#001-Deliver your point cloud directly from the field!đź’Ş

Lukasz Wiszniewski
7 min readMay 31, 2021

Is it even possible?

Fot. Trimble X7 — outdoor acquisition

Have you ever wondered how to be more efficient with laser scanning delivery? Trimble is coming with the simple answer — constrain, export and deliver the data directly from the field. Is it a really efficient and good solution? How does it work? And is it worth it? You will get answers to these questions and my subjective rate about Trimble X7.

Technical specification

Tab. Technical specification

First impression

Trimble X7 gives the feeling of a solid, high-end device. It looks differently comparing to its competitors like Leica RTC360, Faro S series, or Z+F Imager 5016. The spinning mirror is covered by a cylindrical element/tube with a glassy/shiny stripe and 3x coaxial 10MP cameras next to it. Under the heart of the scanner is placed an element that looks like UFO with many lights around. It is not a rotatable leveler of the scanner’s body which can automatically level X7 in the range of 10deg.

Fot. Trimble X7 in the backpack

The whole scanner weight is equal to 6,15kg (with the battery) so it is placing in between RTC360 (6,1kg including 2 batteries) and Z+F 5016 (approx. 7.5kg including 2 batteries). I got it in a comfy backpack which helps a lot to carry the entire set. X7’s body has a big handle which helps to place it on the tripod. In case you do the acquisition in difficult conditions and tight places it helps to safely take the scanner off and transport it in your hand between scan stations. I found out it very helpful.

I really like the lightweight carbon tripod which is stable and easy to use. It is quite similar to Leica’s RTC360 tripod but noticeable higher which makes it really comfortable to use on height over 1.8m. It is useful in many hard-to-reach spots.

Fot. Trimble T10 tablet. Notice the registration fail even though 19% overlap.

Together with Trimble X7, a user gets tablet Trimble T10 tablet with preinstalled Windows 10 and Trimble Perspective software. Tablet is very robust, waterproof with IP-65, and heavy-duty but also quite heavy. On the one hand, robustness like this is desired when you work in difficult conditions like the construction site or factory. On the other hand, it is uncomfortable to use in long term. Even with the arm-stripes, the user feels the weight on the arms and back very quickly. I had the only over-arm type of stripe, so perhaps some harness-type stripes could be much nicer to use with the tablet.

First things first. I divide this review into two parts: fieldwork and processing of the data.

Fieldwork

The user doesn’t need any long introduction training to begin work with the X7. Do not understand it, my dear reader, that is simple equipment which can be used by anyone. It is a powerful scanner with many advanced features but at the same time quite easy to use for less advanced operators. Most of the features and options are intuitive. I lost myself in the very beginning but I believe it is because I am not used to so many options.

The scanner connects with the tablet via WiFi and there is no trouble pairing them. The user can start scanning in a few moments. When the Trimble Perspective is up and running and X7 mounted on the tripod, you have to choose the resolution of the scan from four available options: 2, 4, 7, and 15 minutes, sensitivity, either take a pano-images or not with or without HDR, and white balance preset. During the entire scanning process, you are informed by notifications about happened actions like scan is over or created connection between scan stations. This is a really useful feature and helps to not get confused among software’s options.

Tab. scanning parameters — trimble.com

Since the user hit button — Start Scan — the scanner begins some “dancing” which is the calibration and auto-leveling process. The first dance is always the longest and is shorten in the next scan stations. Trimble X7 has implemented one more cool feature! The build-in compensator indicates by 3 LEDs respectively to each leg of a tripod, when the scanner is out of auto-level’s range. It is easy then to quickly change the position or the height of this particular leg which of course has to be done before starting scanning. When it is calibrated and leveled, the magic begins.

I was very surprised when the acquisition began because it was silent! Wow! My experience with other brands is different. Every scanner I used until I tried X7 was loud or very loud like RTC360. That is a pleasant feeling when the equipment you daily work with is silent and does not bother people in the nearest zone. I see it is very useful in projects where you have to scan offices during working hours and you don’t bother people around you.

Trimble X7 is fast but not as fast as I expected and as Trimble claims. I found out that a single scan station in medium resolution and standard scan mode takes mostly about 4min 52sec. It includes auto-calibration, self-leveling, scanning, and taking pictures. Datasheet informs about 3:30 of scanning time and taking pictures for mentioned settings which is almost 1min and 20sec shorter. Reality is different! You perhaps wonder about weather conditions and scanned environment. I believe that a picture was taken that day present it the best. There are no reasons why the scanning time is longer than the estimated shown on the tablet’s screen.

The self-leveling feature works great. It takes from 26 to 50sec including auto-calibration. I didn’t find any pattern why the time is not even every time. Time was measured from the moment I hit a button — start scan, until the scanner began rotating.

In few seconds the point cloud is downloaded from the scanner to the tablet and it is ready to inspect. Trimble Perspective software has plenty of options to visualize and manipulate the point clouds. I am not going to describe all of them but believe me, the software is complex as a regular desktop application dedicated to laser scanning data.

Every newly downloaded point cloud from the X7 can be auto-registered with another point cloud in the same project. Users can choose which scan to register to. If for some reason the auto-registration would not succeed then it is possible to do it manually.

When the data collecting is over, a user has a chance to register all of the point clouds, create connections among scan stations and export the entire project to Trimble’s file formats or formats like e57, PTX, or LAS. Trimble T10 is a Windows tablet that makes simple the next step of workflow which is delivery. As Trimble advertises, with X7 everyone can deliver the final data to the customer directly from the field. It is easy to use some cloud solution to upload files and send an email with the link to it.

Unfortunately, the registration process is not as robust as it is advertised. There is a limitation in the number of links among scans which doesn’t help to create a strong network of connections. That means you are not sure does the final point cloud is accurate. Outdoor scanning challenges registration features to their limits. I occurred situation where the overlap was good but I couldn’t link those two scans. Then the solution is to do an extra scan between those two. In the case of a project with over 150 scans and the necessity of an extra scan for each 10th scanner position, the project’s price will increase by about 1,5 hours.

Battery

A quick summary about batteries. They contain led indicators of capacity level which helps to recognize the proper time for charging. Acquisitions were done in very good weather conditions. It was a sunny day with approx. 17 C deg. Battery capacity suppose to last for four hours according to the datasheet. My experience says 2.5h takes to use a battery from 100% to 25%. After 3h you can see 15% of the remaining battery power.

Fieldwork summary

To conclude, Trimble X7 is a very good and robust product. It has some advantages and disadvantages among HDS (High Definition Surveying) devices which are described below. I like the housing of the scanner, silence during acquisition, and advanced possibilities given by Trimble Perspective. I disagree that the constrained data quality is good enough to deliver it for a customer directly from the field. I noticed, many producers of TLS equipment describe their equipment as simple to use as plug&play, which is not!

Props:

  • Notifications about actions
  • LED indicators in the compensator
  • Auto-registration of two scans
  • Manual registration possibility
  • Handle
  • It is silent

Cons:

  • Registration fails even though the good overlap between scans
  • An only a single connection between neighbor scan stations — impossible to add several connections to make a dense net of them
  • Poor screen brightness of the Trimble T10
  • Data properties don’t update automatically information about registration (registered/not registered)
  • I missed remained scanning time counter
  • Missed seamless data transfer between the tablet and RealWorks/TBC — it is required export to TDX file format
  • Automatic abortion of a manual registration while new scan begins
  • Trimble T10 gets to be unpleasant hot after a while

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Lukasz Wiszniewski

I am a geomatician and software developer with over decade experience in reality capturing and BIM. More info read on 3d-points.com