Tripod Data Systems Survey Pro for Pocket PC

TDS Survey Pro for Pocket PC is designed to operate on the iPAQ Pocket PC. In the May 2002 issue of POB, I looked at the iPAQ hardware and discussed some of its advantages and limitations compared to traditional ruggedized data collectors. In this installment, I will focus on the Survey Pro software.

The software was tested on an iPAQ 3650 (Compaq/HP, Houston, Texas) and on the new 3850, which is quite similar to the 3650 but has more memory (64 Mb RAM) and a 1400 mAh hour battery. Compaq has recently introduced a Compact Flash Card Expansion pack that incorporates a removable and rechargeable 920 mAh battery. Although I did not have the opportunity to test the new expansion pack, it seems that the ability to change batteries in the field would minimize or even eliminate the iPAQ’s limited battery life. The 3850 also has a more robust serial connector than the 3650, although it is still somewhat delicate compared to connectors commonly found on ruggedized data collectors, so some external means of supporting the connector is still required. TDS supplies a support bracket for this purpose. The instrument used for this evaluation was a Trimble 5600 Robotic Total Station (Trimble, Sunnyvale, Calif.).

Getting Started

The upper half of the startup screen of Survey Pro is divided into program categories; the lower half displays functions available in the selected category. For example, picking “File” presents you with a list of file functions for opening files, creating new files, saving files, etc. The screen on the iPAQ is touch-sensitive so selections are made using a stylus.

When using the software for the first time or when changing instruments, a user would pick the “Job” button then select “Settings.” The instrument brand and model may then be selected. The “Settings” window allows instrument communications parameters to be selected. Default communication settings are built into the program for many instruments, but the settings can also be customized. For example, the settings for the Trimble 5600 with Direct Reflex measurement allow the user to select the EDM measurement mode, whether to use a prism or use the Direct Reflex measurement. Once the settings have been configured they are saved and recalled the next time the program is run.

Survey Data Collection

For data collection, the “Survey” tab is the one most often used. Under the “Survey” tab, the “Backsight Setup” choice presents you with a screen where you can enter the occupied point and backsight point. You can use the iPAQ software input panel (SIP) to directly enter an alphanumeric point name in the text box. Or you can bring up a complete list of points to choose from. You can also pick the point directly from the map view. In cases where there are a number of closely spaced points, picking a point with the stylus brings up a listing of nearby points for you to choose from.

After the occupied point and backsight have been input, the user picks the “Solve” button, which brings up the map screen to graphically show the setup information. After toggling back to the “Input” screen the user can use the “Circle” button to zero the instrument on the backsight (or set any other angle on the backsight). The “Check” button can be used to check the backsight by either angle or distance.

I found that when the Trimble 5600 was set to autolock and the backsight prism sighted, the backsight setup routine caused the instrument to move up or down off the prism, thereby losing lock. This required manually moving the telescope back to the prism so that the distance to the backsight could be measured. I understand from TDS that this is caused by not having the correct instrument and backsight prism elevations recorded in the coordinate file. As I do two-dimensional surveying almost exclusively, the elevations recorded in the coordinate file are arbitrary. The program is designed so that in robotic mode you are able to remotely check or reset zero on the backsight. I understand from TDS that the Survey Pro software is not commonly used for collecting data in cases where instrument and target heights are not recorded, so this feature would not present a problem for the majority of users.

(Editor’s Note: According to TDS, an active prism is needed on the backsight because the Trimble 5600 does not lock onto the glass of the prism (or any other shiny object), but to the signal from the active prism. For other robots that lock onto the glass of the prism, this is not an issue.)

After setting the backsight, the user selects “Traverse/Side Shot” from the “Survey” menu. If you have forgotten to check the backsight the software will prompt you to do so. Survey Pro software allows you to have Description Files with and without feature codes, which can save the user considerable time by not having to type lengthy descriptions. The description file is simply a text file you created on a computer that contains the most commonly used point descriptions. As you begin to type a new point description, the Description text box opens into a drop down list box where you can scroll up or down to select an existing point name. This technique permits very fast and efficient entry of point descriptions.

