I was working at our landfill today trying to resolve the elevations for their last lift to finish off a cell (height). Doing it with my trusty 4600LS (L1 Trimbles) from Hillside AZ (Phil knows this mark) and a few other points.

I experimented with the MM this past weekend and had less than stellar success with the post processing..Mostly to my 20 years of TM knowledge no doubt. lol You just gotta wipe the mind and start fresh sometimes...

Today when I got my other units running I took the manual with me and spent about 30 minutes reading the post-processing part.

Suddenly, it became clear...Duh!..

In another 10 minutes I was doing MM points for post processing on the same points that I was doing 30 minute L1 sessions.

When I got back to the office I downloaded and processed the project that I was working on and then dumped the main base file via rinex to my MM project file and downloaded the MM.

This time is worked perfect. I opened the job and it showed each point and the timeline at the bottom, along with the timeline of the rinex.

Had to back up once or twice to get the SPC NAD-83 to work in US Survey feet but it was just a toggle that I had missed.

I had four corners at the top of the landfill and I hit them as fast as I could..20 seconds of MM data on some shots and then I slowed down..(yes, certain ages tend to do that as a the day progress's in 100 degree heat).

This is not conclusive, and I haven't posted any results until I was sorta sure I was doing it correctly. (still not 100% sure, but 99% at this point)

Deltas..

NW Corner N 6' E 1.5' El 25'...(my first point and probably not near enough data..these had very short data sets)

NE Corner N 2.5' E 1.0' El 8' A bit better with 1 minute sessions.

SW Corner N 0.7 E 0.01 WOW! El 2'...Lots better with 2 minutes.

SE Corner N 0.1 E 0.5, El 2'... Three minutes elapsed..

Oh...And each of these deltas were the average of 4 seperate collections, but all held to the same amount of time.

Perfect sky, no obstructions.

JD..I lied, or actually wasn't doing it correctly. The MM does show the PDOP's while gathering data. Funny thing is that I saw 3.5 to 4.5 during the entire morning, but the processing software said I had 2.5 to 2.8.. So the field unit is pessimistic..That is good I suppose..

Now if Thales would call about the darned symbols in the base map then I would be happy. It's been a week and no response..

Boat anchors for Fire Hydrants look silly..

Such fun..

JD...I also took some longer readings on Paulk East and Paulk West (the ones by the pool)... I can't find my coordinates now, but I'll post those results later.

This is all going into a spreadsheet for others to view at some point. Just redneck data.

The thing I missed in the output to the CSV file was 'time on point'..I don't want to have to keep a file on this.

Deral

How long did you have the unit running before you started logging shots? This seems to make a difference in doing submeter work. Even with the real time units the results are much better if the unit has been running for 10 minutes or so before logging anything.

Also, can you do offsets for points in canopy? It sure would be a necessity for this part of the world. A simple az and distance would be ok by me.

The pdop difference in the field vs on the computer is also in the PM2 and Solutions processing. Solutions always reports a lower pdop than the PM2 does while collecting. Just like the mission planning always shows fewer sat's than what is actually available. I suppose pessimism is good to a point. But I would personally like to just see the right answer and decide for myself.

BTW, looks like some pretty good numbers. Keep us posted.

Are these the average of four different observations? How did each observation check against the 'knowns'?

I just fired it up each time...When the clock turned into a triangle, then I logged data.. The unit had computed a position.

Post processing doesn't depend so much on how long the unit has been running but if it is gathering positions.

I was pretty excited about today's results. Now that I sorta have a handle on it, then I plan several more really good tests on the post-processing..

CORS from 30 and then from 100 miles away. The results should be comparable.. It's only doing a simple time/move process.. No iono, no tropo, but just a simple differential processing.

I don't plan on having a base up for most of our GIS work. I will use the CORS for the rinex data. If our local is down, then I expect to use a remote location and get the same results.

Oh...I had no external antenna. Just the plain little blue beast handheld..

I moved it up and down a few times, so this was not a good test of vertical, and I don't really think anyone would look at sub-meter vertical anyway..

This weekend, not that I know how it actually works, then the MM will run some sessions on Paulk E and Paulk W...

Deral

I found no way to do offsets, other than by recording by hand. That is a small issue, but an issue..

Many infrastructure points, such as hydrants or manholes are in very poor GPS places.. An offset feature would be welcome...

Thales..If it's in the software, then I just haven't found it yet..

I just want some more symbols for the background map..

If we get a MM for our water department, then all I would load is our street map, water valves, water lines and fire hydrants...I need to have a symbol for each..

If we get a MM for our sewer department, then all I would load is our street map, SSMH's, Line segments and SSCO's.... I need a symbol for each.

And list goes on...

