Trimble R $10$ receiver is necessary $($unavoidable$)$ if you want to take GNSS

observations for precise location of points inside IIT Kanpur campus.

It is necessary to maintain the lock in Pseudo kinematic mode of GNSS observations.

By combining L$1$ and L$2$ carrier waves, we can remove the tropospheric delay.

Loss of lock does not affect pseudo range measurement.

GLONASS, BeiDOU and GALILEO have the same number of orbits and Satellites.

Mask angle technique is used to mitigate multipath, atmospheric and attenuation

errors.

The ambiguity term $N$ does not change from the moment the lock is achieved

between the satellite and the receiver.

Post processed DGPS corrections are better than the real time DGPS corrections $.$

The navigation code is modulated both on L$1$ and L$2$ carrier waves.

Once a receiver is locked on to a satellite it helps the receiver to acquire signals of

other satellites also.

The two GPS carrier waves L$1$ and L$2$ are radio waves too.

We get the $\text{'}$ beat frequency' if we combine the two signals from different

frequencies.

As regards GPS observations, the term Precision and Accuracy means the same.

Differential GPS accuracy is concerned only with improving GPS pseudo range

accuracy.

Ionospheric delay is greater at the zenith than at the horizon STATE WHETHER THESE STATEMENTS ARE TRUE OR FALSE WITH APPROPRIATE REASON