Procedures for Control-Point Mapping

Modification to Short Instructions for SDR33 Setup

The instructions for setting up a SDR33 are given here. For control-point mapping we use the following settings under "Configure Reading"

Configure Reading

• Type: Total Stn
• Auto pt num: The number displayed here is the next automatic point number that will be used. For control-point mapping it is usually set to 2. Point 1 will be your first instrument point.
• Topo view stored: Set to "OBS". This stores the observations - horizontal angle, vertical angle, and slope distance.
• Combine F1/F2: Generally set to "No". If it is set to yes, the SDR33 will force you to take a F1 reading, then a F2 reading. It will then average the values and inform you if the difference between reading is greater than any tolerances you have set.
• # dist rdgs: Generally leave as "1". This is the number of distance reading the instrument will take. If greater than one, the distances are averaged. If you are only measuring angles then you can set this value to 0. This disables the EDM for normal readings.
• Tracking: Generally "No". If set to "Yes" then the EDM constantly takes measurements.
• Code list active: Generally "No", unless you have developed a code list.
• Info blocks: Set to "0". This is the number of comment block associated with each reading.
• Code fields: Set to "0".
• Recip Calc: Set to "Prompted"

Procedure for 'shooting-in' points

Case I. Starting a new map

If you are starting a new job this is the time to set up your coordinate system. If you are making a control-point map then you will want to orient "North" along the long axis of your mapping project. Point the total station along the long axis and use the instrument control panel to set the direction to zero (see instructions below). Then, when the SDR33 prompts you for the instrument station number, enter any number (usually 1). When prompted for a backsight reading, just press OK, and then confirm that you want to skip the backsight. The SDR will not reset the instrument under these conditions.

• At this point you should have the Total Station setup over your first point, and the SDR33 should be configured.
• Set the zero direction in the Total Station. Do this by pointing the total station along the long axis of the intended map. Press the ENT and then 0 SET keys on the instrument,
• Start by pressing 'Clear' until you have the main SOKKIA screen
• Press Clear one more time
• At this point you should see a screen with space for a job name, station, and backsight.
• Select SURV (F2 key)
• Select Topography and press the OK key
• At this point, if you will enter the Job Creation screen.
• Select the appropriate job parameters and press OK. Press OK to pass the screen that allows you to type a descriptive paragraph
• You will now enter a screen asking you for
  • Stn: Enter 1, since this is your first station (press enter)
  • North: For the first station I usually use 0 (press enter)
  • East: For the first station I usually use 0 (press enter)
  • Elev: For the first station I usually use 100 (press enter)
  • Theo Ht: (press enter)
  • Cd: This field allows you to type a text identifier. (press enter)
  • Press OK when done
• You will now enter a screen asking you to confirm the backsight
• Press OK
• Press F1 to confirm that you are not entering a backsight
• You are now ready to start taking readings.

• To take a reading, align the crosshairs on the target, and press the large blue key in the bottom right corner of the SDR33. This will take a reading and display the angles and coordinates on the screen. You can move about this screen with the cursor arrows.
• Enter some text. For most points I just use the text "Point"
• Enter the reflector height.
• Press OK to save the data.
• The SDR33 will remember both the point name and reflector height from now on, although you can change them at any time.

Case II. Continuing an existing map

If you are continuing a job where it is important to orient the instrument, you should set up the instrument over a known point, and set up a reflector over a second known point. When starting to use the SDR33 specify the station number where the instrument is located. If the point number exists in the current job, then the SDR will display the stations coordinates and ask you for a instrument height. If the point number is not found in the current job then you will need to enter the coordinates of the current instrument station and the instrument height.

After specifying the location of the instrument you have to indicate the backsight point number. Again, if this point exists in the current job, you will asked to point the instrument at a target over this point and take a reading. If the point does not exist, you are given the choice of either entering the coordinates of the backsight point, or the direction to that point. Once you have entered the information about this point, then you will be asked to take a reading to this point

The SDR will set the horizontal circle to value you entered, or from it’s record of point. It will then take a reading to the point and verify that the range and elevation difference match what is has in the job database (if it is a pre-existing point).

At this point you should have the Total Station setup over your first point, and the SDR33 should be configured.

• When you start the SDR33 it will take you to a screen displaying Job, Stn, and BS point. These should have been the last points you occupied.
• Press the F2 (SURV) key
• Select Topography
• Enter the point number you are occupying
• You will enter the Point coordinate definition screen. Check these values, and change the descriptive text if needed. Press OK
• You will now be asked for a backsight point. Enter the BS point number and press OK
• Align the crosshairs on the target at the backsight point and take a reading. The SDR33 will set the correct orientation in the instrument
• Proceed as normal to get more points. They will be in the same coordinate system as previously surveyed points.