GAMMA Remote Sensing AG GPRI-II User manual

GAMMA Portable Radar Interferometer II (GPRI-II)
User Manual
16-Nov-2011
GAMMA Remote Sensing AG
Worbstrasse 225
CH-3073 Güm igen
Switzer and
www.gamma-rs.ch

Copyright 2011, GAMMA Remote Sensing AG. A rights reserved. This document contains
proprietary information that is protected by copyright. No part of this document may be reproduced,
transmitted, transcribed, stored in a retrieva system, or trans ated into any anguage in any form by any
means without the written express of GAMMA Remote Sensing AG.
The authors and GAMMA Remote Sensing AG have used their best efforts in preparing this manua .
However, the author and GAMMA Remote Sensing AG make no warranties of any kind, expressed or
imp ied, with regard to the informationa content, documentation, or fi es contained in this manua , and
sha not be iab e for technica or editoria errors or omissions contained herein. In no event sha the
author or pub isher be responsib e or iab e for any incidenta or consequentia damages resu ting from
the furnishing, performance, or use of this materia .
TRADEMARKS Products mentioned herein may be trademarks/or registered trademarks of their
respective owners.

Table of Contents
1. Read First...............................................................................................................................................5
1.1 EMC Notice.....................................................................................................................................5
1.2 Safety Guide ines............................................................................................................................5
1.3 Operating Safety..............................................................................................................................5
1.4 Manua Out ine................................................................................................................................6
2. Background............................................................................................................................................7
3. Quick Introduction.................................................................................................................................8
3.1 Instrument Setup..............................................................................................................................8
3.1.1 Leica heavy-duty tripod...........................................................................................................8
3.1.2 Motor with eve er and tower..................................................................................................9
3.1.3 RF Unit..................................................................................................................................11
3.1.4 Antenna..................................................................................................................................12
3.1.5 Instrument Contro er and Power Unit..................................................................................12
3.2 Operating the Instrument...............................................................................................................13
3.2.1 Operating the instrument through SSH..................................................................................13
3.2.2 Operating the instrument through HTTPS ............................................................................16
4. Detai ed Instrument Description..........................................................................................................21
4.1 Instrument Components / Package List.........................................................................................21
4.2 Instrument Hardware.....................................................................................................................22
4.2.1 GPRI-II E ectronics...............................................................................................................23
Chirp Generator.........................................................................................................................23
4.2.2 Antenna..................................................................................................................................25
4.2.3 Mechanics..............................................................................................................................26
GPRI-II Antenna Tower.............................................................................................................26
Tripod, Positioner and Tribrach Leve er....................................................................................26
Azimutha Scanner.....................................................................................................................27
Radio Frequency Assemb y (RFA)............................................................................................28
Contro er and Power Unit.........................................................................................................29
4.3 Instrument Software......................................................................................................................30
5. User Interface.......................................................................................................................................31
5.1 Loca Access..................................................................................................................................31
5.2 Graphica User Interface...............................................................................................................31
5.3 Termina Access.............................................................................................................................31
6. Software Reference..............................................................................................................................32
6.1 Acquire data...................................................................................................................................32
6.1.1 gpri2_capture_utc.py ............................................................................................................32
6.1.2 gpri2_capture.py ...................................................................................................................33
6.2 Qua ity contro fie d ana ysis of data............................................................................................34
6.2.1 gpri2_p ot.py .........................................................................................................................34
6.2.2 gpri2_raw_p ot.py..................................................................................................................35
6.2.3 gpri2_proc.py.........................................................................................................................36
6.2.4 gpri2_proc_a .p ...................................................................................................................38
6.2.5 mu ti_ ook..............................................................................................................................39
6.2.6 create_offset...........................................................................................................................39
6.2.7 SLC_intf................................................................................................................................40
6.2.8 rasmph_pwr...........................................................................................................................40