The MM is a very fine receiver and if they are marketing it to Public Works and GIS, then we need some more symbols, or the ability to create them ourselves.

Deral

PS-I love my MM ....Thinking about getting a bumper sticker made.

"PS-I love my MM ....Thinking about getting a bumper sticker made."


Yeah. I like Mike Margolis too, but if you keep talking like that he's gonna think something's up with you...

i see another movie in the makin'

director Dave needs to jump in

Deral

I still am real interested in the quality of results with an external antenna.

You said something about averaging multiple observations to get the posted results? Please expound on that.

I realize we don't absolutely need a real time submeter box to do GIS work, but we would like to know we have submeter capability (at least 1 sigma) for single observations when having to post process.

If you want to make a quickie road trip in the next few days, we can mix and match some antennaes and cables, as well as some local control for checks. You said something the other day about the antenna port on the MM being a small "pin type" connection and we discussed what type of "pin" it was. Could it be the same type of connection used with the ProMark2 antenna? Maybe Phil or Mike will know. Surely the external antenna connection is for a current Thales antenna product.

jd

If you start this then I'm going to suggest a movie about the "Screwing a locus on a Post"...Most likely a sure Stephen King movie...

Dave...Help me out..Come to the rescue...They are gangin up on me..
(and I promise no more pizza pan jokes)

Deral

You guys have the antennas..

We purchased the unit 'as delivered' to get sub-meter results, post-processed.

This is the unit that we will recommend to other divisions and other cities based on results of the 'out of the box' units...if it meets our expectations.

You might get killer results with another antenna, but that is not our goal...

We expect to rig up a fixed pole with the MM (no gender implied) and do sub-meter work with what we are supplied..

For you and me, then yes, we will push the cushion and try other things, but I'm thinking about the others that might be gathering information..

Deral

Worlds FASTEST Mobile Mapper

Act I

(in the distance, the roar of a big V8 is heard. Unlike the intro scene to "Le Mans", in which Steve McQueen is seen driving the hills in a Porsche 911S, this car we can't quite make out.

Moments later, the sound of tires screeching and a cloud of dust, a BIG cloud of dust appears....)

creeeeaaakkkk, BAM! as JD steps out of the Stumpwater Brewery and into the front yard.

JD: What the heck is THAT??

Sound of hydraulic lifts.....

psssssssssssssssssssssssssttttttttccccccchhhhhhhhhh

Deral: Hey JD!

JD: Deral! Whats up! Say, isn't that the NEW Ford GT you had ordered? Just like the original GT 40 that dominated the Ferraris in the 67-69 Le Mans??

Deral: Yep, tis the one. Say, I heard Dangerous Dave was headed back to California next month to see the Monterey Historic races......this years Marque is Ferrari!!

JD: Huh? He told me he was into the movie business!


Ahhh...forget it.

Dave

Some things I am learning about the MobileMapper:

The ProMark2 antenna works very well with the MobileMapper and provided results that surprised me. The antenna cable for the ProMark2 plugs into the side of the MobileMapper. I prefer using the MobileMapper with the ProMark2 antenna whether I am using post processing or not. But then everybody says I am an old lady.

I rigged up my RTK rover pole and bipod with a ProMark2 antenna and used an old Husky FS/2 bracket for the MobileMapper. A link to some photos is in the training folder.

I do not want to say how well it worked because I do not yet have enough experience to know that what I saw will repeat from day to day, week to week, and month to month.

The longer I was able to maintain a good solution as I moved between points the closer the positions seemed to converge on the truth. Part of it may be about the occupation time on a point. But right now I am thinking it might be more about how long it was since it last had to go to work on a solution.

What I am talking about is a little outside the box - maybe. It is not an advertising claim. I am just talking about another little science project. MobileMapper is not an alternative to the ProMark2 but I suspect it might be a way to map water valves.

For Deral that may seem contradictory to his method of working with GIS tools. But I am just remembering a short session working with Deral one day a bunch of years ago. Seems like we did not concern ourselves with keeping lock or maintaining a solution. The MobileMapper method is similar to the way Reliance works. If you and J.D. get together let him show you how to make Reliance hum and copy the method.

Deral, do you remember my bet about the Reliance accuracy that remains unchallenged? When I get the same amount of experience with the MobileMapper I may be ready for a new wager.

The request for more icons has been submitted as a feature request. I know only one person who has figured out how to customize the icons. When she asked me if anybody would pay for what she knew I told her not to tell me how she did it. Today she was asked to reveal her secret. Her answer was "persistance".

If you want something different in the .csv file send me a little example and I can pass it along as a feature request.

