Hello, I’ve been testing a couple Reach RS units, in PPK mode, that we plan to use for collecting GCPs for drone work. We are doing simple static point collects and then post processing back in the office.
What I have found is that 7-10 minutes is required to resolve integer ambiguities and get a fixed solution. This is fine and is typical of many L1 Survey GPS units. However, what is brutal, for example, is that after the first point is collected (raw logging is started and then stopped) the next point must also be collected for 7-10 minutes to achieve a fixed solution. ARG. What I had hoped for was that the “lock” from the first point would be maintained and then that a simple 15 sec collect would / should result in a fixed solution, assuming lock is not lost. But this is not the case, as the solution is float.
So from what I am seeing if one wants a fixed solution then 10 minute occupations, at a minimum, are required. Well, if I am going to collect 20+ gcps then this is not a viable solution. 20 gcps would be over 3 hours of collection time, not to mention the time walking to each point. If lock could be maintained then 15 second collects for 20 gcps would be a total of 5 minutes spent collecting gcps!!
So… This is what I think, IMHO, needs to be added to the software app:
- A “PPK Survey” page to remove confusion with all the RTK related pages. All PPK surveys would be started and stopped from this page.
- On this tab you you select from 3 types of surveys: static, kinematic and stop-and-go.
- The ability to enter a filename would be nice.
- For Stop-and-go a automatic file naming process is implemented that auto increments the file name for each point that is collected.
- For Stop-and-go a basic count down timer (user entered) for initial lock (initialization) and for point collection would be required. Also, having a warning box pop up if lock is lost. If lock is lost the user would then be told to re-initialize before collecting the next point.
- Having the ability to add a description to each file would be nice.
If the above is not possible it would be really useful if “lock” or whatever happens internally, is maintained while in static collect mode white the receiver is on. This would provide a viable work around for doing a stop-and-go survey with short collects. So when a user turns off raw logging lock would be maintained – until the unit is turned off.
I would love to know how those that are using a pair of Reach or Reach RS units (one for base and one for rover in PPK mode) are collecting multiple points. Are people sitting on each point for 10+ minutes? Am I missing something?
Oh, here’s an idea: I suppose I could use my TuffWing trigger cable connected to a Reach GPS and a camera and collect points by taking pictures! One could use an intervalometer, for example, to take one photo every second for 15 seconds while remaining stationary over a point. In post processing, in RTKPost using the TuffWing workflow, these camera event position are logged to a file: "name…events.pos. This file could then be imported in a spreadsheet and positions averaged. This would work – I think. Makes me wonder if a cheap intervalometer could be wired directly to a Reach GPS to avoid the need for a TuffWing cable and camera? However, I don’t know how one would do this with a Reach RS.
Anyways, sort of rambling here. In the end a simple Stop-and-go PPK addition to the software app would be extremely valuable. This would be very helpful for the UAV mapping community (those not doing RTK) that want to use Reach units for surveying ground targets. With this addition you then have a survey tool that is a nice alternative (in good conditions) to a $10,000 Trimble.
Just my 2 cents.
