Final answer:
The ARSR-4's frequency range is not provided in the question. However, other technologies operate at various frequencies from 880 MHz for 4G to 5.8 GHz for toll sensors. The resolution of a 500-MHz radar signal relates to the wavelength, suggesting detail in the range of wavelengths is observable, but specifics depend on additional system factors.
Step-by-step explanation:
The air route surveillance radar model 4 (ARSR-4) does not have a publicly specified frequency range in the provided question text. Typically, surveillance radars operate within certain bands of the spectrum. Other technologies mentioned, such as 4G cellular telephone signals, operate at approximately 880 MHz, while GPS signals operate at 1.228 and 1.575 GHz, Wi-Fi at 2.4 to 5 GHz, and highway toll sensors at 5.8 GHz. If we consider the frequency range for similar applications, the ARSR-4 might operate in a comparable range, however without explicit information, we cannot provide a confident answer.
As for the smallest observable detail utilizing 500-MHz radar, the question does not provide enough details to determine this precisely. However, it's worth noting that the resolution of a radar system is dependent on the wavelength of the signal; with radar, shorter wavelengths can provide finer detail. A 500-MHz signal has a wavelength of approximately 60 centimeters (assuming a speed of light of 3×108 m/s), which might suggest the resolution is in that order of magnitude, but other factors like the radar's hardware and processing capabilities also affect resolution.