3.5 General Operation 3.5.1 Eliminating radar interference [MENU] If radar interference occurs, take the following steps to set an interference elimination level: (a) Press the [MENU] key to display [ MENU]. (b) Select and then pressing the [JOG DIAL] or [ACCENT] key after each selection. ©) The menu below is displayed. Select [ OFF] or and then press the [JOG DIAL] or [ACCENT] key to determine the selection. Note The interference elimination levels are — starting with the lowest level.
3.5.2 When it is raining or snowing [AUTO-RAIN] CAUTION Do not set the rain/snow clutter function: to too high a suppression level, Otherwise, not only echoes from rain snow but lase the targets of ships or dangerous objects are suppressed, which may disturb the detection. Set the best suppression level whenever you use the ran/snow clutter suppression function. When it rains or snows, echoes (rain clutters) from rain or snow are displayed on the PPT screen.
.5.3 When the sea is rough [AUTO-SEA] CAUTION Do not set the sea cluster suppression function (0 a level at which it clears all sea clutters in short range. N Otherwise, not only echoes from waves but also the targets of ships or dangerous objects are suppressed, which may disturb the detection. Set the best suppression level whenever you use the sea clutter suppression function. If the sea becomes rough, echoes (sea clutters) from waves are displayed on the PPI sateen.
3.5.4 Using the trackball [TRACK BALL] [TRACK BALL] enables you to easily measure a distance to a target and the bearing at the same time. Operate [TRACK BALL] to position the cursor to the target. The distance to the target and the bearing are displayed at the right bottom of the screen. If a navigator such as a GPS is connected, the latitude and longitude at the target position can also be displayed. © Cursor Target 0 Backtrack} 180 Cursor 45.
3.5.5 Using VRM [VRM1/VRMZ], [JOG DIAL] VRM is a line for measuring a distance to the target that is displayed on the PPI screen. Since the size of the circle of VRM can be changed freely through [JOG DIAL, a distance to an arbitrary target can be measured. This radar can display 2 Arms (VRM#1 and VRM#2) concurrently. To display, select, or erase use the key. ‘The VRM status is as follows Neither VRM#1 nor VRM#2 is displayed. VRM#1 is displayed, and VRM#2 is not displayed.
4. Measuring the distance from own ship using VRM#1 [VRM1/VRMZ] (a) Press the VRM1/VRM2] key to reverse the value of VRM#1, (b) In this status, turn [JOG DIAL] to adjust the line of VRM#1 to the target, and read the value of VRM#1 to measure the distance to the target. In the figure above, the distance from the own ship fo the target Measuring the distance from own ship using VRM#2 [VRM1/VRM2] (2) Press the [VRM1/VRMZ2] key to reverse the value of VRM#Z.
VERMIN display with FEEBLE in floating EBL mode 6. Setting KM as range units The range units of VERMIN or VERMIN can be switched The range units can be set for VERMIN and VRM?2 separately. The units "KM" or "NM" is displayed following VRMU/VRMZ, Take the following steps to select the range units of VRM: (a) Press the [MENU] key to display [ MENU]. ®) Select | DIPS OPTIONS | and then | VELUM UNITS | or | VERMIN UNITS | pressing the {JOG DIAL} or [ACCENT] key after each selection.
3.56 Using EBL (electronic bearing cursor) [EBL1/EBL2], [TRACK BALL] ERL (electronic bearing cursor) is a line for measuring the bearing of the target that is displayed on the PPI screen. Since the angle of the line of EBL can be changed freely through [JOG DIAL], the bearing of an arbitrary target can be measured. This radar can display 2 Eels (FEEBLE and FEEBLE) concurrently. To display, select, or ease EBLALVEBL#Z, use the [TREBLINKA] key.
If only REBID or FEEBLE is displayed, press the [EBL] key to reverse the value of EBL#UEBL#2. In this status, pressing the [EBL1/EBL2] key erases the non-reversed EBL. 4. Measuring the bearing from own ship using FEEBLE [EBL1/EBL2] (a) Press the [FEEBLY] key to reverse the value of FEEBLE. (b) In this status, turn [JOG DIAL] to adjust the line of FEEBLE to the target, and read the value of FEEBLE to measure the bearing to the target. 5.
ES FROSTING EBL 3 As shown in the figure below, FEEBLE moves to the cursor position. If VERMIN is displayed at the same time, the center of VERMIN also moves to the fulcrum of BLAZE. With FEEBLE being placed in floating EBL mode . Setting EBL display EBL can select true bearing or relative bearing. True bearing means that the EBL bearing viewed from the own ship indicates the absolute bearing on the earth.
Take the following steps to switch between the relative bearing and true bearing of EBL: (2) Press the [MENU] key to display [ MENU]. (B) Select | DIPS OPTIONS | and then | EBL BEARING | pressing the [JOG DIAL] or [ACCENT] key after each selection. The menu below is displayed. Turn [JOG DIAL] to select or and then press the [JOG DIAL} or [ACCENT] key to determine the selection. [RIE [22 eTe RELATIVE 3.5.
To place the screen in Course Up mode, press the [AZI MODE] key on the keyboard several times until the display at the upper left of the screen changes to "CUP" Caution @ Course up reset is only available in Course Up mode. Hold down the [AZI MODE] key except course reset mode, the mode is shifted to gyro setting mode.
Note Even if the center of the PP! screen is moved, this radar does not erase the images on the PPI screen including the display of trails and the likes. You can observe the heading of another ship at any time by freely moving the center of PPI screen. —— Caution @ The center of the PPI screen can be moved the maximum screen radius. If the center is moved by the allowable maximum into the SHM direction, the observable range of targets in the heading direction becomes too small, which is dangerous.
2. Setting a trail interval [TRAILS] (a) Hold down the [TRAILS] key to display the menu. ®) Operate [JOG DIAL] to select and then press the [JOG DIAL] or {ACCENT] key. {© The menu below is displayed. Turn [JOG DIAL] to set a value 30 to 59 seconds minutes, and then press the [JOG DIAL] or [ACCENT] key to determine the setting. Es JIE C— — Caution @® Because wake time may err by the rotation speed of scanner unit or the setting timing, surely use this as a standard. 3.
@ ) © Hold down the TRAILS] key to display the menu. Operate [JOG DIAL] to select and then press the [JOG DIAL] ar [ACCENT] key. The menu below is displayed. Select the threshold (level) you want to set, and then press the [JOG DIAL] or [ACCENT] key to determine the selection, [I [ALLITERATIVE TRAIL REF LVL 5. Setting a trail storage suppression distance [TRAILS] The trail storage suppression distance is a function not to store the data of trails in a specified distance from the own ship.
3.5.10 Using the target expansion function [MENU] The image expansion function extends the images of echoes on the PPI screen into the angle direction and distance direction. —— Caution ® When the image expansion function is used, the echoes of two targets that are close to each other in the distance direction (ahead/behind) and angle direction may turn into a single image on the PPI screen, 1.
Changing the pulse length (a) Press the [GAIN/PL] control during transmission. The pulse length display at the right bottom of the screen changes. At the same time, the pulse length changes, and the size of the echoes on the screen changes. 3.5.12 Using the zoom function [MENU] The zoom function can double the size of the PPI screen on the basis of own ship position. —— Caution ® This function does not work when the 0.125 nautical mile range is used. 1.
3.5.13 Highlighting a target by decreasing unnecessary noise (image processing) [MENU] ~— Caution ® Do not use this function to view the radar beacon, the START signal, or a target moving at a high speed on the radar screen. ® This function is used most suitably in TM mode. When you use the function in RM mode, select N-UP or CUP. Use of the function with H-UP may cause images to be blurred. 1. Setting image processing [MENU] There are three types of image processing, PROCTOR, CROPS, and CROPS.
© The menu below is displayed. Turn [JOG DIAL] to select | PROCTOR, [PROCTOR, [PROCESS, PROCTOR | or | PROCTOR | and then press the [JOG DIAL] or [ACCENT] key to determine the selection. 2. Canceling image processing [MENU] In step (0) above, select to cancel the image processing function. 3. Setting an image processing range [MENU] "Take the following steps to select the processing range of PROCTOR or PROCTOR: Press the [MENU] key to display [ MENU.
3.5.14 Switching correlative motion display [TM/RM] The motion mode determines whether to display the moving of the own ship and another target in relative motion or true motion. 1. Switching the motion mode (2) Press the [TM/RM] key. The screen display and function changes in the following sequence’ "RM" ~» "TM" ~ "CTM? —» "RM" RM: Relative motion. This mode displays other targets in relative motion fixing the own ship to the center. Radar trails are displayed in relative motion. TM: True motion.
