SNR, which increases as the square root of the number of dates, is comparable to the number of pixels that images can place on a target.
Click here for plots of predictions of single-date SNR as a function of asteroid size, distance, and declination, for Arecibo and Goldstone.
These calculations assume a radar cross section equal to 10% of the target cross section, a four-hour rotation period, a diffuse scattering law, and an equatorial view. SNR equals the received power of an optimally filtered echo in units of the r.m.s. receiver noise fluctuation.
| Average Number of Objects per Year with Single-Date SNR Greater than | ||||
| 20 | 100 | 1000 | 5000 | |
|---|---|---|---|---|
| Main-Belt Asteroids | ||||
| Before upgrade | 0.5 | 0.0 | 0.0 | 0.0 |
| After upgrade | 35 | 5 | 0 | 0 |
| Near-Earth Asteroids | ||||
| Before upgrade, using actual statistics since 1980 | 3 | 0.9 | 0.3 | 0.1 |
| After upgrade, with current NEA pool | 10 | 6 | 2 | 0.6 |
| After Spaceguard Survey (lower bounds): | ||||
| 1 km or larger | 80 | 20 | 10 | 4 |
| 300 m or larger | 160 | 80 | 20 | 7 |
| Science Expectation | ||||
| disc-integrated properties: | |---> | |||
| ~30-parameter shape model: | |--> | |||
| identify binary system: | |---> | |||
| ~100-parameter shape model: | |---> | |||
| see craters clearly: | |---> | |||
Asteroid Radar Research