6.2.9 raspwr....................................................................................................................................41
6.2.10 mk_tab.................................................................................................................................41
6.3 Postprocess data............................................................................................................................42
6.3.1 SLC_stack.py ........................................................................................................................42
6.3.2 ts_p ot_cpx.py........................................................................................................................42
6.3.3 ts_p ot_diff.py........................................................................................................................43
6.4 Move the instrument......................................................................................................................43
6.4.1 get_pos.py..............................................................................................................................43
6.4.2 home_run.py..........................................................................................................................43
6.4.3 move_abs.py..........................................................................................................................44
6.4.4 move_re .py...........................................................................................................................44
6.4.5 stop_scan.py...........................................................................................................................44
6.5 Maintenance..................................................................................................................................44
6.5.1 chupa_status.py......................................................................................................................44
6.5.2 chupa_test.py.........................................................................................................................44
6.5.3 ff_init.py................................................................................................................................44
6.5.4 gps_poweron.py.....................................................................................................................44
6.5.5 gps_poweroff.py....................................................................................................................44
6.5.6 ima_poweron.py....................................................................................................................45
6.5.7 ima_poweroff.py....................................................................................................................45
6.5.8 rfa_poweron.py......................................................................................................................45
6.5.9 rfa_poweroff.py.....................................................................................................................45
6.5.10 rx_poweron.py.....................................................................................................................45
6.5.11 rx_poweroff.py....................................................................................................................45
6.5.12 tscc_status.py.......................................................................................................................45
6.5.13 tx_poweron.py.....................................................................................................................45
6.5.14 tx_poweroff.py.....................................................................................................................45
6.5.15 usrp_poweron.py.................................................................................................................45
6.5.16 usrp_poweroff.py.................................................................................................................45
6.6 Fi e Formats...................................................................................................................................45
6.6.1 Measurement Profi es............................................................................................................46
6.6.2 Raw data................................................................................................................................47
6.6.3 SLC (Sing e-Look Comp ex) Data........................................................................................48
7. Instrument Specifications.....................................................................................................................51
8. References............................................................................................................................................52
9. Appendix A..........................................................................................................................................53
10. Demo Data Processing.......................................................................................................................54
10.1 Continuous Measurements..........................................................................................................54
10.2 Repeat Measurements..................................................................................................................54

1. Read First
First of a , thanks for buying this fascinating piece of hardware and software and we hope you can
conduct many interesting and troub e free measurements. If you have feedback p ease do not hesitate to
contact us ([email protected] or direct y one of the staff). Feedback from our users is a strong
e ement of our hardware and software evo ution.
1.1 EMC Notice
This device comp ies with Part 15 of the FCC Ru es and with RSS-210 of Industry Canada.
Operation is subject to the fo owing two conditions:
1. this device may not cause harmfu interference, and
2. this device must accept any interference received, inc uding interference that may cause
undesired operation.
Changes or modifications made to this equipment not express y approved by (GAMMA Remote
Sensing AG) may void the FCC authorization to operate this equipment.
This equipment comp ies with FCC radiation exposure imits set forth for an uncontro ed environment.
This equipment shou d be insta ed and operated with minimum distance of 500 cm between the
radiator (antenna in view direction) and your body. For proper radar imaging, no obstac e must be
between the antennas and the target area during image acquisition at a (shadow effects).
This transmitter must not be co- ocated or operating in conjunction with any other antenna or
transmitter.
1.2 Safety Guidelines
Fo ow these guide ines to ensure genera safety:
•Keep the working area c ear during insta ation and instrument operation.
•Wear safety g asses if you are working under any conditions that might be hazardous to your
eyes.
•Do not perform any action that creates a potentia hazard to peop e or makes the equipment
unsafe.
•Disconnect a power by turning off the power and unp ugging the power cord before insta ing
or removing a chassis or working near power supp ies
•Do not work a one if potentia y hazardous conditions exist.
•Never assume that power is disconnected from a circuit; a ways check the circuit.
•There are no user serviceable parts in the RF Assembly or the Instrument Controller Box.
The Instrument Controller Box must not be opened with the power cable attached!
1.3 Operating Safety
•E ectrica equipment generates heat. Ambient air temperature may not be adequate to coo
equipment to acceptab e operating temperatures without additiona measures.
•Ensure that the RF assemb y and Instrument Contro er cover is secure. The design a ows

coo ing air to circu ate effective y.
1.4 Manual Outline
This manua sha he p the user to setup and use the instrument but a so provides background
information on the instrument. Section 2 gives a quick access on the instrument. Section 3 provides
setup instructions and the basic commands needed to operate the instrument. Section 4 gives more
detai ed information on the instrument. Section 5 gives insight in the communication interfaces.
Section 6 summarizes the instrument specifications and Section 7 a ist of references and iterature.
Fina y in the Appendix A in Section 8 a temp ate for a measurement protoco is provided. Whi e
everything can be contro ed digita y, neverthe ess we recommend to keep a handwritten ogbook.

