Advanced Network & Services Surveyor FAQs

I. Hardware FAQs

The information in this FAQ is provided for the sole purpose of supporting Installation and maintenance of the Surveyor Measurement machine for participating members. This information should not be duplicated or distributed without the permission of Advanced Network & Services.

See Advanced Network & Services for additional information on the company and main office contacts.

Finally, this FAQ is under constant revision, please check back frequently for updates and changes.

II. GPS Questions

Q1: What are the dimensions of the Antenna?

The GPS Antenna is available in two different sizes based on the length of cable from the Surveyor machine to the roof or mounting point of the Antenna. For cable runs under 200 feet, antenna specifications are:

Model: 142-400
Size: 2.625 inches in diameter by 1.5
Weight: Approximately 1lb. (.318KG)
Operating Temp: -40 to +70C
Power: 25ma @5v (supplied by unit)

For cable runs 200 feet and longer, antenna's specifications are:

Model: 142-603
Size: 4.4 inches in diameter by 2.1
Weight: Approximately .60lb. (.318KG)
Operating Temp: -40 to +70C
Power: 80ma @12v (supplied by unit)

Q2: How is the Antenna mounted?

Mast top mounting is the preferred mounting method. The antenna mounting mast should be 2-inch threaded water pipe or conduit. The pipe must be rigid and able to withstand high winds without flexing. Guy wires may be used to stabilize a pipe longer than 10 feet. Please refer to the section on GPS Installation for further detail.

Q3: Does the Antenna require power?

The Antenna receives its power from the GPS Card installed in the PC. It is therefore paramount that the cable connecting the PC to the Antenna be properly connected at both ends.

Q4: Will the Antenna interfere with other receivers / transmitters in its vicinity?

No. The GPS equipment is a receiver only, and will not transmit on any frequency.

Q5: What frequency / signal range does the Antenna operate at?

The following is the detailed input specifications for the GPS receiver:

Receiver Input: Frequency 1575.42 MHZ (L1)
Code: Coarse Acquisition (C/A)
Tracking: 6 satellites (4 for solution)
Phase Accuracy: < 2 microseconds to UTC
Phase Correction: Step size 100 ns after lock
Position Accuracy: 25 meters

Q6: What, if any, voltage does the Antenna receive?

Model 142-400 as described in question 1) receives approximately 5vdc from the Surveyor, and Model 142-603 receives approximately 12vdc from the PC as well. 

Q7: Does the Antenna have any lightning suppression capability?

No. A separate lightning suppressor is available and can be connected into the cable run and grounded. If this is a concern please contact surveyor-admin@advanced.org to obtain further information on installing this equipment.

Q8: Does the Antenna need to be grounded?

No specific grounding for the Antenna is required. If the cable is properly connected end-to-end there should be little problem of a short or surge affecting its operation. In the case that the location/area where it is mounted is exposed to severe weather conditions, a surge/lightning suppressor can be installed. (Please reference question number 7)

Q9: Can I use the signal from the Antenna for other services at my site like NTP?

Yes, NTP can be configured for use at your site via the Surveyor machine. Refer to NTP Server for instructions on having this service installed. For other services that may or may not be available or configurable on the Surveyor, please contact surveyor-help@advanced.org to discuss this further.

Q10: Can I use my own Antenna?

It is highly recommended that you use the Antenna provided with the Surveyor equipment for ease of installation and software compatibility. Before shipping, each Surveyor machine is tested with the corresponding type of GPS receiver and verified to be working properly. Of course there are circumstances when it is technically efficient to use existing equipment at the proposed installation site. If this is the case, please contact us at surveyor-admin@advanced.org to discuss this further.

Q11: Does the Antenna require any maintenance?

No maintenance is required after the Antenna is properly installed. It is always advisable to keep the general area clear of debris which could damage or reposition the receiver. 

Q12: Can I share / split the signal the GPS sends to the Surveyor for other uses?

Based on the fact that highly accurate measurements are being taken and recorded from this equipment, the Antenna should not be mechanically used for any other purpose outside of the Surveyor project. 

Q13: What type of cable connector does the Antenna use?

A TNC (Threaded) connector is used at the Antenna's cable end and a BNC connector at the receiver cable end. These connectors are provided by us, and are also easily purchased, if needed, at many computer shops and cable manufacturers.

