antenna of chang'e 5 ascent module

There are 3 poles on the left side of ascent module, and 2 poles on right side.

 It looks like spatial diversity antenna, or conical spiral logarithmic antenna

 

the purpose may be used for positioning, eg, during rendezvous docking. The ascent module has to dock with orbiter very precisely, on the scale of centimeter, or millimeter.

>>> RF ranging. Minmum 2 antenna rods needed for ranging. 3 rods can make 3 measurements same time, to increase accuracy.

Upon successful capture of ascent module, the moon samples can then be transferred to re-entry capsule ( located inside the orbiter) 

or it is a periscope( backup periscope bck-4), as in soyuz spacecraft ?

is it RF metrology antenna or FFRF (formation flying Radio Frequency) sensor in PRISMA 

from France , Swedish Space Corp or CNES? the main purpose is for automatic rendezvous of two spacecrafts

 

If it is really a FFRF for rendezvous, why are they mounted on one side of spacecraft, rather than the "mating" side?

TT&C antenna?

Reference:

eoportal

Space tracking note

ESA: grip on antenna 

a high-gain antenna is particularly good at transmitting signals in a narrow beam whereas a low-gain antenna tends to send its signal in a much wider sweep of directions.

Because a low-gain antenna spreads its power out over a wider volume in space, the signal received by a ground station is weaker. This signal cannot carry as much information as a high-gain signal where the available power is concentrated to beam the signal accurately back to its target. Dish-shaped antennas are particularly good at focusing radio beams and so make excellent high-gain antennas.

Spacecraft always carry both high- and low-gain antennas. Although the high-gain antenna is used to return the majority of the data collected, if the spacecraft has to turn even a little, the high-gain signal could miss the Earth. The low-gain antenna does not suffer from such a problem because it transmits over a wider volume.

So even though they transmit and receive at slower rates, low-gain antennas are used to take over as back-ups when the high-gain antenna cannot be used. Spacecraft normally carry two of them on opposite sides. That way, they provide total coverage around the spacecraft.

Low-gain antennas are essential in critical situations. For example, if a spacecraft lost the ability to point itself, the low-gain antenna will always receive signals from Earth, allowing engineers to begin fixing the problem.

Chang'e 6