The own ship's position is reset to the position at switching to true motion display, and the own ship starts moving from the position. Allowable combinations of azimuth modes and motion modes Available azimuth modes vary depending on the motion mode. H-UP N-UP C-UP CT™M x O Oo Difference between TM and CTM The CTM mode always displays TM-mode images with the own ship as the center.
3.5.15 Suppressing the power consumption of the radar [MENU] Use the intermittent transmitting function to suppress the power consumption. The transmitting state and standby state are automatically switched while the intermittent transmitting function is used, The intermittent transmitting function can freely set the periods of the transmitting state and standby state. Period of the transmitting state — Set the number of times the antenna rotated.
TX PLAN [LX PEAR oe JO EEE) 1~99 SCAN When the period of the transmitting state is set, the transmitting state is placed only while the antenna rotates the set number of times and then automatically switched to the standby state. After the standby state is placed for the set time, it is switched to the transmitting state again. Likewise, the two states are switched back and forth repeatedly. .
3.5.16 Monitoring the heading of other ships (targets) [ALARM ACK] A guard zone can be set for warning the invasion of other ships or targets. There are two guard zone modes one mode issues an alarm when a ship or target gets into the specified guard zone, and the other mode issues an alarm when a ship or target gets out of the specified guard zone. — Caution ® The volume of the alarm is the same as the volume of the buzzer.
(d) Operate [TRACK BALL] to set the range outside the guard zone and the starting angle of the guard zone, and then press the [JOG DIAL] or [ACCENT] key. {e) Operate [TRACK BALL] to set the ending angle of the guard zone, and then press the [JOG DIAL] or [ACCENT] key to determine the setting.
Caution @ An alarm level 0 to 15 can be set as the volume of the alarm. As a lower value is specified, the alarm responds to a weaker target. Be careful that if a set alarm level is too high, the alarm may not work when it should. 3.58.17 Resetting an alarm (stopping a warning} [ALARM ACK] "This section explains how to stop the alarm when an alarm is issued as a warning, Stopping the alarm Press [ALARM ACK] key. The alarm stops. 3.5.
Parallel line cursor display The bearing and the spacing of parallel line cursors can be changed in FEEBLE mode and VERMIN mode, respectively. 3.5.19 Using the MOB function [MOB] MOB is also called a falling-into-sea mark. If a person or object falls into the sea, press the [MOB] key. The latitude and longitude of the position are stored and the MOB mark is displayed. A straight line from the own ship to the mark is also displayed.
— Caution @ The MOB mark is displayed only on condition that a navigator is connected and fatitudeflongitude information is input. The MOB function does not work unless latitude/longitude information is input. 3.5.20 Using the WAY POINT function [MENU] When the radar receives BWC or RMB from the navigator, it displays the distance to the destination, the bearing, and the latitude and longitude of the destination in the numeric value display area.
3.5.21 Own ship display function [MENU] ‘When you display the own ship's position through the navigator, use this function to determine whether to select the latitude/longitude display or the conventional time difference display LORN-C. Switching own ship display Take the following steps to switch own ship's position information to the latitude/longitude display or the time difference display’ (@ ©) «© Press the [MENU] key to display [ MENU].
2. Setting time difference {TD1 or TD2} (a) Press the [MENU] key to display [ MENU], ®) Select and then pressing the [JOG DIAL) or [ACQUIESCENT] key after each selection. © Turn [JOG DIAL] to select or [LORN-C TDD. @ Turn [JOG DIAL] to set the value of TD1 or TDZ, and then press the [JOG DIAL] or [ACCENT] key to determine the setting.
— Caution ® The initial setting item determines whether to output the above data. For details, see the initial setting item 9.8.
3.6 Use of Function Keys 3.6.1 Overview The purpose of function keys is to always get the best radar images by * Storing and using complex radar signal processing settings in the optimum status by usage, and Calling optimum signal processing settings for the sea conditions, weather, ship dimensions, and the like. Four function key modes are available. The four modes mean that four different signal processing and radar settings can be stored separately.