Q14: How do I know if I properly installed the Antenna and Cable?

Please check the GPS Installation Section for detailed instructions on how to verify proper installation and GPS Signal reception.

III. Surveyor Questions

Q15: What is the Surveyor machine?

The current Surveyor measurement machine is a 400MHZ Dell GX1 PC running BSDI UNIX with the following hardware configuration:

Hard drive: 4.3GB, RAM: 128MB
Slot configuration: 1 PCI, 1 ISA 1 PCI/ISA ports
- 1 3.5" diskette bay
- 1 5.25" CD
- 1-1" x 3.4" hard drive bay
- 145W power supply

For further details on this equipment's specifications please visit the OEM's site directly. 

Q16: What are its dimensions?

The Surveyor Machine is a low-profile model which measures H:4.3" W 16.1" D:17.2".

Q17: Is a monitor or keyboard used or required?

A monitor or keyboard is not required after installation and the  Surveyor not shipped with either. A keyboard and monitor may be useful if troubleshooting during installation is necessary.

Q18: What are the Surveyor's power requirements?

For US power requirements, standard 120VAC @ 60HZ. For international deployments, the machine is configured for 240 @ 50HZ. Please contact surveyor-admin@advanced.org should your power requirements differ from the above.

Q19: Can the Surveyor machine be rackmounted?

Rackmount brackets are not available with the PC that the Surveyor machine is based upon, but the PC can be placed atop a shelf in a 19-inch rack.

Q20: What network interface (NIC) types are supported?

10/100BaseT, FDDI, ATM(testing)


Typically,  Surveyor uses 100BaseT Ethernet. However, in some cases other interfaces may be needed to place the Surveyor on or close to the DMZ. You can specify the NIC type in the Surveyor questionnaire that will be sent you as part of the deployment process

Q21: Where is the Antenna cable terminated on the back of the Surveyor?

The center BNC connector labeled "Antenna" should be used for the coax cable from the actual Antenna.

IV. Surveyor Network Placement Questions

Q22: Where should we put the Surveyor in our network?

Please reference the section entitled Surveyor Placement for a detailed description of this.

Q23: Are there alternative locations we can use?

The measurement machine should be on a LAN segment as close to the DMZ router as possible. The measurement machines are intended to measure the wide area network characteristics between sites. We would like to avoid skewing the measurements because of campus LAN traffic. In cases where it is impractical to locate the Surveyor on the DMZ, we suggest an uncongested, high-speed LAN segment one-hop from the DMZ.

V. Dial-in (POTS) Line Questions

Q24: Why do we need to connect a dial-in line to the Surveyor?

This provides us a means to remotely trouble-shoot Surveyor problems when the network is unavailable, as well as, avoid burdening your staff or resources unnecessarily.

Q25: Where does the Dial-in line connect to?

On the back of the Surveyor there are two RJ-11 jacks labeled "Phone" and "Line", please connect the POTS line to the "Line" side of the modem. Should the dial-in number change or there be a need to use a different number for access, please inform surveyor-admin@advanced.org with this new information.

VI. Site Contact Responsibilities Questions

Q26: How do I maintain this equipment?

The Surveyor is remotely managed by Advanced's engineers. Site contact assistance is only needed occasionally to troubleshoot or upgrade equipment.

Q27: What are my responsibilities after installing the Surveyor?

Site contacts are encouraged to actively participate in the project by critiquing the tools being developed by the Surveyor project. Some initial tools are at http://ippm-db.advanced.org/plots. Site contacts can also participate in the Surveyor mailing list.

VII. Troubleshooting / Help Questions

Q28: Who do I contact if I have further questions or concerns?

surveyor-admin@advanced.org

IIX. REFERENCES

Truetime, Inc 2835 duke Court Santa Rosa Ca 95407
Model 560-5500 GPS-PC, 560-5503 PC-SG 2, Model 560-5500-1 (Down-Converter) reference manual and technical documentation provided with Surveyor and Antenna.

Surveyor Project and IPPM Measurement Program contact:
Advanced Network & Services, Inc.
200 Business Park Drive
Suite 307
Armonk, NY 10573
(914) 765-1100 (U.S.)
(914) 273-1809 (Fax)

To subscribe to the IPPM Mailing List, contact:surveyor-admin@advanced.org

IX. CONTRIBUTORS

The following people contributed suggestions or material for this FAQ: