A system for calculating a metric of Super-cooled Large Droplets, SLDs, in a cloud atmosphere, the system comprising: an optical source configured to divergently project first and second pulses of optical energy about an optical axis; an optical control module configured to receive at least a portion of each of the first and second divergently projected pulses of optical energy and to direct the received portion of each of the first and second divergently projected pulses within a projection range; a collimator lens located within the projection range of the optical control module and configured to collimate a portion of each of the first and second pulses of optical energy directed by the optical control module therethrough into a cloud atmosphere; an optical window located within the projection range of the optical control module and configured to transmit an uncollimated portion of each of the first and second pulses of optical energy directed by the optical control module therethrough into a cloud atmosphere; and an optical detector configured to detect and to generate first and second signals indicative of each of the first and second pulses of optical energy, respectively, backscattered by the cloud atmosphere; characterized by a processor configured to calculate, based on scintillation spike differences between the optical pulses of different collimated/uncollimated ratios, a metric of SLDs in the cloud atmosphere, wherein the calculated metric is a water droplet size distribution, ice/liquid ratio, average droplet size, and/or density of SLDs; wherein a difference between a first ratio and a second ratio is greater than 0.1, wherein the first ratio is a ratio between the collimated and uncollimated portions of the first pulse of optical energy, and the second ratio is a ratio between the collimated and uncollimated portions of the second pulse of optical energy. an optical source configured to divergently project first and second pulses of optical energy about an optical axis; an optical control module configured to receive at least a portion of each of the first and second divergently projected pulses of optical energy and to direct the received portion of each of the first and second divergently projected pulses within a projection range; a collimator lens located within the projection range of the optical control module and configured to collimate a portion of each of the first and second pulses of optical energy directed by the optical control module therethrough into a cloud atmosphere; an optical window located within the projection range of the optical control module and configured to transmit an uncollimated portion of each of the first and second pulses of optical energy directed by the optical control module therethrough into a cloud atmosphere; and an optical detector configured to detect and to generate first and second signals indicative of each of the first and second pulses of optical energy, respectively, backscattered by the cloud atmosphere; a processor configured to calculate, based on scintillation spike differences between the optical pulses of different collimated/uncollimated ratios, a metric of SLDs in the cloud atmosphere, wherein the calculated metric is a water droplet size distribution, ice/liquid ratio, average droplet size, and/or density of SLDs; wherein a difference between a first ratio and a second ratio is greater than 0.1, wherein the first ratio is a ratio between the collimated and uncollimated portions of the first pulse of optical energy, and the second ratio is a ratio between the collimated and uncollimated portions of the second pulse of optical energy.