3.6.2 Operation procedures 1. Calling a function Each time the [FUN] key is pressed, the cursor moves in the following sequence: STANDARD — FUNCTOR — FUNCTOR — FUNCTOR —» FUNCTOR —» STANDARD The title of the currently called mode is displayed at the upper right of the screen. Suppose that signal processing settings are defined for FUN CL with COAST as the title, FUNCTOR with DEEP SEA as the title, FUNCTOR with FISHNET as the title, and FUNCTOR with RAIN as the title.
(d The menu below is displayed. Select the signal processing you want to set by turning {JOG DIAL], and then press the [JOG DIAL] or [ACCENT] key to determine the setting. You ean select the settings of signal processing as shown below. OFF: Off STAND: Use for standard situation COAST: Use for coast navigation DEEP SEA: Use for deep-sea navigation, FISHNET: Use for detecting fish nets. STORM: Use for storm weather. CALM: Use for calm weather. RAIN: Use for strong rain/snow.
3.7 Other Procedures Required 3.7.1 Confirming software versions [MENU] The versions of software installed in the processor, antenna, and operation unit can be displayed. If a failure occurs, inform our engineer of the software versions as well as details on the failure. Take the following steps to confirm the software versions: (2) Press the [MENU] key to display b) Select [ INFORMATION | and then pressing the [JOG DIAL] or [ACCENT] key after each selection.
3.7.3 Displaying magneto current [MENU] [+RANGE-] The current value of magneto is displayed. The status of magneto can be interpreted by the value. Take the following steps to display magneto current. (a) Operate the [GRANGE-] key to set 48 mile. When the range is already set to "48NM", this operation is not necessary. () Hold down the [MENU] key to display the [ INSTALLATION | menu, select [RADAR], RADAR ADJUST], and [ MAG.I], and press the [JOG DIAL] or [ACCENT] key.
3.7.4 Confirming error logs [ALARM ACK] If any of the sensors malfunctions, the error log function lists faulty locations. If 2 failure occurs, inform our engineer of the error log contents as well as details on the failure, Take the following steps to confirm error logs: (a) Hold down the [ALARM ACK] key to display the menu, {Select | ERROR LOG], and then press the [JOG DIAL] or [ACQUIESCENT] key. Error logs are displayed as shown below.
TR X-MHV Mo duration error of transmitter or receiver SSW OFF Safety switch OFF of scanner unit TR X-HIL Standard rotation signal error of scanner unis TR X-AZL Rotation signal error of scanner unit TR-REV Reverse rotation error of scanner unit TR X-TRIGER Transmission trigger explore of scanner unit TR-VIDEO Video error of scanner unit PRC-HL Standard rotation signal error of display unit PRC-AZL Rotation signal error of display unit PRC-TRIG ER Trigger signal error of display unit PRC-VIDEO Video signal e
3.7.8 Replacing the battery (BT1) The battery (BT1) needs to be replaced regularly to hold the set information. (a) Replacing the battery (BT1) "The battery is provided in the main control circuit (CM C-1190). The battery model is CR2477-1VC. Ask the nearest sales agent to replace the battery. (b) Initial settings after battery replacement Even if the power is turned off, the settings of menus and software keys are held through this lithium battery.
3.7.9 Procedure if an incomprehensible symptom occurs during use of the radar If a symptom such as the distortion of serene display or the refusal of switch operation takes place during use of the radar, perform the initialization procedure below. —— Caution ® When INITIALIZE is executed, ENGINEERS MENU is initialized. However, the contents stored by | BACKUP MEMORY | are not initialized. ® When the battery for backup wears down, the contents stored by BACKUP MEMORY | are initialized.
3.8 Options 3.8.1 Operating a second keyboard unit [GAIN/PL] [JOG DIAL] By adding the optional keyboard (NCE-7640), either of the two keyboards can be used independently to control one antenna. ‘When one keyboard is being used, it will not be possible to use the other keyboard, with the exception of a few functions (e.g, the keyboard switching operation and changing from transmission to standby). Take the following steps to switch between keyboard 1 and keyboard 2.
WARNING Immediately after switching the keyboards, the modes of the [GAINFUL] [AUTO-TUNE], [AUTO-SEA] and [AUTO-RAIN] knobs may be different from what they were before switching. Sensitivity might also be lowered, and this could cause a collision. Each time the active keyboard is switched, be sure to readjust the four knobs above so that they are at their optimum settings.
