I'm researching photogrammetry with P3A and here is where I am stuck:     -DJI GO no longer offers waypoint flying.
     -Litchi app seems more geared towards video, but does offer waypoints.
     -Autopilot app (iOS) seems more geared towards video as well.

Is there a good app that offers waypoint flying and allows me to take picture say every 1 second?  I have read that the Phantom simpy cannot write RAW or JPEG to the SD card that quickly, with 3 seconds being the min. time between image capture.

I want to utilize the pictures in a software such as Pix4d or Agisoft to create point clouds, DTMS, and georefenced images for surveying applications.  

There are several options that do this easily.
Look at DroneDeploy, MapsMadeEasy, Pix4D etc

Here is an example of a MapsMadeEasy
https://www.mapsmadeeasy.com/map ... 5eea69acc79cb3c4456
Very easy to program, small maps are free to process.

Hi,  KlauGeomatics has announced a new PPK GPS technology for accurate aerial surveying using DJI drones without placing ground targets. See https://www.veritypositioning.com/ for more details.

Adam_Geomatics Posted at 2018-1-4 17:48
Hi,  KlauGeomatics has announced a new PPK GPS technology for accurate aerial surveying using DJI drones without placing ground targets. See https://www.veritypositioning.com/ for more details.

You are advertising (which is not permitted) under false pretences, none of your kits are designed for any of the DJI consumer aircraft, and this forum is only for those types.