2. Background
The GPRI-II is the second generation instrument of the Gamma Portab e Radar Interferometer GPRI
[1,2]. The GPRI-1 was deve oped as a proof of concept and ater used on numerous scientific and
commercia campaigns. The new second generation instrument GPRI-II has improved performance and
is hardened for fie d measurements.
The GPRI deve opment at Gamma was initiated based on the perceived benefits of in-situ measurement
of deformation using differentia radar interferometry. Our extensive experience with sate ite
differentia interferometry has demonstrated successfu app ication of this technique for measuring
deformation due ands ides, pumping of oi and water, mining, g aciers, and tectonic motion.
However, when the deformation between repeat observations exceeds wave ength/4 the usefu ness and
interpretation of the data rapid y become difficu t. A ground-based instrument can be rapid y dep oyed
and obtain data with both high spatia and tempora reso utions that are particu ar y we suited to
measuring rapid deformation.
Un ike orbita SAR systems, in-situ measurement permit f exibi ity in the se ection of the observation
geometry. The geometry can be se ected to give maximum sensitivity to deformation a ong the ine of
sight. Observations from mu tip e aspect ang es can be combined to reso ve the deformation into
components a ong different ook vectors.
Path de ay variation due to tropospheric water vapor is the most significant cause of error in
deformation using differentia interferometry. A stationary instrument has the abi ity to acquire mu tip e
observations for mitigation of path de ay variations. Note that ground measurements have a shorter
path ength through the atmosphere than orbita observations a so eading to reduced error from this
source.
Mu tip e observations acquired over short time interva s have the advantage that decorre ation is
minimized by the shorter time interva s. Successive measurements can be processed to track non- inear
deformation within the scene.

3. Quick Introduction
3.1 Instrument Setup
The instrument setup needs to be stab e (consider a so wind!) and reproducib e (if repeat measurements
from a given position are foreseen). The standard setup of the GPRI-2 is on the supp ied heavy duty
Leica tripod. However it can a so be mounted on permanent pier or other structure. In any case there
must be sufficient room for the instrument to rotate (about 2.5 meters).
Figure 1: GPRI-II fully assembled. Instrument is aligned at 0
deg. azimuth position.
3.1.1 Leica heav -dut tripod
Insta ation of the tripod is the first step in setting up the GPRI2. The tripod egs shou d be initia y
fu y retracted. Take the tripod out of the canvas transport bag and take out the 3 stain ess stee rods.
1. Insta the stain ess stee support rods to the tripod to maintain the egs at a fixed 30 degree
ang e. These rods fit into the attachments at the bottom of each eg. The end of the rod is shaped
to fit into the s ots on the attachment points. A sma ocking arm on each attachment point must

be rotated to permit insertion of the rod. Once the rod is attached, rotate the arm back over the
rod ends and it wi ock into p ace.
2. The tripod egs are numbered 1,2, and 3 with abe . Make sure that you note the ocation of each
eg so that when you return to the site, the orientation of the tripod is identica . One eg of the
tripod shou d remain fu y retracted and this shou d not change. In s oping terrain, this eg
shou d be the eg with the highest e evation. The zero degree ook direction of the radar is in the
direction of eg 1.
3. Using the bubb e eve on top of the tripod, extend the other 2 feet of the tripod unti the tripod
top surface is horizonta . Remember to keep one eg of the tripod fu y retracted and on y
extend the other 2 egs.
4. Screw the feet through the ho e in the tip to the ground using anchor screws (6mm anchors).
5. Measure and note the extension of the egs for future repositioning.
Figure 2: Fi ature of rods to have tripod
legs at fi distance.
Figure 3: Tripod foot with
special tip that allows
screwing to the ground.
Figure 4: Tripod leg e tent
documentation.
Figure 5: Interface Plate of the Leica
Tripod with level and 5/8" screw.
3.1.2 Motor with leveler and tower
1. Mount the rotary positioner and eve ing assemb y on the tripod using the b ack 5/8” screw
interface of the tripod. The positioner has abe s with the numbers 1 and 3. Position this edge of
the positioner + eve er between tripod egs 1 and 3. Rotate the positioner and eve er assemb y
such that the edge of the positioner p ate is para e with the tripod stain ess-stee rod between
egs 1 and 3.