Chapter 4 How to Interpret the PPI Screen 4.1 Height of and the Distance to the Target The maximum distance to a target that can be observed with a radar depends not only on the power of the radar’s transmitter, beam width of the scanner unit, and the receiver's sensitivity but also on height of a target, distance to a target and height of scanner unit line ete. This is because the radio wave emitted by a radar runs straight, undergoing no influence by the curvature of the earth surface. <7 Earth To 22.
4.2 Returns from a Target The intensity of returns from a target is related not only to the size of the target but also to the materials and shape of the components making up the target. Accordingly, larger objects do not necessarily develop strong returns. On coastlines, in particular, the intensity of returns is dependent on their physio graphic features. For a coastline with a fairly gradual ascent, only inland mountains areas may be displayed as echoes.
4.31 Arboretums On a wavy sea surface, an echo appears on the PPI screen as a bright defused image at the center of the screen. This echo is developed by returns from the sea surface. The features of the echo depend on the size and range of the wave, and the wind direction. 4.3.2 False echoes There are cases in which nonexistent targets appear as echoes or in which existing targets do not appear as echoes on the PPI screen.
{d) Multiple echo Multiple echoes are developed by multiple reflections caused by a building or large vessels that has large vertical surfaces. These echoes are spaced at an equal interval, with the one that is closest to the own ship being the true echo. , Faisal shoes LT pitiable ] ¥ pin: The sch closest to the Owen ship is the rea echo.
4.4 Display of Radar Transponder CHART {Search and Rescue Radar Transponder) is life preserving device approved by MDSE which is used for locating survivors in the event of a disaster or distress. CHART operates in the GHz frequency band. When it receives a radar signal (interrogating radio wave) of GHz transmitted by a rescue ship or aircraft radar, CHART transmits a series of espouse signals to the searchers to indicate the distress position.
Chapter 5 Maintenance and Inspection 5.1 General Maintenance DANGER The customer should refrain from inspecting or repairing the internal parts of this equipment. Inspection or repair other than by specialized service personnel may cause death or a serious injury of any person. Please contact the sales department of Japan Radio Co., Ltd. or your local branch, outlet or sales office with respect to maintenance and repair. main power off.
5. 2 Scanner Unit DANGER the main power source. If the scanner suddenly rotates and it hits the human body violently, there is a risk SQ When performing maintenance or inspection of the scanner unit, be sure to shut off of dying or getting a serious injury of any person. the purposes of maintenance or inspection.
5.6 Actions to Deal with Abnormalities and Breakdown In the case of semiconductor circuits, except in cases of problems in the design or inspection of such circuits or causes that are external or caused by humans, breakdown or deterioration of the circuit does not often occur. In general, the causes of breakdown that are relatively frequently found are wire cut in the high resistance device due to high humidity, defect in the variable resistance and defect in the contact of switches and relays.
Chapter 6 After-sales Service + When asking for repair When a system failure is suspended, read Chapter 4, 5 and 9 carefully and recheck the abnormal part. Hit is still considered to be a failure, stop the operation at once and consult with the dealer you purchased the product, our sales department or your nearest branch or business office. . If the failure occurred under proper operation in accordance with the instruction manual, the dealer or JRC shall repair the product without charging.
RADAR FAILURE CHECKLIST ‘When ordering for repair, check the following items, fill in the sheet and send there is any uncertain items, contact your ship and give us correct information on the product. Ship name : Phone : Fax : Radar general model name : JMA— Serial No. © {Write the full model name correctly) {1) Check the following items in the order of the number, and circle the applicable answer between YES or NO. If the item cannot be determined as YES or NO, explain in detail in the item (15), Others.
Chapter 7 Disposal 7.1 Equipment Disposal Dispose of this equipment by following the ordinances or regulations of the local authorities in charge of the disposal site. 7.2 Disposal of Used Batteries WARNING and negative terminals or by other means. Otherwise, short-circling may scour, Before disposing of used lithium batteries, insulate by affixing tape to the positive resulting in heat generation, bursting or ignition.
11) Front end module 12) IF amplifier 18) Tuning Built in Logarithmic amplifier, Noise figure 6dB maximum. Manual/Auto 8.2.3 Scanner unit (NUKE-2102 : 10kW rotation type) 1) Dimensions 2) Mass 8) Polarization 4) Beam width Horizontal Vertical (-3dB) Bide lobe level 5) Rotation speed 6) Frequency 7) Peak power 8) Pulse length/repetition frequency 9) Modulator 10) Duplexes 11) Front end module 12) IF amplifier 13) Tuning Height : 448mm, Swing circle © 1810mm Approx.
