Continuous-wave (CW) and laser range-gate (LRG) imaging are two effective imaging modes for long-range target acquisition and object discrimination. Continuous wave time-of-flight (CWToF) and LRG with range resolve (LRGRR) are modulated versions of CW and LRG that produce 3D imagery of the target. In this study, the sensitivity and range resolution benefits of these four systems are quantified. A performance model is developed and used to compare trade-offs between range resolution and sensitivity for the four active imaging techniques presented. It is found that the LRG-based systems deliver increased performance over the CW-based systems due to higher sensitivity in nighttime circumstances and in degraded visual environments. The results will enable systems engineers to discern whether the added complexity associated with CWToF and LRGRR imaging is worth implementing over traditional approaches such as CW and LRG.