2. Make the antenna tower interface perfect y f at using the tribrach eve adjustment screws.
Note, the screw on side 1 is fixed and shou d never be change to not oose the abso ute height
reference. The arge bubb e eve on the positioner shou d be used to determine if the tower
mounting p ate is eve . Be sure to ook down from direct y above the eve to make sure the
bubb e is centered.
3. Power on the aser p ummet using the battery pack. If this is the first measurement, mark the
position of the aser on the ground for future repositioning. This point is precise y on the
rotation axis of the tower. If you are returning to the site, adjust the positioner and eve er so
that the aser beam hits the previous y marked rotation center
4. Remove the 4 socket screws on the tower mounting p ate, and mount the tower on the p ate.
There is an a ignment pin on the p ate that makes sure that there is on y one way to position the
tower. Screw the tower to the mounting p ate. When you remove the tower, be sure to screw the
4 screws back on to the p ate for future use and storage.
5. Define the antenna e evation ang e and set a six antenna ho ders according y. The antenna
i uminates about 60 degrees in e evation, Set the e evation ang e so that the beam center aims
at the area of interest. If there are areas that are significant y farther away, adjust the beam to be
centered on these areas.
Figure 6: Side view of the Tripod - leveler -
positioner - Antenna Tower setup. The leveler is
adjust by rotating the red knobs. The black
screw is to fi the knob setting. At the bottom of
the motor, the connector for the laser battery is
indicated.
Figure 7: Top view of the positioner. The 4 socket
screws need to be removed before mounting the
antenna tower.

Figure 8: Bottom of Antenna Tower mounted
on the motor. Visible is the level, the 4
he agon socket screws and the knob
enforcing the defined tower orientation.
3.1.3 RF Unit
1. Mount the RF Unit on monting brackets at the back of the Antenna Tower. Use the 2 screws on
the back to secure the RF unit
2. P ugin the GPS Antenna cab e to the BNC connector. The GPS receiver is ocated on the
rotation axis of the tower.
Figure 9: RF Assembly mounted at the back of the
Antenna Tower. On the left side the GPS Antenna
mounted on top of the Antenna Tower is plugged, on the
right side the Antenna cables, at the bottom the cable to
the Instrument Controller and Power Unit.
here are no user serviceable parts in the RF Assembly or the Instrument Controller
Box. he Instrument Controller Box must not be opened with the power cable
attached!

3.1.4 Antenna
1. Take each antenna out of the tube by oosening the 2 thumb screws. NOTE it is important that
you push them out with the antenna cab e p ug in front to avoid damaging the antenna cab e.
2. Mount the antennas one by one on the corresponding antenna ho ders. Make sure you use a fix
order for the antennas (TX, RX1, RX2) to avoid phase effects due to s ight y different antenna
characteristics. It is recommended that you note the seria numbers of each antenna and if it is
the top (TX), center (RX1), or bottom (RX2) of the tower. Each antenna has a s ight y different
pattern and phase and so it is strong y recommended to use the same antennas for TX, RX1, and
RX2 for each measurement.
3. P ugin the 3 antennas to the appropriate port on the side of the RF assemb y. The antenna cab es
have quick-connect SMA connectors. It is very important that these be pushed on gent y and
without being ti ted re ative to the connector axis or e se they wi be damaged. Inspect the
connector before each use to make sure a the connector go d springs are not damaged or bent.
!! Never detach the antenna ho ders as you might oose the a ignment precision of the antennas. These
have been precise y positioned on the tower to insure that the antennas are para e
Figure 10: Closeup of the Antenna holder and
Elevation Angle setting.
3.1.5 Instrument Controller and Power Unit
1. P ace the Pe ican case c ose to the tripod at a dry and convenient p ace. The feet can be screwed
to the ground if necessary.
2. Make sure the Instrument Contro er is switched off.
3. Connect the Instrument Contro er with the RF Unit (orange cab e).
4. Connect the Instrument Contro er with the motor (2 cab es).
5. Connect the Instrument Contro er to the network. The contro er decides depending on the
traffic which net configuration wi be se ected.

