluate partials at the end
of the counting interval. the partials of the phase delay doppler
observable are the difference of the two calculations times the
frequency divided by the counting interval.
this first pass through partial is eliminated in radctl if the
begin time of the current observation is the same as the final
time of the previous observation. in this case old information
is merely updated