Phil,

Correct me if your experience is different, but when I tested a mobile mapper a few months ago it appeared the standard PM2 antenna connector was a little too large for the mcx antenna connector on the mobile mapper.

I did not want to force it so I used a custom cable assembled with a standard mcx connector at one end and the tnc connector for the promark antenna on the other.

It’s nice to have a solid setup for testing with the antenna over your head to eliminate at least that part of the multipath.

I was hoping for better integration of MM post processing data collection with the PM2 system , but as we now understand the MM is a GIS and real time data collection and viewing tool and not a survey grade receiver.

I will be on the lookout for early reports on the new MM-CE with bluetooth dgps and arcpad integration. Sounds like it has great potential.

you just brought up the very subject that Shawn and I were discussing about maintaining lock. Just like you taught us to make the Reliance perform, particularly when doing post-procesed sum-meter (or decimeter) work. Crank it up and let it run for 15-20 minutes before the session begins, then go collecting data. Thirty seconds to a minute is normally sufficient .... if you maintain lock. I think this all had to do with "backwards processing"?? Does the MM software work similar to the Reliance Processor?? Would the extended run time, avoiding loss of lock, improve the results? (I bet it would, but I ain't the gambling type)

jd


ps will the PM2 antenna cable plug actually fit the connector in the MM?

Modified By J.D. Billings on 7/22/2004 at 12:45 AM

Well, guys, I keep saying it. I frequently use a ProMark2 antenna and a ProMark2 antenna cable with the MobileMapper. Not always.

You do not have to believe what I tell you. Go to the ftp server, click your way to the training folder, download the MobileMapper science project file. Go to the link to the photos Sharon took of yours truly and the MobileMapper rover pole setup I have described. You will also see some of my map tinkering. You will find one image of Sharon and me driving down from the top of a three level parking lot with the MobileMapper on the dash. I was tickled about that when John was asking his questions about GPS in a parking garage but avoided making unbelieveable claims. Yes, it did get lost. But I expected no more than the first circle around the top of the garage to even show up on the map.

L.A. was right about one thing. MobileMapper files are not intended for use in Ashtech Solutions. However, the ProMark2 makes a great base station for the MobileMapper post process data.

If I was getting ready to start my new low-budget surveying and mapping company today my toolkit would include a ProMark2 system and a MobileMapper. For less money than my robot total station I would be in the geodetic survey and GIS data capture business.

J.D. and I share a concept about how the Reliance software works and that is my comprehension of the MobileMapper software as well. I am not a software wizard. Like you, I am skeptical of claims, so I go outside and experiment. I ask questions of the people who are in charge of the tools and then I test the theory against my dirt surveyor concepts about how it might work.

Most of my science projects posted were done with older versions of the tools. Recent months have had me doing science projects of a different kind. Some of the rewards of that effort are already on the ftp server and some will be soon.

One day soon I am going to get more serious about some MobileMapper things and will try to have more things for you to look at. But you may not trust that more than what is already there. That does not bother me. Having spent 17 years signing the front of business checks I understand healthy skepticism.

You guys don't ever have to believe anything I tell you. The proof is in the dirt.

If you still do not believe the photos then my next suggestion is to call your Thales Navigation dealer and ask for an opportunity to feel it in your hands and see it with your eyes. What you do with it matters a whole lot more than what I do with it.

The time elapsed for logging on each point is what I would like to see in the CSV file.

It may be in there, that I have to toggle, I'm looking into it now. Maybe another toggle.

While testing, I may use the same point 20 times, using different times on the point. I would like to see the amount of time in the spreadsheet without writing in a field book.

The CSV shows the start time, but not the elapsded time. Once we figure out how much time is actually necessary (for my piece of mind), then it will not be necessary to worry about in the field during actual GIS survey's, but for the testing period, then it's handy.

Interesting about the time running..I'll check into that. Actually when I looked at my results again, the later points were the best. I did four sessions on each point without turning off the receiver. I only turned it off between the four corners except now that I think about it, I did not turn it off from the last two points, which had the best results. Hmmm..

I'll have to experiment a bit with that.

Deral

Keep it running and looking at the sky as you move between points. Carry a sandwich bag with extra batteries in your pocket to make it through a day of field work. Even if you are driving between points keep it turned on.

You already know that you don't HAVE to keep it on. It's just a little more science.

I have been successfully experimenting with the rechargeable batteries that Robert Snow found. Do a search for posts by Robert Snow and you will find the information. I used the batteries for two weeks while mapping a long road trip.

Could someone email me a MM file set so I could take a look at it? I'm a little out of the loop and have had a lot of questions thrown my way lately..use bobbills@toast.net...thanks...b

PS...zip files are good....
Modified By Robert Bills on 7/22/2004 at 8:53 AM