6. Switch Instrument Contro er on.
here are no user serviceable parts in the RF Assembly or the Instrument Controller
Box. he Instrument Controller Box must not be opened with the power cable
attached!
Figure 11: Instrument Controller and Power Unit in Pelican case. Connectors uper line from left to
right: WLAN (not connected), Ethernet, RF Unit, Power. Lower line from left to right: Instrument
Power Switch, USB, Motor Control, Motor Power.
3.2 Operating the Instrument
Communication with the instrument in the fie d is through TCP/IP. The easiest so ution is to connect
the instrument to an Ethernet Switch with attached aptop. In princip e its a so possib e to use a crossed
Ethernet cab e but this has some disadvantages. In the ab it is a so possib e to connect screen and
keyboard after opening the Pe ican case.
The GPRI2 supports two communication ayers, SSH (Secure She ) and HTTPS (Secure Web). It is
good po icy to have a so a ogbook for the instrument and take pictures for documentation. A ist of
items to record is given in Appendix A.
3.2.1 Operating the instrument through SSH
To contro the instrument through SSH a SSH c ient software is necessary. Preferred is to access from a
Linux system that a so a ows to export the window environment of the instrument. Though it is a so
possib e to access the instrument pure y through the she using e.g. Putty. In the fo owing we assume a
Linux system accessing the instrument but the commands are the same for a pure she connection.
P ease refer to Section 5.4 for the detai ed instrument software reference. Program parameters are
provided for easier reading but needs to be adjusted to the individua case.

1. Login to instrument:
ssh -X -l gpri2 192.168.1.7x
2. Check avai ab e disk space for data. The data are stored in their own disk partition ca ed /data:
df /data
3. Move to the data directory
cd data
4. Initiate home run of the positioner (check first visua y that the instrument can move free y and
the cab es have enough room!):
home_run.py
The instrument is now ooking at 0 degrees instrument azimuth ang e. Ang es increase
c ockwise. Furthermore you may want to check system and gps status to make sure these
components are we attached and working:
chupa_status.py
tscc_status.py
gps_message.py
Temperatures shou d be be ow 50° and 2 ines of GPS messages shou d be shown.
5. Determine the start and stop ang es for the scan by moving the antenna around. Be aware that
about 3 degrees are needed on both sides of the scan for rapid motion of 10 degrees/sec,
otherwise motion is at .5 deg/sec
move_abs.py -30
6. Create a directory for your site, e.g. the ocation name, and move into
mkdir Rosenlaui
cd Rosenlaui
7. Define the measurement parameters and setup the corresponding measurement profi e. The
profi e contains information on the transmitter chirp, angu ar scan, speed, and receiver
attenuation. See Tab e 1 for the description. Depending on the maximum range you want to
observe se ect the corresponding chirp rate in Section 6. (Tab e 2).
You can copy a temp ate preference fi e from /usr/share/gpri/profi es. Its a good idea to give it a
descriptive name (site, name), especia y if you do repeat measurements.
cp /usr/share/gpri/profiles/gpri_2ms.prf site_2ms.prf
8. Edit the profi e to ref ect your settings for IMA_atten_dB, STP_antenna_start,
STP_antenna_end and antenna_e evation. The setting TX_power must be “on” for
measurements, or “off” for isten on y. Description of the va ues is given in Section 6.6.1 .
9. Run isten on y first to check for other transmissions.
gpri2_capture_utc.py gpri_2ms.prf raw/20110714 \
1 now 1 -p slc/20110714 -m mli/20110714 \
-d 5 -r 10 -s .3 -e .5
10. Then disp ay the processed data:
eog mli/20110714/20110714_083514*.ras
gpri2_plot.py gpri_2ms.prf raw/20110714/20110714_083514.raw
11. If no foreign signa s are present start active measurement to derive gain settings (don't forget to
set power on in the prf fi e!):
gpri2_capture_utc.py gpri_2ms.prf raw/20110714 \
1 now 1 -p slc/20110714 -m mli/20110714 \
-d 5 -r 10 -s .3 -e .5