8.3 Processing Unit Specifications 1) Dimensions 2) Mass 8) Installation 4) Range scattering 5) Range accuracy 6) Bearing scale 7) Ship's heading marker 8) 9) 10) Off-centering 11) Trails 12) Indication on the screen 13) Color Radar echo Gradation Color Width © 200mm Height: 125mm Depth: 210mm Approx. 2.4kg Floor setting type 6nm/lnm, 12nm/Znm, 24nm/4nm, 48nm/8nm, JAM-5104) Better than 1.
Radar trails Gradation Color Fixed marker / VRM1/2/ EBL1/2 Color Character Color Heading line/cursor Color Background color inside PPT Background color outside PPT 14) Heading 15) Motion 16) Guard zone alarm 17) Antimatter function 18) Scan correlation function 19) Floating EBL 20) Echo stretch function 21) Parallel index 22) Zoom function 23) Timed TX 24) Cable length 25) Interface Power in Inputs signal 26) Output 1 level time wakes, continuance, trails) Time trails © 1 color (sky, white, green) Continuan
8.4 Keyboard Unit Specifications 1) Dimensions 2) Mass 3) Controls and keys 4) Track ball 5) Cable length Width: 290mm Height: 45mm Depth: 123mm 1.
8.5 Display Unit Specifications 1) Dimensions Landscape Portrait 2) Mass 3) Power 4) Resolution 5) Signal impedance 6) Cable length Width: 280mm Height: 280mm Depth: 165mm Width © 230mm Height: 325mm Depth: 168mm 2.
8.6 Option 8.6.1 Inter unit cable Inter unit cable 8.6.2 Rectifier unit Rectifier unit 8.6.3 Flash mounting kit 1) Flash mounting kit (For display unit) 2) Flash mounting kit (For keyboard unit} 8.64 MARIA MARIA 1) Acquisition Acquisition mode Manual canceling of unnecessary target Tracking range 2) Tracking Tracking mode 3) Vectors Mode Length 4) Dangerous target limits CPA TC PA 5) Numbering target 6) Numerical display Target Data 7} Collision point 8.6.
8.7 Rectifier NBA-797 1) Di mentions Width: 270mm Height © 430mm Depth: 175mm 2) Construction Waterproof construction of wall tapestry type 3) Mass Approx. 18kg 4) Tolerance of input. voltage AC 100/110/115/200/220/230V £15% 50/60Hz, single phase 5) Power consumption 200VA 6) Output DC26,7A 8.8 Cable Length between Equipment Units Maximum cable length Standard cable length 1) From scanner unit to indicator unit, 30m 20m * In case of LIMA-5104 or JAM-51086, the input voltage beyond 24V is required for 30m.
Chapter 9 Installation This chapter has been written for the service technicians to read in case of installation. WARNING S Only specialized personnel shall perform installation work. Installation work performed by personnel other than specialized personnel may cause breakdown of the equipment, poor performance, fire, severe elev-tric shock and other properly and human damages. 9.
9.2 Installing the Scanner Unit 9.2.1 Selecting the installation location CAUTION The scanner unit shall be installed where there are not large obstacles in the direction of the ship's heading line in the same plane. If there is a large impediment in the same plane as the scanner unit, this may cause the generation of floes echoes. In particular, if such floes echoes appear at the ship's heading line, monitoring will be difficult and this may cause inadequate forecasting of danger.
Take the following into consideration when selecting the installation location! (1) Consider the weight of the scanner unit and decide what height it can be raised for installation in the ship. (2) Height at which the scanner unit is installed has to do with the maximum detectable range, the higher ifs position is the better.
9) Note the swing circle of the scanner and allow a distance of at least (swing mm between scanner swing center and other installations (say, mast or radio antenna). Scanner swing circle in the radar of is shown in the following table, Scanner unit Feet Swing circle (mm) Swing encirclement (mm) NEE-2062 4 1220 810 NUKE-2102 6 1910 1156 8.2.2 Installation procedure found that there is no height above the roof of the wheel house enough to directly accommodate a scanner unit, install a pedestal or radar mast.