Once the correct point description has been entered, picking “Side Shot” or “Traverse” causes the instrument to make a measurement. The button highlighted in red (“Side Shot”) is the default button assigned to the big silver iPAQ enter key so you could also take a side shot by pressing the enter key. Using the “Settings” option the user can select whether to be prompted to input a point description after each shot or whether to use the existing description without being prompted. If many shots are to be taken with identical descriptions, it is quite a bit faster if the user is not prompted. The shot is stored automatically after it is taken.

Choosing “Side Shot” increments the foresight point number leaving the backsight and occupied points as they were prior to the shot. Choosing “Traverse” changes the occupied point number to the foresight number (that was just shot) and changes the backsight to the existing occupied point. When traversing, the user is given the option of traversing immediately or of continuing to take side shots and traversing later. Some surveyors may prefer to take the traverse shot as the first shot of a new setup, while the setup is “fresh.” Using “Traverse Later,” side shots can be taken after the traverse shot without the need to reset the occupied and backsight point numbers.

Survey Pro includes a number of routines for locating points that cannot be seen or measured to directly from the instrument. These routines include Distance Offset, Horizontal Angle Offset and Vertical Angle Offset. There are also routines designed specifically for reflectorless total stations. A routine called “Corner & 2 Lines” is used when you want to locate a building corner. Two shots are taken on each face of adjacent building faces. The software then calculates the corner by intersecting the lines on which the shots were taken. There are several other routines that cover other situations; these functions have the ability to overcome the difficulty some reflectorless total stations may have in receiving a return signal from the sharp corner of a building or other object.

The stakeout routine is very powerful. When stakeout is selected, the user is presented with a screen that allows the “Design Point” (the point to be staked) to be entered. The Stake Points screen shows the name and description of the point to be staked along with the angles and distance from the instrument. A small window also graphically shows the relationship between the points. The point to be set is the small red and white target. When the “Stake” button is picked a new screen appears that allows the instrument person to take a shot. In the example, the rod person needs to move back 5.18 feet and left (facing the instrument) 5.04 feet. If the instrument is robotic, a graphic screen showing the relationship between the rod, and the point to be staked is continuously updated. By watching the screen, the rod person can literally walk to the point. Once the point has been set, its actual location can then be stored in the coordinate file. The user will then have a record of both the desired location of the point and the actual location where the point was set, as well as optional cut sheet data stored in the raw data file.

In boundary surveying, it is often useful to be able to set intermediate points along a property line. The “Stake to Line” routine can be used to set points on the property line. Any two points on the line can be used to define the line. The rod person walks to a position, hopefully somewhere near the line, and the “Shot” button is selected. The results show the distance, measured from the rod, “Back” or “Forward” along the line from the instrument to the property line, which would intersect with the property line. An offset distance perpendicular to the property line is also shown. In the example, the line to be staked (shown in green) is nearly 90 degrees to the line from the instrument to the rod, so both distances are identical. In such cases the offset distance would be most useful. A graphic display showing which way to move to be on the line makes staking to a line very easy and intuitive.

In addition to the above described staking routines, Survey Pro also includes Offset Staking, Slope Staking, Curve Staking and Spiral Curve Staking, a complete Roads Menu and Coordinate Geometry functions. You can also adjust a traverse and even make solar observations. In fact, TDS Survey Pro is such a comprehensive program it is difficult to think of a survey routine it doesn’t have.

Tripod Data Systems
P.O. Box 947
Corvallis, OR 97339
541/753-9322
www.tdsway.com

Suggested List Price:
Complete package starts at $995 and includes Survey Pro for Pocket PC card, cables, iPAQ support tray and soft environmental case. Package does not include iPAQ.