12. Then disp ay the processed data:
eog mli/20110714/20110714_084014*l.ras
gpri2_plot.py gpri_2ms_ro.prf raw/20110714/20110714_084014.raw
Check signa eve s in gpri2_p ot to make sure there is no saturation and that there is sufficient
signa and adjust attenuation setting in the prf fi e. Redo step 11./12. unti gain is ok
13. If attenuation setting is ok go for repeat measurements :
gpri2_capture_utc.py gpri_2ms.prf raw/20110714 \
1 now 180 -p slc/20110714 -m mli/20110714 \
-d 5 -r 10 -s . -e .5
14. Generate a differentia interferogram from se ected SLC fi es. It makes sense to check
upper/ ower antenna pairs and some succeeding pairs for data qua ity.
create_offset slc/20110714/20110714_084014l.slc.par \
slc/20110714/20110714_084014u.slc.par \
int/20110714_084014l_20110714_084014u.off 1
Parameters to provide: dummy_create_offset 0 0 48 48 256 256 7.0
SLC_intf slc/20110714/20110714_084014l.slc \
slc/20110714/20110714_084014u.slc \
slc/20110714/20110714_084014l.slc.par \
slc/20110714/20110714_084014u.slc.par \
int/20110714_084014l_20110714_084014u.off \
int/20110714_084014l_20110714_084014u.int 5 1 0 - 0 0
multi_look slc/20110714/20110714_084014l.slc \
slc/20110714/20110714_084014l.slc.par \
mli/20110714/20110714_084014l.mli \
mli/20110714/20110714_084014l.mli.par 5 1
rasmph_pwr int/20110714_084014l_20110714_084014u.int \
mli/20110714/20110714_084014l.mli 1016 1 1 0 1 1 0.4 0. 5
eog int/20110714_084014l_20110714_084014u.int.ras
cc_wave int/20110714_084014l_20110714_084014u.int \
mli/20110714/20110714_084014l.mli - \
int/20110714_084014l_20110714_084014u.cc 1016 1
rascc int/20110714_084014l_20110714_084014u.cc \
mli/20110714/20110714_084014l.mli 1016 1 1 0 1 1 .1 .9 0.4 0. 5
15. If app icab e create interferograms with previous campaigns to check data consistency. Note
that most ike y the data need to be coregistered to correct for sma offsets in the azimuth ang e
a ignement. Use on y inear offsets for the offset estimation. The fo owing procedure is used to
coregistered the second s c to the master (->rs c):
create_offset slc/20110714/20110714_084014l.slc.par \
slc/20110714/20110714_084014u.slc.par \
int/20110714_084014l_20110714_084014u.off 1
slc/20110714/20110714_084014l.slc \
slc/20110714/20110714_084014u.slc \
slc/20110714/20110714_084014l.slc.par \
slc/20110714/20110714_084014u.slc.par \
int/20110714_084014l_20110714_084014u.off
int/20110714_084014l_20110714_084014u.offs
int/20110714_084014l_20110714_084014u.snr
offset_fit int/20110714_084014l_20110714_084014u.offs

