Understanding Range Resolution and the Nyquist Theorem in SkyRadar’s 8 GHz Pulse Radar

In radar engineering, range resolution expresses how precisely a radar can distinguish between two targets located at different distances along the beam path. It is a direct measure of the system’s spatial precision — and one of the fundamental indicators of radar performance.

The range resolution ΔR is determined by the bandwidth (B) of the transmitted pulse according to the classical radar relation:

ΔR = c / (2B)

where c is the speed of light (approximately 3×10⁸ m/s).

For SkyRadar’s NextGen Pulse Radar, which operates at a center frequency of 8 GHz and a bandwidth of 1.4 GHz, the theoretical range resolution becomes:

or roughly 10.7 cm, perfectly matching the measured resolution of 10.6 cm. This close agreement shows that the radar achieves its theoretical design limit, a result of precise pulse shaping and accurate signal processing.

In practical terms, the radar can separate two reflecting objects if they are at least 10.6 cm apart in range. Objects closer than that will merge into a single return echo.

To capture such fine resolution digitally, the radar’s sampling process must satisfy the Nyquist theorem, which states that a signal must be sampled at least twice per cycle of its highest frequency component. Translated into radar terminology, this means that the digital range sampling must include at least two range cells per resolvable distance interval to reconstruct the echo without ambiguity or aliasing.

SkyRadar’s system provides 180 range cells in total. Following Nyquist’s criterion, these correspond to 90 resolvable distance intervals, each representing an independent slice of measurable space. With a range resolution of 10.6 cm, the overall range window thus extends to approximately:

90 × 0.106 m = 9.54 m.

This roughly 10 m observation window is ideal for short-range laboratory environments, where students can observe reflections, attenuation, and signal behavior in real time.

The configuration illustrates how bandwidth and sampling density jointly define radar precision. The 1.4 GHz bandwidth determines how small a spatial difference can be resolved, while the sampling architecture ensures that each resolvable interval is captured with two discrete samples — fully compliant with the Nyquist theorem.

For educational and research applications, this provides a clear and measurable example of radar theory in action. Trainees can vary parameters such as pulse length or sampling rate and directly observe the impact on range resolution and target discrimination.

In summary, SkyRadar’s 8 GHz Pulse Radar demonstrates how signal theory and digital processing converge in modern radar design. With its 1.4 GHz bandwidth, 10.6 cm resolution, 180 range cells, and 90 resolvable intervals, it offers a precise and intuitive illustration of the Nyquist sampling principle applied to radar range measurement.