What is radar range width (range resolution)?

Radar range width, also called range resolution, is the minimum distance between two targets that allows a radar system to distinguish them as separate objects. It is determined by the radar pulse width (τ) using the formula: ΔR = c × τ / 2, where c is the speed of light (3×10⁸ m/s) and τ is the pulse duration in seconds. A shorter pulse width gives finer range resolution.

What is the radar range width formula?

The radar range resolution (range width) formula is ΔR = (c × τ) / 2, where ΔR is the range resolution in metres, c is the speed of light (299,792,458 m/s ≈ 3×10⁸ m/s), and τ is the pulse width in seconds. For example, a pulse width of 1 µs gives ΔR = (3×10⁸ × 1×10⁻⁶) / 2 = 150 m.

What is unambiguous range in radar?

The unambiguous range (also called maximum unambiguous range) is the maximum distance a radar can measure without range ambiguity. It is calculated as: R_ua = c / (2 × PRF), where PRF is the pulse repetition frequency in Hz. At this range, the echo from one pulse returns before the next pulse is transmitted, preventing false target readings.

How is radar swath width calculated?

Radar swath width (W) for a side-looking aperture radar is: W = (c × τ) / (2 × sin θ), where θ is the incidence angle and τ is the pulse width. For beam-limited swath calculations, W ≈ R × θ_az where R is slant range and θ_az is the azimuth beam width. This calculator supports both pulse-width and incidence-angle based swath computations.

How do I use the bulk radar range width calculator?

For single mode: enter pulse width (τ) in microseconds, PRF in Hz, optional incidence angle, and click Calculate. For bulk mode: upload a TXT/CSV with one entry per line in the format: pulse_width_us,PRF_Hz,incidence_angle_deg. Leave incidence angle blank or 0 to skip swath calculation. Download results as CSV.

Radar Range Width Calculator

Features

Everything You Need for Radar Range Analysis

From single parameter entry to bulk dataset processing — all in one free tool.

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Live Preview

See range resolution, unambiguous range, and swath width update in real time as you type — before clicking Calculate.

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Bulk CSV/TXT Upload

Process hundreds of radar parameter sets simultaneously by uploading a plain-text file or pasting data directly.

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6 Output Metrics

Range resolution, pulse width, PRF, PRI, unambiguous range, and swath width computed together per entry.

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Real-Time Validation

Instant input validation with descriptive error messages catches physically impossible values before calculation.

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Export Results

Download results as CSV, copy to clipboard, or clear and start fresh. Full results table with status badges.

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Multi-Unit Support

Enter pulse width in µs or ns, PRF in Hz or kHz, and receive range outputs in metres or kilometres.

How It Works

Four Steps to Radar Range Width Analysis

1

Enter Pulse Width

Input the radar pulse duration τ in microseconds. This is the primary parameter determining range resolution — a shorter pulse gives finer resolution.

2

Enter PRF & Angle

Provide the Pulse Repetition Frequency in Hz. Optionally add the incidence angle in degrees to compute swath width for side-looking radar systems.

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Review Live Results

The live preview instantly shows range resolution, unambiguous range, PRI, and swath width as you type — no button press needed.

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Export & Use

Download results as CSV or copy to clipboard. For batch analysis, upload a TXT/CSV file and process entire parameter sweeps at once.

Radar Range Width Calculator: Complete Guide to Pulse Width & Range Resolution

Radar range width — more precisely termed range resolution — is a fundamental performance parameter of any radar system. It defines the minimum separation between two targets along the radial dimension that allows the radar receiver to distinguish them as distinct objects rather than a single merged return. Understanding and calculating range width is critical for radar system design, remote sensing, and signal processing applications.

What is Radar Range Width?

The range width (ΔR) depends directly on the transmitted pulse duration. When a short electromagnetic pulse strikes two targets at slightly different ranges, the reflected echoes overlap in time if the targets are too close together. Only when the range difference exceeds the range resolution cell can the two echoes be separated. This is governed by the formula: ΔR = (c × τ) / 2, where c is the speed of light (≈ 3 × 10⁸ m/s) and τ is the pulse width in seconds.

Key Radar Range Width Formulas

The core equations used by this calculator are:

Range Resolution: ΔR = (c × τ) / 2
Unambiguous Range: R_ua = c / (2 × PRF)
Pulse Repetition Interval: PRI = 1 / PRF
Swath Width (pulse-limited): W = (c × τ) / (2 × sin θ)

Practical Examples

For a weather surveillance radar with τ = 1 µs and PRF = 1000 Hz: range resolution ΔR = 150 m, unambiguous range R_ua = 150 km, PRI = 1 ms. For a high-resolution imaging radar with τ = 0.1 µs: ΔR = 15 m — ten times finer resolution at the cost of a lower average transmitted power. For a SAR system with θ = 30° and τ = 0.5 µs: swath width W ≈ 150 m. These values illustrate the fundamental trade-off radar engineers navigate between range resolution, maximum unambiguous range, and average power requirements across meteorological, military, and Earth observation radar systems.

Usage & Applications

This online radar range width calculator is used by RF engineers, signal processing researchers, remote sensing analysts, and engineering students to rapidly prototype radar parameters, perform sensitivity analyses, validate system specifications, and process bulk parameter sweeps without requiring specialised simulation software.

FAQ

Frequently Asked Questions

Radar range width is the minimum distance between two targets for the radar to resolve them as separate objects. It is calculated as ΔR = (c × τ) / 2, where c ≈ 3×10⁸ m/s and τ is the pulse width in seconds. A 1 µs pulse gives 150 m range resolution.

ΔR = (c × τ) / 2, where ΔR is in metres, c is 299,792,458 m/s, and τ is pulse width in seconds. For pulse width in µs: ΔR (m) = 150 × τ (µs). For example, τ = 2 µs gives ΔR = 300 m.

The maximum unambiguous range R_ua = c / (2 × PRF) is the furthest distance the radar can measure without range ambiguity. If a target is beyond this range, its echo arrives after the next pulse is sent, causing the radar to misinterpret the range. Lower PRF gives greater unambiguous range.

For a pulse-limited side-looking radar, swath width W = (c × τ) / (2 × sin θ), where θ is the incidence angle. At θ = 30° and τ = 1 µs, W = 300 m. Wider swaths require longer pulses or pulse compression techniques.

Upload a TXT or CSV file with one entry per line using the format: pulse_width_µs,PRF_Hz or pulse_width_µs,PRF_Hz,incidence_angle_°. You can also paste data directly into the text area. Click Process Bulk, then download results as CSV or copy to clipboard.