int/20110714_084014l_20110714_084014u.snr
int/20110714_084014l_20110714_084014u.off
int/20110714_084014l_20110714_084014u.coffs - - 1 0
SLC_interp slc/20110714/20110714_084014u.slc $slc1.par \
slc/20110714/20110714_084014u.slc.par \
int/20110714_084014l_20110714_084014u.off \
rslc/20110714/20110714_084014u.slc.rslc \
rslc/20110714/20110714_084014u.slc.rslc.par \
now that the interferogram is created using the master s c and the rs c as in Step 14 above.
16. Backup data. e.g. with secure copy or rsync to a network attached disk. Use ionice to avoid disk
timeouts whi e acquiring data:
ionice -c2 n7 scp -r Rosenlaui 192.168.1.1:backupdirectory/
ionice -c2 n7 rsync -av Rosenlaui 192.168.1.1:backupdirectory/
or p ug an externa usb disk and mount it. To find out the device id of the disk (most ike y
/dev/sdb1)
dmesg | tail -n 50
and ook out for ines such as
[1295858.2750 7] sd 16:0:0:0: [sdb] Assuming drive cache:
[1295858.275046] sdb: sdb1
or sometimes its just
[1295858.275046] sdb:
Mount the device on /mnt for user gpri2 with
sudo mount -o gid=1000,uid=1000 /dev/sdb1 /mnt
The data can now be copied to and from /mnt.
ionice -c2 -n7 cp -av Rosenlaui /mnt
Make sure you unmount the device at the end
sudo umount /mnt
17. Always do a positioner home-run before you switch off the instrument:
home_run.py
18. and shut down the Instrument ontroller properly
sudo shutdown -P now
and switch off the power at the yellow Pelican box.
3.2.2 Operating the instrument through HTTPS
The Instrument Contro er provides a web based user interface. It can be accessed through secure http
(https) and needs authentication. Detai ed description is given in Section 5.2 . Here we describe the
minima steps to run a measurement and check data qua ity.
1. Access instrument by browsing to the IP address of the instrument (Figure 12). Ignore the
certificate comp aint and provide username and password.
2. Check the entries in the Accordion Pane on the right (temperatures and GPS status) and fina y
do a homerun of the motor (Figure 13) to initia ize the Home Position of the motor.
3. Determine the start and stop ang es for the scan by moving the antenna around using the Motor
Menu in the Accordion Pane on the right. Be aware that about additiona 3 degrees are needed
on both sides for the motor to acce erate and dece erate.
4. In the Measurement Contro Tab, start the measurement setup (Figure 14). The measurement

form is setup setp-by-step when the corresponding data is provided (Figure 16)
•First you have to either se ect an existing Project Directory or create a new one. The
directory is/wi be a ocated in the data directory.
•Then you have to se ect an existing measurement profi e or create a new one.
Existing profi es can be edited (Figure 15). The profi e wi be store in the Project
directory. Profi e parameters are described in Section 6.6.1 .
•Provide information on measurement timing. For initia tests sing e measurements
conducted now are convenient.
•It makes sense to process the data to SLC (sing e ook comp ex data) and produce
MLI (mu ti ook intensity) images for qua ity contro and check if the signa eve is
sufficient but not saturating (attenuation setting in the profi e). Data wi be stored in
slc/date/date_time.slc and mli/date/date_time.mli.
•Start the measurement.
•The og of the measurement is shown in the tab be ow the Measurement Contro Tab
in the Data Capture Log and the images can be quick y accessed in the Images Tab.
•Do an initia measurement with TX_power switched off to check for RFI (→ b ack
image) and then check the attenuation eve required for the scene.
•When the images are satisfying repeat observation can be initiated preferab y by
adding the settings as a Repeat Task on the Schedu er (C ick the corresponding ink,
Figure 16). So the number of measurements shou d in genera be 1, if you want to do
repeat measurements its genera y better to use the Schedu er. The task schedu er
provides access to the Cron Settings. The settings to measure every 10 minutes are
shown in Figure 17.
5. To check qua ity it is worthwhi e to compute interferograms of the acquired data, at east for an
upper/ ower antenna pair and two successive acquisitions at the same antenna. The processing
can be initia ized in the Compute Interferogram Tab (Figure 18). Again first the project
directory needs to be se ected, providing a ist of a avai ab e SLC images for pair se ection. If
the data were not acquired during the same campaign its very ike y that they have a s ight
offset in azimuth and need to be coregistered. Uncheck the checkbox in that case! The resu ting
interferogram images can again be found in the Image Tab be ow.
6. Data can be retried from the directory browser or the fi e manager, accessib e through the Main
Menu option System Access (Figure 19).
7. Make sure to do a home run before switching the instrument off from the comand ine (sudo
shutdown -P now) and fina y the switch at the ye ow Pe ican case.

Figure 12: Instrument Web Access Login.
Figure 13: Motor Status Accordion
Panel.
Figure 14: Initial Measurement Control Tab.

Figure 16: Measurement Settings. The button starts the measurement as a single task, the links allow to
transfer the settings to the Repeat task Scheduler.

Figure 17: Recurrent Task Menu (Cron Interface).
Figure 18: Compute Interferogram Tab.
Figure 19: Main Menu.