jmbrooks,
Here's a useful link with all the info you wanted (or didn't want) to know about the USGS 3DEP lidar base specifications.
https://www.usgs.gov/ngp-standards-and- ... e-contentsRegarding nominal pulse spacing and vertical accuracy, see this link:
https://www.usgs.gov/ngp-standards-and- ... ion-tablesThe USGS is wanting to fill the CONUS and Hawaii with Quality Level 2 lidar data (Alaska will be covered by interferometric synthetic-aperture radar).
Regarding coordinate systems/datums, see here:
https://www.usgs.gov/ngp-standards-and- ... nts#datumsFor the vertical datum, they were first required to use GEOID12 iterations, but are now going with GEOID18 which differs from the former by less than a couple centimeters.